Dissertations / Theses: 'Ulva'

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Wilkinson, Sarah. "An investigation of protein variation in Ulva lactuca and Ulva rigida under high nitrogen culture conditions." Bachelor's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/25786.

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In the light of findings that abalone achieve higher growth rates when fed on high protein diets, this study attempts to increase the protein content of two macroalgae under culture conditions. Ulva lactuca and U rigida were grown in saturating NH₄⁺ - N (1 mM) and PO₄³⁻P (70 μM ) concentrations. Of the two, protein levels of U. lactuca showed the greatest increase over time. Natural populations had a content of 3.7 % of dry weight. This increased significantly (p <0.05) to a maximum value of 4.5 % after 8 days growth in nutrient enriched conditions. The protein content of U. rigida increased significantly from 3.3 % to 3.9 % after 6 days of growth in nutrient enriched conditions. An interspecies comparison was made using the intertidal species Porphyra capensis, Ulva capensis and Gracilaria gracilis. The highest protein content was found in P. capensis (11.5 %), followed by U capensis (3.0 %) and G. gracilis (2.7 %). Results indicate the suitability of P. capensis as a high-protein abalone fodder. Furthermore, results suggest that the protein content of abalone fodder may be optimized under aquaculture conditions.

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Sampaio, Alexandre Holanda. "Lectins from Ulva and Ptilota species." Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310389.

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Amosu, Albert Oluwatobi. "Using Ulva (Chlorophyta) for the production of biomethane and mitigation against coastal acidification." University of the Western Cape, 2016. http://hdl.handle.net/11394/5324.

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Philosophiae Doctor - PhD In South Africa the green macroalga Ulva armoricana is the main species of macroalgae cultured. The species is currently the largest aquaculture (2884.61 tonnes) product by weight with a corresponding capacity for biogas (CH₄) production. We have shown that biotransformation of U. armoricana to Liquefied Petroleum Gas (LPG) is viable and economically feasible as a clean fuel. pH toxicity tests showed that U. armoricana can be used as a health index, under potentially increased CO₂ concentrations that can occur in IMTA carbon sequestration. We have shown sporulation to be the morphological response to environmental stress, which is indicative of chlorophyll degradation and a reduction in the photosynthetic activity of the alga. With the exception of Cadmium (Cd), the physico-chemical values obtained and the dissolved nutrient/heavy metals uptake by the alga all fell within the FAO/WHO permissible standards. Our Cd values therefore negate the use of these macroalgae for human consumption. We have also shown that U. armoricana can be used in eco-monitoring by playing a significant role in wastewater filtration and bioaccumulation. Nutrient utilization and proximate composition results show that African mud catfish (Clarias gariepinus) grow well on a protein-enriched Ulva diet, suggesting that enriched Ulva has the potential to be a successful fish feed. This thesis suggests among others, that South Africa could take advantage by being the first African country to propose specific standards for edible macroalgae as its successful research innovations and development provides a template for other African countries to further their aquaculture sectors. Additional benefits (bioremediation, ocean de-acidification through the capture of atmospheric and dissolved CO₂ during growth to assist in climate change mitigation) from Ulva farming activities bode well for the aquaculture industry.

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Dang, Thom Thi, Mishima Yasufumi, and Kim Dinh Dang. "Potential of Ulva sp. in biofiltration and bioenergy production." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99448.

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In order to evaluate the effect of seaweeds in bio-filtration for removing nitrogen from marine aquaculture and in bioenergy production, Ulva sp. was used in this study. Experiments were triplicated and run in 3-day incubation at salinities with 30 psu, 10 psu and 5 psu in different initial ammonium nitrogen concentrations from 100 μM to 10,000 μM, equivalently to marine aquaculture conditions. The highest concentrations of ammonium removed were about 690 μmol (12.42 mg) NH4+ at 30 psu, 410 μmol (7.38 mg) NH4+ at 10 psu and 350 μmol NH4+(6.3 mg NH4+) at 5 psu in three days of incubation, while highest growth rates of Ulva sp. were 49% and 150% per day at 500 μM of initial ammonium concentration, similarly to the growth rate reported in microalgae. Moreover, after these experiments, biomass of Ulva sp. has been tested for bioenergy producing goals, because the carbohydrate concentration of this alga was very high, reaching 60-70% of DW. Thus, Ulva sp. can be cultured to remove nitrogen concentration in eutrophication conditions at aquaculture systems in combination with the purpose of bioenergy production after harvesting Để đánh giá hiệu quả của tảo biển trong việc lọc sinh học loại bỏ hợp chất ni tơ từ việc nuôi trồng thủy sản và trong việc sản xuất năng lượng sinh học, Ulva sp. đã được sử dụng trong nghiên cứu này. Các thí nghiệm được lặp lại 3 lần và chạy trong 3 ngày trong tủ ổn nhiệt tại các điều kiện độ mặn 30psu, 10psu, 5psu ở các nồng độ NH4+-N từ 100μM đến 10.000μM, tương đương với điều kiện nuôi trồng thủy sản nước mặn. Nồng độ cao nhất của NH4+-N được loại bỏ khoảng 690 μmol NH4+(12,42mg NH4 +) tại 30psu, 410μmol NH4+(7,38mg NH4+) tại 10psu và 350 μmol NH4+(6.3mg NH4+) tại 5psu, trong đó tỉ lệ sinh trưởng của Ulva sp. là rất cao, sinh trưởng từ 49 đến 150% mỗi ngày tại nồng độ ammonium ban đầu 500 μM tương đương với sinh trưởng của vi tảo. Hơn nữa, sau các thí nghiệm trên, sinh khối của Ulva sp. được thử nghiệm sản xuất năng lượng sinh học vì hàm lượng carbohydrate trong tảo rất cao, chiếm khoảng 60-70% trọng lượng khô của tảo. Như vậy, Ulva sp. có thể được nuôi trồng để loại bỏ hợp chất ni tơ trong điều kiện phú dưỡng của các hệ thống nuôi trồng thủy sản, kết hợp với mục tiêu sản xuất năng lượng sinh học sau thu hoạch

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Alencar, Daniel Barroso de. "ProspecÃÃo quÃmica da macroalga marinha verde Ulva fasciata Delile." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=6565.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico FundaÃÃo de Amparo Ã Pesquisa do Estado do CearÃ As macroalgas marinhas sÃo consideradas fontes promissoras de compostos bioativos para estudos fitoquÃmicos. Tais compostos possuem diferentes propriedades biolÃgicas, funcionando como antibacterianos, antifÃngicos, antivirais, anti-inflamatÃrios, anti-helmÃnticos, antileishmaniose, antimalÃria, antioxidantes, antitumorais cuja utilizaÃÃo como fÃrmacos tem despertado o interesse de muitos pesquisadores. O objetivo deste trabalho foi realizar a investigaÃÃo fitoquÃmica do extrato etanÃlico da macroalga marinha verde Ulva fasciata. O material foi coletado em abril de 2008, na Praia do Pacheco, no municÃpio de Caucaia-CE. As macroalgas in natura foram desidratadas em estufa com recirculaÃÃo de ar a 40ÂC por 15 horas e, em seguida, trituradas, obtendo-se 500 g, os quais foram submetidos primeiramente a uma extraÃÃo a frio com hexano (UFH), e posteriormente com etanol a 70% (UFE). Para o isolamento e a purificaÃÃo dos constituintes fixos foi empregada uma combinaÃÃo de tÃcnicas cromatogrÃficas clÃssicas em que foram isolados UF-1, UF-2 e UF-3. Na amostra UF-1 foi observada a presenÃa de um constituinte majoritÃrio (86,17%) com tempo de retenÃÃo de 24,940 min, cujo espectro de massas o caracterizou por apresentar o Ãon molecular M+ 284. A sugestÃo fornecida pela anÃlise CG-EM e a comparaÃÃo visual do espectro do composto analisado com os da literatura, bem como pela proposta mecanÃstica de formaÃÃo dos principais fragmentos reforÃaram sua identificaÃÃo como hexadecanoato de etila com um Ãndice de similaridade de 96%. Os compostos UF-2 e UF-3 foram encaminhados para o Centro Nordestino de AplicaÃÃo e Uso da RessonÃncia MagnÃtica Nuclear (CENAUREMN) da Universidade Federal do CearÃ, para a determinaÃÃo sua estrutura quÃmica atravÃs de tÃcnicas espectroscÃpicas de RMN 1H e 13C uni- e bidimensionais (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY e TOCSY), bem como por espectrometria de massa (EM). Marine macroalgae have been considered promising sources of bioactive compounds. These compounds exhibit different biological properties, such as antibacterial, antifungal, antiviral, anti-inflammatory, antihelminthic, antileshmaniose, antimalaria, antioxidants, and antitumor. Their use as medicine has spurred the interest of many researches. The objective of this work was to carry out a phytochemistry investigation of the ethanolic extract of green marine macroalga Ulva fasciata. The plant material was collected in April 2008 at Pacheco Beach, Caucaia-CE. Macroalgae in natura were dehydrated in an air-circulation oven at 40ÂC for 15 hours. After the drying process, the material was cut into small pieces. 500 grams were submitted to a cold extraction with hexane (UFH) followed by an extraction with 70% ethanol (UFE). Both isolation and purification from fixed constituents were performed using a combination of classic chromatographic techniques. Three samples were isolated and named UF-1, UF-2 and UF-3. The presence of a major constituent (86.17%) with retention time of 24.940 min was observed in the first sample (UF-1), and its mass spectrum was characterized by the molecular ion M+ 284. The GC-MS analysis suggestion and the comparison of its spectrum with literature reinforce its identification as ethyl hexadecanoate with a similarity index of 96%. Compounds UF-2 and UF-3 have been taken to the Northeastern Center of Application and Use of Nuclear Magnetic Resonance (CENAUREMN) of Federal University of Ceara, to determine the chemical structure by spectroscopy techniques such as uni- and bidimensional (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY and TOCSY) 1H-NMR and 13C-NMR, as well as mass spectrometry (MS).

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Alencar, Daniel Barroso de. "Prospecção química da macroalga marinha verde Ulva fasciata Delile." reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/1126.

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ALENCAR, Daniel Barroso de. Prospecção química da macroalga marinha verde Ulva fasciata Delile. 2010. 68f. Dissertação (Mestrado em Engenharia de Pesca)-Centro de Ciências Agrária,Universidade Federal do Ceará, Fortaleza, 2010. Submitted by Maria Naires Souza (marianaires@ufc.br) on 2011-11-11T19:22:22Z No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2011-11-16T15:00:44Z (GMT) No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) Made available in DSpace on 2011-11-16T15:00:44Z (GMT). No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) Previous issue date: 2010-08-27 Marine macroalgae have been considered promising sources of bioactive compounds. These compounds exhibit different biological properties, such as antibacterial, antifungal, antiviral, anti-inflammatory, antihelminthic, antileshmaniose, antimalaria, antioxidants, and antitumor. Their use as medicine has spurred the interest of many researches. The objective of this work was to carry out a phytochemistry investigation of the ethanolic extract of green marine macroalga Ulva fasciata. The plant material was collected in April 2008 at Pacheco Beach, Caucaia-CE. Macroalgae in natura were dehydrated in an air-circulation oven at 40°C for 15 hours. After the drying process, the material was cut into small pieces. 500 grams were submitted to a cold extraction with hexane (UFH) followed by an extraction with 70% ethanol (UFE). Both isolation and purification from fixed constituents were performed using a combination of classic chromatographic techniques. Three samples were isolated and named UF-1, UF-2 and UF-3. The presence of a major constituent (86.17%) with retention time of 24.940 min was observed in the first sample (UF-1), and its mass spectrum was characterized by the molecular ion M+ 284. The GC-MS analysis suggestion and the comparison of its spectrum with literature reinforce its identification as ethyl hexadecanoate with a similarity index of 96%. Compounds UF-2 and UF-3 have been taken to the Northeastern Center of Application and Use of Nuclear Magnetic Resonance (CENAUREMN) of Federal University of Ceara, to determine the chemical structure by spectroscopy techniques such as uni- and bidimensional (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY and TOCSY) 1H-NMR and 13C-NMR, as well as mass spectrometry (MS). As macroalgas marinhas são consideradas fontes promissoras de compostos bioativos para estudos fitoquímicos. Tais compostos possuem diferentes propriedades biológicas, funcionando como antibacterianos, antifúngicos, antivirais, anti-inflamatórios, anti-helmínticos, antileishmaniose, antimalária, antioxidantes, antitumorais cuja utilização como fármacos tem despertado o interesse de muitos pesquisadores. O objetivo deste trabalho foi realizar a investigação fitoquímica do extrato etanólico da macroalga marinha verde Ulva fasciata. O material foi coletado em abril de 2008, na Praia do Pacheco, no município de Caucaia-CE. As macroalgas in natura foram desidratadas em estufa com recirculação de ar a 40°C por 15 horas e, em seguida, trituradas, obtendo-se 500 g, os quais foram submetidos primeiramente a uma extração a frio com hexano (UFH), e posteriormente com etanol a 70% (UFE). Para o isolamento e a purificação dos constituintes fixos foi empregada uma combinação de técnicas cromatográficas clássicas em que foram isolados UF-1, UF-2 e UF-3. Na amostra UF-1 foi observada a presença de um constituinte majoritário (86,17%) com tempo de retenção de 24,940 min, cujo espectro de massas o caracterizou por apresentar o íon molecular M+ 284. A sugestão fornecida pela análise CG-EM e a comparação visual do espectro do composto analisado com os da literatura, bem como pela proposta mecanística de formação dos principais fragmentos reforçaram sua identificação como hexadecanoato de etila com um índice de similaridade de 96%. Os compostos UF-2 e UF-3 foram encaminhados para o Centro Nordestino de Aplicação e Uso da Ressonância Magnética Nuclear (CENAUREMN) da Universidade Federal do Ceará, para a determinação sua estrutura química através de técnicas espectroscópicas de RMN 1H e 13C uni- e bidimensionais (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY e TOCSY), bem como por espectrometria de massa (EM).

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Murphy, Gerry. "Ecological effects of Ulva lactuca L. in Avon-Heathcote Estuary." Thesis, University of Canterbury. Biological Sciences, 2006. http://hdl.handle.net/10092/1337.

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Macroalgal blooms are increasing world-wide and have negative effects on benthic invertebrates and sediments. These include loss of species diversity and development of hostile sediment environments. This thesis considers ecological effects of Ulva lactuca L., and its mechanical removal on benthic invertebrates and sediments in Avon-Heathcote Estuary, New Zealand. Benthic communities comprised 34 species from 12 groups recorded from seven sites during seasonal general surveys. Dominant groups at each site were Gastropoda and Bivalvia. The most abundant species were Austrovenus stutchburyi, Micrelenchus tenebrosus and Amphibola crenata. Community composition varied significantly between sites, and there were significant site-specific differences in abundances of most species between winter and summer. U. lactuca had the greatest seasonal variation. Several species correlated with U. lactuca biomass, and the strength of correlation for different species varied between sites. There were seasonal changes in sediment physico-chemical variables between sites with greatest change in the silt/clay fraction. The sediment variables silt/clay fraction, dissolved oxygen and temperature correlated with seasonal changes of patterns in benthic community assemblages. A similar study was carried out by Bressington in 2003. In both studies, Bivalvia and Gastropoda were the most abundant groups, with Gastropoda having a higher, and Bivalvia a lower, proportion in the present study compared with 2003. Summer communities were significantly different between the two studies. Compared with 2003 there were higher percentages of sediment pore water and volatile solids present in 2005. Experimental removal of U. lactuca was conducted by mechanical broom at two sites: an open, exposed central sand flat, and McCormacks Bay, a shallow, sheltered mud flat. Removing U. lactuca had several immediate effects. These included a significant decrease in abundance of mobile epifauna (Micrelenchus tenebrosus and Zeacumantus subcarinatus) and an increase in abundance of infauna, including Arthritica bifurca and Austrovenus stutchburyi. There was no effect of U. lactuca removal on Austrovenus stutchburyi condition and 46 days following removal, invertebrate abundances approached pre-removal levels at each site. U. lactuca removal also caused short-term increases in dissolved oxygen and temperature of pore water. The greatest visual impact of removing U. lactuca was to sediments in McCormacks Bay from trampling. It was concluded that the variables having the greatest effect on seasonal species distribution and abundance at each site were temperature and sediment grain size. Differences between the present study and the study in 2003 were due to differences in sampling procedure mainly due to the two different quadrat sizes. Greater accuracy in representing long-term changes in ecosystems would be achieved by using standard sampling protocols. Removal of U. lactuca by mechanical broom was effective and had low impact on benthic invertebrates and physico-chemical variables, but it should be used only in sandy habitats because of severe disturbance to soft-sediment environments. Options for management and control of U. lactuca in Avon-Heathcote Estuary are discussed.

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Briones, Parra Gonzalo Alfonso. "Producción de etanol a partir de la macroalga Ulva rígida." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/111335.

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Ingeniero Civil en Biotecnología Hoy en día el tema de abastecimiento energético es cada vez más importante. En muchos países la matriz energética se basa en la explotación del recurso fósil, principalmente petróleo, el cual es un recurso limitado y que ha tenido una tendencia general al alza de precios. A lo anterior se añade las actuales normativas de emisiones que se están aplicando, las cuales prevén un futuro donde los combustibles fósiles se verán más limitados en su producción y aplicación. Los biocombustibles por tanto han sido una importante alternativa que se ha desarrollado por años, aunque, en un principio, muchos de los biocombustibles diseñados así competían (y compiten) en su materia prima con los recursos alimenticios (biocombustibles de primera generación). Además, una alternativa es el diseño de combustibles basado en residuos industriales, es decir materias primas que no son fuentes alimenticias (biocombustibles de segunda generación). Este estudio busca otra opción de producción de etanol, esta vez a partir de algas para producir biocombustibles de tercera generación, en especial se trabajó con la macroalga verde Ulva rigida. Para alcanzar el objetivo planteado, fue necesario diseñar un procedimiento experimental, el cual consistió en un pretratamiento con ácido diluido (1% y 2% v/v de ácido sulfúrico) a diferentes temperaturas (30°C y 120°C). Después del pretratamiento es necesario neutralizar las muestras para detener dicha reacción. La fracción sólida resultante del pretratamiento es sometida a una hidrólisis enzimática, gracias a la acción de celulasas y celobiasas durante 72 horas (Celluclast® 1,5L - Cat C2730, y Novozyme® 188 - CatC6105). Luego se fermentaron los azúcares liberados en la sacarificación mediante dos estrategias diferentes: Sacarificación y Fermentación Simultáneas (SSF), y Sacarificación Y Fermentación Separadas (SHF). Los resultados mostraron que el pretratamiento no es necesario; las muestras de algas utilizadas presentan azúcares fácilmente hidrolizables, y poseen una baja concentración de lignina, por lo que un pretratamiento con ácido diluido y temperatura no entrega mayor ventaja al proceso. Más aún, dicho procesamiento produce efectos negativos en la concentración de glucosa final. Por lo tanto, este proceso se suprimió del diseño planificado. La sacarificación de las algas sin pretratamiento presentó un rendimiento del 27,2% respecto a la glucosa total de la muestra. Por otra parte, los resultados de las dos estrategias de fermentación SSF y SHF fueron diferentes. El rendimiento, respecto a la conversión de glucosa total de la biomasa, de la estrategia SSF fue de un 50%, considerado alto para ser un primer acercamiento a la utilización de macroalgas. La estrategia SHF presentó un rendimiento del 24,5%. La diferencia de rendimientos indica que la estrategia SSF es mejor, aprovechándose de mejor forma los azúcares constituyentes de las macroalgas y obteniendo una mayor concentración de etanol en solución (5 g/l). Es importante mencionar que dicho rendimiento tiene su base en la composición total de glucosa de la macroalga, por lo que su alto valor puede corresponder a la fermentación de glucosa más la fermentación de otros azúcares no considerados en la composición total de glucosa. Aún así, la estrategia SSF es mejor que la SHF, ya que produce mayor etanol por gramo de biomasa empleado. A partir de los resultados obtenidos, se concluye que se logró un primer acercamiento a la producción de etanol a partir de la macroalga Ulva rigida, diseñándose un proceso de operación y evaluando el pretratamiento de ácido diluido en dicho procedimiento. También se concluyó que la estrategia SSF es mejor que la estrategia SHF para la producción de etanol a partir de la mencionada macroalga. Finalmente, se recomienda complementar este estudio mediante la caracterización completa de la macroalga utilizada.

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Thwala, Sazi Selby. "Investigation of the natural products composition from the seaweed ulva capensis." University of Western Cape, 2019. http://hdl.handle.net/11394/7888.

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>Magister Scientiae - MSc In modern society, diversity of marine macroalgae has become an inspiration for pharmaceutical companies and researchers because of their numerous health benefits, and a great deal of interest has developed towards the isolation of bioactive compounds to identify novel marine natural products that could eventually be developed into therapeutics or pharmaceutical products. Furthermore, marine macroalgae are valuable source of structurally diverse metabolites with scientifically proven reports. The search continues as there are many natural bioactive compounds that are in the womb of the ocean which are still a mystery. Thus, the present study investigates the natural products from green seaweed Ulva capensis.

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Shuuluka, Diina. "Ecophysiological studies of three South African Ulva species from integrated seaweed." Doctoral thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/10903.

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Includes bibliographical references (leaves 210-273). In South Africa, Ulva cultivation is of paramount importance to the marine aquaculture industry. Three local Ulva species (Ulva lactuca Linnaeus, Ulva rigida C. Agardh and Ulva capensis Areschoug) were selected for this research. The first two are currently cultivated on abalone farms for abalone feed and for use as bio-filters, and Ulva capensis was included because it is morphologically and biogeographically distinct from Ulva rigida in nature, despite the inability of molecular methods to separate them. Ulva rigida was collected at I & J farm and from nature at Kommetjie on the southwest of the Cape Peninsula, and U. lactuca was exclusively collected from I & J farm because it could not be found at sites where it had previously been recorded. Ulva capensis was exclusively collected from Kommetjie as this morphological species has not been recorded on abalone farms. The research also aimed to compare U. capensis with U. rigida on a variety of different measures, as molecular studies have suggested that they may represent a single polymorphic species.

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Petersson, Sarah, and Regnström Ebba Larsson. "Planering av en landbaserad odling av Ulva intestinalis på norra Öland." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280475.

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Ulva intestinalis är en fotoautotrof grönalg som är utspridd i stora delar av världen och har ett flertal användningsområden, däribland som matråvara samt som biobränsle. Matindustrin står idag för en fjärdedel av världens utsläpp av växthusgaser. För att FN:s globala mål ska uppnås innan år 2030 måste dessa utsläpp minska. Ett sätt att bidra till att målen nås är att ändra vilka livsmedel som produceras, där alger kan vara en del av den framtida mera hållbara maten. Syftet Med detta arbete var att undersöka möjligheterna för en hållbar algodling för matkonsumtion.Målet var att genom en litteraturstudie hitta en parameter som potentiellt kan påverka tillväxten av Ulva intestinalis och planera ett experiment i en odlingsanläggning på norra Öland som undersöker den valda parametern. I litteraturstudien undersöktes det vilken parameter som skulle kunna testas i en framtida odlingsanläggning. Resultatet som erhölls från litteraturstudien var att substrat är viktigt för algens sporsättning och i kombination med projektets begränsande faktorer blev substrat den parameter som bör testas i experimentet. Utifrån att substrat valdes som parameter lades ett förslag på ett experiment fram. Slutligen diskuterades potentiella felkällor samt så gavs det förslag på eventuella fortsatta studier. Ulva intestinalis is a photoautotroph green algae that is found in large parts of the world, and has a variety of uses, for example as food and as biofuel. The food industry is responsible for one fourth of the world’s green gas emissions, and for the United Nations’ Sustainable Development Goals to be reached before the year 2030, these emissions must be reduced. One way to contribute to the achievement of these goals is to change what kind of food is being produced,and algae could be part of the more sustainable future food. The purpose with the project was to examine the possibilities for a sustainable land-based algal cultivation for food use. The goal was to find a parameter that could potentially influence the growth of Ulva intestinalis, and to plan an experiment in a cultivation plant in northern Öland that examines the selected parameter. The method that was selected to fulfill the goal of the project was a literature study, in which some potential growth parameters were identified, so a conclusion of which parameter should be tested in a future experiment could be made. The result from the study was that substratum is important for the settlement of the spores, and in combination with the limits of the project it was chosen to be the parameter to be tested in the planned experiment. On the basis of substratum as the selected parameter, a proposal for an experiment was presented. Finally, potential sources of error were discussed, and suggestions for future studies were made.

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Consuegra, Valenzuela Verónica Angélica. "Extracción de antioxidantes polifenólicos desde macroalgas macrosystis pyrifera y ulva rígida." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/132021.

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Memoria para optar al título de Ingeniera Civil en Biotecnología Las algas se utilizan desde tiempos inmemoriales para consumo humano y extracción de subproductos. Entre los más conocidos estas los ficocoloidales como el alginato, agar y carragenano, de gran valor en la industria alimenticia. Actualmente, existe interés por la utilización de biomasa algal en la producción de biocombustibles, lo cual abre una potencial explotación de otros subproductos de algas, creando procesos sustentables y amigables medioambientalmente. Dadas las condiciones naturales extremas en que se desarrollan estos organismos, uno de los compuestos de mayor interés que producen son los antioxidantes, moléculas bioactivas de distinta naturaleza, ya sea carbohidratos, lípidos, terpenoides y compuestos polifenólicos. En el marco del proyecto de cooperación CONICYT-Chile AKA-Finlandia (AKA ERNC-009) para la producción de biocombustibles de tercera generación, se plantea la obtención de compuestos polifenólicos con actividad antioxidante como subproducto, afectando mínimamente la degradación de los azúcares disponibles en las algas, para su utilización en biocombustible El presente trabajo consistente en la determinación de las mejores condiciones de extracción de compuestos antioxidantes polifenólicos desde macroalgas verdes (Ulva rigida) y pardas (Macrocystis pyrifera), evaluando diferentes variables: solvente, tiempo de extracción, temperatura de extracción y relación sólido líquido. Para ello se empleó un diseño experimental estadístico basado en el método Taguchi. Para este diseño se realizó un extenso análisis de la literatura existente en torno al tema y selección de los métodos de evaluación de actividad antioxidante, condiciones y metodología de extracción. Se cuantificó los compuestos fenólicos totales por método de Folin-Ciocalteu, capacidad antioxidante por reducción del radical DPPH y las azúcares reductores por método del ácido 3,5-dinitrosalicílico. Los resultados obtenidos se analizaron por métodos estadísticos, utilizando Análisis de Componentes Principales para determinar los factores que aportan mayor variabilidad a la actividad antioxidante durante el proceso extractivo. Como principales resultados fue que se seleccionó el alga M. pyrifera como fuente de antioxidantes polifenólicos. Se logró determinar una metodología que permite extraer una cantidad de polifenoles totales de 374,4 ± 27,4 [mg GAE/100gPS], actividad de 84,9 % de captura del radical DPPH y ausencia de azúcares reductores en el extracto bioactivo. Las mejores condiciones de extracción determinadas corresponden a utilizar como solvente etanol al 75%, una relación sólido-líquido de 1:10 p/v, temperatura de extracción de 37°C por 180 minutos, siendo el tiempo de extracción el factor con mayor efecto en el tratamiento de extracción determinado por el Análisis de Componentes Principales. El método desarrollado sirve como primera aproximación al potencial del alga parda como fuente de antioxidantes industriales y siendo un punto de partida en un proceso de optimización. Estos resultados representan un rendimiento másico de los polifenoles extraídos de un 0,4%. Considerando los niveles de producción actual de M.pyrifera en la X región del país se lograría una producción de alrededor de 2 ton/año de antioxidantes polifenólicos desde el alga, representando un 0,015% del mercado global de polifenoles al año 2011. Este valor podría ser promisorio si se piensa en las posibilidades de aumentar el cultivo de estas algas en la región.

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Gao, Guang. "Developing systems for the commercial culture of Ulva species in the UK." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3313.

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The green seaweed, Ulva, is highly valued in terms of animal feed, food and biofuel, as well in the delivery of crucial remediation services including wastewater treatment and CO2 removal. Accordingly, Ulva cultivation has gained significant research interest worldwide. Notwithstanding these research efforts, Ulva cultivation is still in its infancy and knowledge to underpin such developments remains limited. A common challenge in Ulva cultivation is the fluctuating productivity with time due to vegetative fragmentation and/or periodic reproduction. In this study, three methods were employed to address this challenge. Firstly, culture conditions were optimised to establish a balance between growth and reproduction. Secondly, a refined culture method was developed, which more than tripled growth of Ulva over an 18-day cultivation as compared to a standard method. Thirdly, a sterile strain was obtained by mutating a wild strain with ultraviolet radiation. This new strain grew five times faster over an 18-day cultivation and absorbed nitrate and phosphate 40.0% and 30.9% quicker compared to the wild strain respectively. The chemical composition of the sterile strain showed a lipid content of more than double that of the wild strain, while the protein content was 26.3% lower than the wild strain. Several tissue preservation techniques were developed to enable settlement and growth trials to be conducted on demand. The merits or otherwise of the preservation techniques were determined for gametes, germlings and thalli. In addition to cultivation-related techniques, the co-effects of climate change factors (global warming and ocean acidification) and eutrophication on Ulva cultivation were investigated. These three variables interacted in a complex pattern to differentially affect life history stages, as well as altering the chemical composition and functional properties of Ulva. These findings make tangible contributions to the ability to successfully and commercially cultivate Ulva in terms of culture conditions, tissue preservation and the development of mutant strains. Further, by placing Ulva culture in a climate change context, this work provides valuable insight into the limits to resilience of Ulva to a changing climate. This will inform the future development of the Ulva culture industry over the coming decades.

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Du, Plessis Darren Scott. "Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla." Bachelor's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/12766.

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Includes bibliographical references. Identifying the chemical compounds that attract urchins to seaweeds will increase sea urchin aquaculture efficiency as these compounds can be utilized in the production of artificial feeds enhancing their attractiveness and palatability. This study investigated the chemosensory preferences of the tropical sea urchin Tripneustes gratilla for four crude extracts of Ulva as well as Fresh Ulva and an artificial feed. The four crude extracts of Ulva (Methanolic, Ethanolic, Chloroform and Chloroform-Methanol extracts) were tested by pair-wise chemosensory trials in a Y shaped maze. Urchins were significantly deterred by both the Chloroform and Chloroform- Methanol extracts as well as the solvent controls and artificial feed, however T. gratilla was significantly attracted to both the Methanolic and Ethanolic extracts. These two extracts were tested individually against Ulva and the urchins could not distinguish between Ulva and the extracts. When these two extracts were tested against one another it was found that the urchins were significantly attracted to the Methanolic extract. The Methanolic extract was then added to the artificial feed and significantly improved the feeds attractability. This indicates that these extracts, or the compounds which are responsible for this effect, can be incorporated into artificial feeds thereby making them more attractive to the sea urchin. The percentage yield of Ulva that each solvent extracted was different, although only the Ethanolic extract was found to be significantly different from the Chloroform and Chloroform-Methanol extracts. Future studies are needed to examine the chemical composition of these specific chemosensory compounds. By incorporating these attractive extracts into artificial feeds, South Africa can potentially improve the cultivation success of T. gratilla therefore expanding the economy of the local aquaculture industry through the export of this highly valued seafood product.

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Joska, M. A. P. "Taxonomy of Ulva species (Chlorophyta) in the South Western Cape, South Africa." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/21712.

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Bibliography: pages 88-95. Six species of Ulva, U. atroviridis Levring, U. capensis Areschoug, U. fasciata Delile, U. lactuca L., U. rigida C.Agardh and U. uncialis Kutzing, have been reported to occur in the south western Cape Province. As a result of herbarium, field and culture studies it was found that five of these species do occur, but U. uncialis is a synonym of U. riqida (Agardh, 1883). Furthermore, U. atroviridis has correctly been reassigned to the genus Enteromorpha (Wynne, 1986). U. rhacodes (Holmes) Papenfuss, which has hitherto only been reported from the eastern Cape Province, was also found, giving a total of five species of Ulva in the region, which are described in detail. Chloropelta caespitosa Tanner, a new genus and species, previously only recorded from the north east Pacific, was also found in False Bay and at Cape Hangklip during the course of this study. This genus has a germling which, during the initial phase of its growth resembles the germlings of both Ulva and Enteromorpha. Its further development differs however in that its monostromatic thallus becomes distromatic through cell division and not joining together of the monostromatic layers.

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de, Jager Kristin. "Microorganisms associated with ulva grown in abalone effluent water: implications for biosecurity." Master's thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33618.

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Macroalgae such as Ulva are living hosts that are known to perform essential roles in marine ecosystems, and are extensively utilised for several aquaculture operations, including in the integrated production of high value goods such as abalone. Intensive aquaculture operations along the coastline release effluent water into the surrounding coastal waters, which has adverse impact on the environment. As a means to bioremediate abalone effluent, several commercial abalone farms in South Africa use Ulva as a biofilter, after which the Ulva may serve as a feed source for the abalone. Advancements in gene sequencing technology has enabled the assessment of large scale 16S rRNA gene libraries of near full-length sequences. However, studies concerning the epiphytic bacterial communities present on macroalgae grown in effluent systems are scarce, and as a result several commercial farmers have become sceptical about utilising effluent grown Ulva as feed. This study addresses the biosecurity implications associated with the use of Ulva as a biofilter and feed within an integrated multitrophic aquaculture (IMTA) system along with the abalone Haliotis midae by assessing the bacterial communities associated with Ulva and its environment. Water and Ulva samples were collected from an integrated abalone farm along the Western Cape of South Africa and assessed via a culture and a non-culture-based approach. Samples were collected from both fertilised seawater tanks and abalone effluent wastewater raceways. The water samples were collected at the inlets and outlets of each tank/raceway and the Ulva was collected from within each system. The culture-based approach utilised three selective media for the isolation and quantification of culturable bacteria, namely Tryptic Soy Agar (TSA, a general growth media), thiosulfate-citrate-bile-sucrose (TCBS) agar (vibrio selective growth media), and Ulvan agar plates, where the primary carbohydrate of Ulva was utilized as the main carbohydrate source. Post isolation, selected bacteria underwent 16S rDNA gene analysis for identification. The non-culture-based approach utilised the next generation Illumina 16S Metagenomic Sequencing platform (MiSeq). Moreover, the Ulva was sequenced using the rbcL gene to identify the species grown in the aquaculture system. Phylogenetic analysis of Ulva suggests that it falls within the U. rigida clade. The sequenced Ulva cultivated at I&J abalone farm shared close similarity with Ulva rigida (KP233772) and Ulva scandinavica (EU484416) on the GenBank database, and hence was referred to with the name of its corresponding molecular synonym, i.e. U. rigida. The culture-based results indicate that bacterial numbers were significantly higher in the raceways receiving abalone effluent water when compared with the Ulva tanks receiving seawater that were fertilized. Bacterial abundance on all three selective media types was higher on the Ulva cultured in the abalone effluent raceways than on the Ulva cultured in the fertilized seawater tanks. Moreover, it was observed that the Ulva has the potential to significantly reduce the bacterial load of abalone effluent water raceways. Rarefaction results from the non-culture-based approach indicate that the Ulva in both the fertilised seawater and abalone effluent raceways had significantly lower bacterial alpha diversity than the water columns themselves. Principal co-ordinate analysis (PCoA) at phylum level showed that bacterial communities on the Ulva and in the water, columns shared similar phyla diversity. Alternatively, PCoA at genus level demonstrated that microbial communities residing on the Ulva (both effluent and fertilised seawater grown Ulva) had significant differences compared with the water samples obtained from both the inlets and outlets of the effluent and fertilised seawater systems. When assessing the differential abundant bacteria on the Ulva, general marine bacteria appear in high abundance and potentially pathogenic bacteria such as Vibrio appear in low abundance. Moreover, the presence of the Ulva within the wastewater seemed to decrease the bacterial abundance of Vibrio within the fertilised seawater tanks as well as the abalone effluent raceways. Despite the presence of potentially pathogenic bacteria within the abalone effluent raceways, the Ulva does not seem to act as a sink for potentially pathogenic bacteria indicating that feeding effluent grown Ulva to abalone is not of significant biosecurity concern. Even though several commercial abalone farmers consider recirculation within aquaculture feed systems high-risk technology, no papers have reported disease outbreaks due to the use of effluent grown Ulva as abalone feed. These results provide a general basis for the dynamic changes in the bacterial community profiles in a commercial abalone farm associated with utilising effluent grown Ulva as a feed additive for abalone. This effort to profile the bacteria associated with Ulva and its environment under fertilised and effluent conditions provides deeper insight on understanding the biosecurity implications of incorporating effluent grown Ulva into abalone feed.

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Araujo, Clarissa Lourenço de. "Estudo experimental da acumulação de metais por Ulva SP e Ruppia Maritima." Niterói, 2016. https://app.uff.br/riuff/handle/1/1662.

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Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-04-28T18:18:17Z No. of bitstreams: 1 Tese Clarissa Lourenço de Araujo.pdf: 7002934 bytes, checksum: 52d368f8ad6a751f994f7846928d0854 (MD5) Made available in DSpace on 2016-04-28T18:18:17Z (GMT). No. of bitstreams: 1 Tese Clarissa Lourenço de Araujo.pdf: 7002934 bytes, checksum: 52d368f8ad6a751f994f7846928d0854 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ Este estudo teve como objetivo contribuir para caracterização do processo de incorporação biológica de metais por duas espécies fitobentônicas, a macroalga Ulva sp. e a macrófita aquática Ruppia maritima, para subsidiar futuras atividades de monitoramento da contaminação da biota aquática da Lagoa Rodrigo de Freitas por metais, bem como de outros sistemas costeiros com condições semelhantes. Este estudo baseou-se na realização de experimentos laboratoriais com o radiotraçador 51Cr (nas formas tri e hexavalente) e com Cr, Cu, Hg, Mn, Pb e Zn, para caracterizar a cinética de incorporação destes pelas duas espécies fitobentônicas. As amostras coletadas na Lagoa Rodrigo de Freitas, foram aclimatadas em laboratório e posteriormente submetidas a experimentos onde foram simuladas condições de mistura de águas salinas e fluviais com água marinha artificial de salinidades 7, 15 e 21‰ e de eventos de aumento dos níveis de matéria orgânica na coluna d’água através da adição de ácidos húmicos. A fim de elucidar os processos de sorção e incorporação de metais foram aplicadas ainda, técnicas de remoção de biofilme e de limpeza do material biológico em solução de EDTA. Nos ensaios com 51Cr (III e IV) foi observada que acumulação do metal por Ulva sp. possui relação inversa com a salinidade, enquanto para R. maritima, o máximo de acumulação ocorre em salinidade 21‰. Nos experimentos com adição simultânea de metais foi observada a seguinte ordem de abundância Pb>Zn>Hg>Cu>Mn>Cr. A maior acumulação dos metais foi observada em salinidade 15‰, com exceção apenas do Hg que apresentou máximo de incorporação em salinidade 21% para alga. Nos ensaios com adição de substâncias húmicas foi evidenciada a redução da incorporação de Cu, Pb e Zn por ambas espécies. No tocante ao potencial de acumulação, foi verificada a maior habilidade de sorção de metais por Ulva sp., independentemente da faixa de salinidade aplicada. Nos ensaios de remoção do biofilme aderido a R. maritima foi observada a redução das concentrações de Cu, Mn e Pb, reforçando o papel deste componente na acumulação de íons metálicos por macrófitas aquáticas. Por fim, no ensaio em que o material biológico foi lavado em solução de EDTA, foi observada a tendência de adsorção superficial de Cu, Mn e Pb, enquanto Cr e Zn, são rapidamente internalizados nos tecidos da macrófita. This study aims to contribute to the characterization of the process of biological incorporation of metals by two benthonic species, the macroalgae Ulva sp. and the aquatic macrophyte Ruppia maritima, to subsidize future activities of monitoring the contamination of aquatic biota of the Rodrido de Freitas Lagoon for metals, as well as other coastal systems with similar conditions. This study was based on laboratory experiments with the radiotracer 51Cr (in forms tri and hexavalent) and with Cr, Cu, Hg, Mn, Pb and to characterize the kinetics of incorporation of these by two phytobentic species. Samples collected in the Rodrigo de Freitas Lagoon were acclimated in the laboratory and subsequently subjected to experiments where conditions of saline and river water mixed with artificial marine water with salinities of 7, 15 and 21‰ were simulated as well as events that increase the levels of organic matter in the water column through the addition of humic acids. In order to elucidate the processes of sorption and incorporation of metals, techniques for the removal of biofilm and the cleaning of biological material in EDTA solution were also applied. In tests with 51Cr (III and IV) it was observed that accumulation of the metal in Ulva sp. has inverse relationship with salinity, while for R. maritima, the maximum accumulation occurs in salinity 21 ‰. In the experiments with simultaneous addition of metals, the following order of abundance was observed Pb>Zn>Hg>Cu>Mn>Cr. The higher accumulation of metals was observed in salinity 15 ‰, with the exception of Hg that showed maximum incorporation in salinity 21% for algae. In tests with addition of humic substances, the reduction in the incorporation of Cu, Pb and Zn both species was evidenced. In regards to the potential for accumulation, it was verified the greater capability of sorption of metals by Ulva sp., regardless of range of salinity applied. In tests of removal of biofilm attached to R. maritima, the reduction of concentrations of Cu, Mn and Pb was observed, reinforcing the role of this component in the accumulation of metal ions by aquatic macrophytes. Finally, in the biological test material that was washed in EDTA solution, the tendency of surface adsorption of Cu, Mn and Pb was observed, while Cr and Zn are rapidly internalized in the tissues of macrophyte.

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18

Santos, Janaina Pires. "Perfil antioxidante e bioatividade de três espécies de macroalgas da Praia do Morro de Pernambuco no litoral Sul da Bahia, Brasil." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-03012017-142742/.

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As macroalgas desempenham importante papel no ambiente marinho como produtores primários. Elas ocupam diversas zonas do costão rochoso, entre elas, o mediolitoral que é a mais estudada devido às rápidas mudanças nos fatores ambientais (temperatura, dessecação, irradiância, salinidade, entre outros) direcionados pela dinâmica das marés. Esse dinamismo, fez com que os organismos desenvolvessem defesas que garantissem a sua sobrevivência nesses ambientes. E essas defesas, na maioria das vezes química, também possuem utilidade e aplicações biotecnológicas, pois as algas são fonte de novas substâncias e bioatividade com importância nutricional, médica ou farmacêutica. Como forma de reconhecer o potencial químico e bioativo ainda subexplorado nas algas brasileiras, o presente trabalho avaliou o potencial, antioxidante, antiviral, citotóxico, aspectos da fisiologia e a caracterização de ácidos graxos de três espécies de macroalgas do nordeste brasileiro: Sargassum vulgare (Ochrophyta), Palisada flagellifera (Rhodophyta), e Ulva fasciata (Chlorophyta) e seus potenciais foram testados para diferentes extratos. As espécies apresentaram bom potencial inibitório da enzima transcriptase reversa do vírus HIV e essa bioatividade se mostrou mais promissora, pois os extratos apresentaram baixa citotoxicidade frente ao crustáceo Artemia salina. O potencial antioxidante foi considerado bom para todas as espécies tanto para os extratos com finalidade química, tanto para os extratos com finalidade fisiológica, e este último, aliado às repostas fisiológicas de constituição pigmentar e proteínas sugerem que as algas desse estudo possuem uma boa aclimatação ao ambiente, pois não foi notada expressivas variações no seu conteúdo pigmentar. Quanto à caracterização de ácidos graxos, P. fagellifera se mostrou a maior fonte de ácidos graxos poliinsaturados (AGPIs) entre as espécies estudadas, o que faz dela um potencial recurso para obtenção de AGPIs com importância na suplementação alimentar como possíveis nutracêuticos e de importância médica The macroalgae plays an important role in the marine environment as primary producers. They occupy different parts of the rocky shore, among them the midlittoral which is the most studied due to rapid changes in environmental factors (temperature, desiccation, irradiance, salinity, etc.) influenced by the dynamics of the tides. This dynamism, made the organisms developed defenses that guarantee their survival in these environments. These defenses, mostly chemical, also have utility and biotechnological applications because the algae are a source of new substances and bioactivity with nutritional importance, medical or pharmaceutical. As a way to recognize the chemical and bioactive potential still underexploited in Brazilian seaweed, this study evaluated the potential, antioxidant, antiviral, cytotoxic, aspects of physiology and fatty acids characterization of seaweeds in northeastern Brazil Sargassum vulgare (Ochrophyta) Palisada flagellifera (Rhodophyta) and Ulva fasciata (Chlorophyta) tested for different extracts. The species showed good potential as inhibitors of the enzyme reverse transcriptase of HIV and this bioactivity was more promising because the extracts showed low cytotoxicity against the crustacean Artemia salina. The antioxidant potential was considered good for all species for both the extracts with chemical purposes, for both the extracts with physiological purpose, and the latter coupled to the physiological responses of pigment composition and proteins suggest that the algae of this study have good acclimation environment, it was noted significant variations in their pigment content. The characterization of fatty acids, P. fagellifera showed the largest source of polyunsaturated fatty acids (PUFAs) among the studied species, making it a potential resource for obtaining PUFAs of importance in the food supplementation as possible nutraceutical and medical importance

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Costa, Vanessa Macedo Freire da. "Utiliza??o da macroalga Ulva lactuca linnaeus na redu??o de nutrientes (NH4+,NO3- e PO4-2) provenientes da carcinicultura." Universidade Federal do Rio Grande do Norte, 2006. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12503.

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Made available in DSpace on 2014-12-17T14:02:02Z (GMT). No. of bitstreams: 1 VanessaMFC.pdf: 1244215 bytes, checksum: 2d84570105aa3f980f60bc5ac24ab268 (MD5) Previous issue date: 2006-09-11 Dentre as macroalgas capazes de absorver altas concentra??es de N e P dissolvidos na ?gua, destaca-se a Chlorophyta Ulva lactuca, bastante adapt?vel e resistente ?s adversidades ambientais, como grandes varia??es de temperatura, salinidade, mat?ria org?nica e metais pesados. Trata-se tamb?m de uma esp?cie bastante comum nas ?reas intertidais do litoral norte-riograndense. Devido a suas caracter?sticas ecol?gicas, fisiol?gicas e nutricionais, foi avaliado nesse estudo, o seu potencial como biofiltro na redu??o de NH4+, NO3- e PO4-2, tanto em condi??es controladas como tamb?m em um viveiro de camar?o. No experimento laboratorial, foram utilizados quatro aqu?rios de vidro de 30 x 20 x 20cm com 10L de ?gua, sendo tr?s aqu?rios experimentais contendo 20g de U. lactuca e um controle. O acr?scimo de biomassa foi de 2,92g (22,92 ? 6,29g; p < 0,05) em rela??o ao in?culo inicial de 20g, sob temperatura (28,50 ? 0,58?C), salinidade (35,00 ? 0,00 ), pH (8,26 ? 0,02) e luz constante (250 μmol.m2s-1). O crescimento positivo (1,78 ? 4,38%dia-1; p < 0,05), juntamente com a alta efici?ncia de absor??o de am?nio (83%; p < 0,001), nitrato (83%; p < 0,001) e ortofosfato (53%; p < 0,001), demonstrou que, nessas condi??es, a Ulva lactuca absorveu os nutrientes e aumentou sua biomassa. J? no experimento de campo, realizado na fazenda TECNAR?O, situada no munic?pio de Arez/RN (06? 11 40 Latitude Sul, e 35? 09 37 Longitude Oeste), foram utilizadas tr?s gaiolas de PVC, posicionadas a 12cm da superf?cie da ?gua, cada uma com dimens?es de aproximadamente 59 x 59 x 15cm, onde foram colocadas 200g de U. lactuca. O ganho de biomassa de 3g (203,00 ? 41,02g; p < 0,001) foi muito semelhante ?s condi??es controladas, demonstrando a adaptabilidade da esp?cie em condi??es ambientais vari?veis, onde, apesar da temperatura pouco vari?vel (27,45 ? 0,64?C), houve progressiva diminui??o de salinidade (25 - 15 ), devido ao per?odo de fortes chuvas (34,70 ? 23,78mm). Somado a isso, foram observados v?rios fatores biol?gicos interferindo no viveiro, como a presen?a de ep?fitas, organismos endof?ticos, fouling e a herbivoria por parte dos pr?prios camar?es. Houve aumento nas concentra??es de NH4+ (4,36 ? 1,69 μmol.L-1), NO3- (0,17 ? 0,25μmol.L-1) e PO4-2 (0,41 ? 0,13μmol.L-1), coincidindo com o crescimento da esp?cie at? a terceira semana. Todos os par?metros ambientais analisados, assim como a biomassa e a Taxa de Crescimento Relativo (TCR), obtidos no campo, apresentaram varia??es altamente significativas (p < 0,001). As correla??es observadas entre biomasa e NH4+ (r = 0,82; p < 0,001) e entre biomassa e PO4-2 (r = 0,87; p < 0,001), indicam que esta esp?cie ? capaz de ter um crescimento satisfat?rio nas condi??es eutr?ficas de um viveiro de camar?o, sendo poss?vel seu uso como biofiltro.

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Salim, Douaa. "Formulations écocompatibles d'extraits de l'algue verte Ulva Lactuca pour la préservation des agrumes après récolte." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0128.

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La culture des agrumes est l'une des plus répandues, dans les pays méditerranéens. Cependant, ces agrumes sont exposés à de nombreuses maladies post-récolte, généralement causées par le pathogène « Penicillium digitatum ». Plusieurs fongicides chimiques utilisés pendant des décennies, se sont révélés nocifs pour la santé et l'environnement. Le contexte sociétal et règlementaire évoluant, de nouvelles stratégies sont envisagées pour tendre vers des solutions plus sûres. C'est pourquoi, les travaux visent à développer un biopesticide utilisant les molécules naturelles issues d'une algue verte pour la protection des agrumes. Or, l'action des molécules actives dépend de la méthode de formulation. Les algues vertes Ulva lactuca sélectionnées pour cette étude sont présentes en abondance sur les zones côtières Libanaises. Plusieurs extraits ont été réalisés par macération à l'aide de solvants verts (eau, éthanol, acétate d'éthyle) pour obtenir différentes compositions en métabolites secondaires. Parmi ces molécules lipophiles ou hydrophiles, certaines sont à l'origine de l'activité anti-fongique détectée pour les extraits. Le mécanisme d’action des fractions actives (extraits bruts et chlorophylles isolées) sur P. digitatum a été étudié en mesurant l’activité des enzymes de défense des cellules des agrumes. Les enzymes -1,3-glucanase et peroxydases ont été identifiées comme étant responsables de la dégradation de la paroi cellulaire fongique. De plus, afin de préserver l'activité des extraits aqueux pendant plusieurs mois, une microencapsulation par atomisation a été réalisée à l’aide de biopolymères. Afin de limiter la consommation en molécules actives et de faciliter leur adhérence à la surface des fruits, l'extrait aqueux d'Ulva lactuca a été formulé sous forme d'une émulsion huile-dans-eau. Pour cela, des émulsifiants biosourcés ont été synthétisés en respectant les principes de la chimie verte. Le caractère amphiphile de ces aconitates ayant été mis en évidence, ils se sont avérés capables de stabiliser une émulsion contenant l'extrait aqueux d’Ulva lactuca. Plusieurs tests microbiologiques ont montré l'efficacité des nouveaux ingrédients (fraction aqueuse et agent émulsifiant) vis-à-vis de la multiplication, de l’adhésion et de la germination du Penicillium digitatum. Ainsi, la mise en émulsion de l'extrait aqueux optimise son activité anti-fongique, en assurant une diffusion homogène des molécules actives vers la surface à traiter, puis en formant un film d’huile protecteur. Enfin, des tests in vivo sur 6 semaines ont montré que les émulsions et l’extrait aqueux permettent de réduire de façon importante le taux d’infection des oranges. En conclusion, ces travaux proposent des ingrédients naturels ou biosourcés mis en oeuvre par des procédés écocompatibles pour apporter une solution alternative à la conservation des agrumesaprès récolte Citrus cultivation is one of the most widespread in the Mediterranean countries. However, these citrus fruits are exposed to many post-harvest diseases, usually caused by the pathogen "Penicillium digitatum". Several chemical fungicides used for decades have proven to be harmful to health and the environment. With the societal and regulatory context evolving, new strategies are being considered to move towards safer solutions. Therefore, the work aims to develop a biopesticide using natural molecules from a green alga for the protection of citrus fruits. However, the action of the active molecules depends on the method of formulation. The Ulva lactuca green algae selected for this study are abundant in the Lebanese coastal areas. Several extracts were made by maceration with green solvents (water, ethanol, ethyl acetate) to obtain different compositions of secondary metabolites. Among these lipophilic or hydrophilic molecules, some are at the origin of the anti-fungal activity detected for the extracts. The mechanism of action of active fractions (crude extracts and isolated chlorophylls) on P. digitatum was studied by measuring the activity of the defense enzymes of citrus cells. The enzymes -1,3- glucanase and peroxidases have been identified as being responsible for fungal cell wall degradation. In addition, in order to preserve the activity of the aqueous extracts for several months, microencapsulation by atomization was carried out using biopolymers. In order to limit the consumption of active molecules and to facilitate their adhesion to the fruit surface, the aqueous extract of Ulva lactuca was formulated in the form of an oil-in-water emulsion. For that, biosourced emulsifiers were synthesized respecting the principles of green chemistry. The amphiphilic character of these aconitates gives them, the ability to stabilize an emulsion containing the aqueous extract of Ulvalactuca. Several microbiological tests showed the effectiveness of the new ingredients (aqueous fraction and emulsifying agent) towards the multiplication, adhesion and germination of Penicillium digitatum. Thus, the emulsification of the aqueous extract optimized its anti-fungal activity,ensuring a homogeneous diffusion of the active molecules to the surface to be treated, then forming a protective vegetable oil film. Finally, in vivo tests over 6 weeks indicated that emulsions and aqueous extract can significantly reduce the infection rate of oranges. In conclusion, this work proposes natural or biobased ingredients implemented by ecocompatible processes to provide an alternative solution to citrus fruit postharvest preservation

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Tujula, Niina Amanda Biotechnology &amp Biomolecular Sciences Faculty of Science UNSW. "Analysis of the epiphytic bacterial community associated with the green alga Ulva australis." Awarded by:University of New South Wales. School of Biotechnology and Biomolecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/25197.

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Epiphytic bacterial communities on the surfaces of marine algae are poorly characterised. Most information available on marine bacterial epiphytes is derived from culture-based studies. With the rapid development of molecular community analysis technologies, it is now possible to obtain a more comprehensive picture of marine microbial populations on living surfaces. The intertidal macroalga Ulva australis, belongs to the cosmopolitan group of green marine algae (Ulvales) known to require the presence of bacteria for normal growth and has been suggested to employ specific bacteria for the defence against fouling by micro- and macro-organisms. This thesis has examined the composition and structure of the surface associated bacterial community on Ulva australis using 16S rRNA gene clone library, denaturing gradient gel electrophoresis (DGGE), and catalysed reporter deposition ??? fluorescence in situ hybridisation (CARD-FISH) analysis. The 16S rRNA gene clone library revealed that the five main bacterial groups present in the surface associated community were Bacteriodetes, Planctomycetes, Alpha-, Gamma-, and Delta-Proteobacteria. Twenty-two sequence phylotypes were identified, suggesting that the epiphytic community was of relatively low diversity. A clone similar to an algal morphogenesis inducing Cytophaga strain was identified, indicating that U. australis harbours bacteria important for thallus structural maintenance. DGGE analysis showed that while the bacterial community varied over spatial and temporal (seasons) scales it also included a stable subpopulation consistently associated with the seaweed surface. Sequencing of selected DGGE bands suggested that members of the Alphaproteobacteria and the Bacteriodetes belonged to the stable subpopulation. Using CARD-FISH with different phylogenetic probes demonstrated that Alphaproteobacteria (~ 70%) and Cytophaga-Flavobacteria (~13%) constituted the majority of bacterial cells on the surface of U. australis. A comparison of the results provided by the molecular community analysis methods, employed in this thesis, and those of culturing of epiphytic bacteria from U. australis revealed that each approach provides different patterns of phylogeny and extent of diversity. For example, the culture collection and the clone library detected a relatively high amount of Gammaproteobacteria, however, DGGE and CARD-FISH did not. Also, low species diversity clone sequences and isolates of Alphaproteobacteria contrasted with the high numbers detected by the DGGE analysis. In addition to the phylogentic determination of the epiphytic bacterial community, CARDFISH was also used to assess the organisation and distribution of bacterial cells across different zonal regions on seaweed surface. It was found that approximately 40% of bacterial cells clustered in aggregates, or microcolonies. These aggregations were considered to be heterogeneous in composition and were mainly comprised of multiply species. The occurrence of more non-viable solitary single rather than aggregated cells suggests that aggregates might offer greater protection to bacterial cells from the harsh conditions in the intertidal zone. More broadly, CARD-FISH was found to be a useful tool for studying microcolonies and was also successfully applied to detect slow growing soil microcolonies cultivated using a novel soil substrate membrane system culturing technique without the need to perform an rRNA enrichment incubation. The findings in this thesis, as described from the application of a number of molecular community analysis techniques such as clone library, DGGE and CARD-FISH, have improved our understanding of the diversity and structure of the epiphytic bacterial community associated with U. australis. Morevover, the information provided may to design future studies in the ecology of bacteria-seaweed interactions, including symbiotic interactions, and aid in marine biotechnology applications such as identifying bacteria which produce bioactive secondary metabolites.

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Serpa, Dalila do Rosário Encarnação. "Macroalgal (Enteromorpha spp. and Ulva spp.) primary productivity in the Ria Formosa Lagoon." Master's thesis, Faculdade de Ciências e Tecnologia, 2005. http://hdl.handle.net/10362/12085.

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Etwarysing, Lekraj. "Variation in chemical components of aquacultured Ulva (Chlorophyta) in response to environmental variables." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/22030.

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A detailed literature review of relevant Ulva biology and chemical composition is included. Marine algae are known to produce a wide range of volatile organic compounds that are primarily used in chemical communications. These compounds are released in seawater and act as either pheromones or allelochemicals. Aldehydes have been reported to be the main group of volatile compounds in green algae Ulva. Cultivation of Ulva as feed on abalone farms in South Africa has been a success but there has been little research on the chemistry of South African Ulva. This study aims to investigate the potential effects of environmental variables and grazing on the chemical profile, and specifically on the aldehyde-type natural products produced (δH 9.00 - 10.50) by laboratory cultured Ulva using ¹H NMR spectroscopy and multivariate statistical analysis. Ulva armoricana was cultured at different salinities: 5, 10, 20, 25 and 35 ‰ (all ± 0.1 ‰) and nutrient treatments: 100 % Provasoli ES medium (high nutrient supply) and 0 % Provasoli ES medium (low nutrient supply) at 10 °C and 15 °C for 6 days under constant light (39.2 ± 0.43 μmol photons m⁻² s⁻¹) on a 16:8 hours light:dark photoperiod. Natural grazing (using Tricolia capensis Dunker) and artificial grazing (stimulated by scissors) was performed to determine their effects on the chemical composition of Ulva armoricana. Results obtained show that grazing and nutrient experiments mostly affected the aromatic, hydroxylic and carbonyl compounds regions, while salinity change mostly affected the alcohol, ester and phenolic regions. The aldehyde profiles included a prominent peak at δH 9.76 in almost all treatments that was provisionally identified as hexanal. Ulva armoricana grown at 10 °C under low nutrient condition and in a medium with salinity at 25 ‰ was found to be the ideal condition to produce a higher intensity of the main aldehyde.

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Teixeira, Ana Rute Soares. "Remoção simultânea de contaminantes inorgânicos em águas salinas pela macroalga viva Ulva lactuca." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21226.

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Mestrado em Química Este trabalho pretende contribuir para o desenvolvimento de metodologias alternativas para o tratamento de águas contaminadas. Para isso, investigou-se a capacidade de biossorção/biaccumulação da macroalga viva, Ulva lactuca, em águas salina e salobra contendo uma mistura de contaminantes inorgânicos: As, Cd, Pb, Cu, Cr, Hg, Mn e Ni. Os resultados obtidos evidenciaram que esta macroalga tem uma elevada capacidade de biorremoção, e que variações de salinidade (15-35) não afetam a eficiência do processo. As maiores reduções nos níveis de contaminantes em solução foram obtidos para 6 g/L de alga, em peso fresco. A percentagem de remoção variou entre 98% para o Hg e 48% para o As. Globalmente, o modelo de Elovich foi o que melhor descreveu a cinética do processo. O recurso a extrações com soluções de EDTA (0.001, 0.01 e 0.1 M) permitiu esclarecer que a maioria do Hg (~98%) e Cr (~80%) atravessaram as paredes da macroalga e os restantes elementos estudados (Mn, Ni, Cd, Cu, As e Pb) estavam retidos à superfície (entre 60 e 80%). A boa correlação entre os metais e o Mn nos extractos sugere uma associação entre estes elementos e os óxidos de Mn presumivelmente formados à superfície da macroalga. This work aims to contribute for the development of alternative methodologies of water remediation. For this, we investigated the biosorption/bioaccumulation capabilities of the living seaweed, Ulva lactuca, in salt and brackish waters, containing a mixture of inorganic contaminants: As, Cd, Pb, Cu, Cr, Hg, Mn and Ni. Results showed that the studied macroalga has a high bioremoval capacity, and that salinity variation (15-35) did not affect the efficiency of the process. The greatest reductions in the levels of contaminants in solution were obtained with 6 g/L of algae, in fresh weight. The removal percentages ranged from 48% for As to 98% for Hg. Overall, Elovich model was the best in describing the kinetics of the process. The use of extractions with EDTA (0.001, 0.01 to 0.1 M) has clarified that most of the Hg (~ 98%) and Cr (~ 80%) crossed the macroalgae walls, while the rest of the studied elements (Mn, Ni, cd, Cu, As and Pb) were retained at the surface (between 60 and 80%). The good correlation between metals and Mn in the extracts suggests an association between these elements and the oxides of Mn presumably formed on the surface of macroalgae.

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Al-Alam, Joséphine. "Polluants organiques : analyse, application au « biomonitoring » environnemental et introduction des biopesticides (algues marines) comme alternative." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF019.

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Dans un contexte où les inquiétudes environnementales dues à la pollution sont grandissantes à l’échelle globale, la surveillance de la pollution environnementale constitue un enjeu majeur de recherche afin de préserver au mieux un environnement sain et durable. En effet, la surveillance responsable et continue de l’environnement accompagnée par le développement d’alternatives de lutte « verte » contre les nuisibles, pourrait certainement ralentir voir inhiber la propagation de polluants néfastes pour l’ensemble de la biosphère. Dans ce contexte, les objectifs principaux de cette thèse visent d’une part à caractériser la qualité de l’air par une approche basée sur le biomonitoring, et d’autre part à développer un biopesticide d’origine algale permettant la protection des agrumes en post-récolte comme un exemple d’alternative à l’usage des traitements chimiques classiques. Pour répondre au premier objectif, des méthodes d’extraction multi résidus ont dû être développées. Ces méthodes ont été soit spécifiques d’une famille de pesticides tel que les dithiocarbamates, soit plus large et plus générale en considérant de nombreux polluants comme des pesticides, des HAPs et des PCBs. Ces dernières ont été basées soit sur l’ASE-SPE-SPME, soit sur le QuEChERS-SPME, et ont formé le socle des études de biosurveillance environnementale entreprises. Ces études de surveillance ont permis l’évaluation des modifications spatio-temporelles de la qualité de l’air grâce à des espèces naturelles ayant un rôle de capteurs biologique de la pollution environnementale et permettant par la suite l’estimation de la pollution dans des zones bien définies. Pour répondre au second objectif, des extraits aqueux d’algues vertes, Ulva linza et Ulva lactuca, ont été préparés et testés comme antifongiques in vivo et in vitro afin d’étudier leur aptitude à inhiber le développement de Penicillium digitatum sur des agrumes en post récolte. Un potentiel de protection des agrumes en poste-récolte contre ce champignon a été mis en évidence, donnant effectivement l’espoir à la fiabilité de cette approche comme alternative biologique pour le remplacement des pesticides chimiques potentiellement toxiques In a context where environmental concerns due to pollution are growing on a global scale, monitoring of environmental pollution is a major research challenge in order to preserve as much as possible a healthy and sustainable environment. Indeed, the responsible and continuous monitoring of the environment escorted by the development of "green" pest control alternatives could certainly decelerate or even inhibit the spread of harmful pollutants into the entire biosphere. In this context, the main objectives of this thesis are intended firstly to characterize air quality by a biomonitoring-based approach and, secondly, to develop a biopesticide of algal origin, that allows the protection of post-harvested citrus fruit, as an alternative to the use of conventional chemical treatments. In order to answer the first objective, multi-residues extraction methods were developed. These methods were either specific to a family of pesticides such as dithiocarbamates or wider and more general regarding numerous pollutants such as pesticides, PAHs and PCBs. The latter were based either on the ASE-SPE-SPME, or on the QuEChERS-SPME, and formed the base of environmental biomonitoring studies undertaken. These monitoring studies allowed the assessment of spatial and temporal changes in air quality through natural species acting as biological sensors of environmental pollution and subsequently allowing the estimation of pollution in well-defined areas. To answer the second objective aqueous extracts of green algae, Ulva linza and Ulva lactuca, were prepared and tested as in vivo and in vitro antifungal agents, in order to study their ability to inhibit the development of Penicillium digitatum on post-harvested citrus fruits. A potential of post-harvested citrus fruits’ protection against this fungus was proved, giving hope to the reliability of this approach as a biological alternative for the replacement of potentially toxic chemical pesticides

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Twigg, Matthew. "The signal based relationship between the green seaweed Ulva and its indigenous bacterial community." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13011/.

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This project has focused on the relationship between the green seaweed Ulva, commonly found in the intertidal zone of the UK coastline and its cognate bacterial community. It has previously been reported that motile Ulva zoospores are attracted to N-Acylhomoserine lactones (AHLs), signalling molecules utilised by Gram-negative bacteria in a density dependent form of cellular communication termed quorum sensing (QS) and produced by several biofilm dwelling species of marine bacteria. The species represented in the bacterial community associated with Ulva spp. were identified by generating a 16S rDNA phylogenetic clone library from bacterial DNA isolated from the surface of the seaweed. These data revealed that the majority of the population belonged to the Proteobacteria or Bacteroidetes phyla. In order to investigate whether QS signalling affected the rate of zoospore germination in addition to zoospore attraction, Ulva zoospores were settled and allowed to grow on synthetic AHLs, biofilms derived from AHL-producing model organisms and strains relevant to the Ulva epiphytic population which were shown to produce AHLs. Results from these experiments revealed that AHLs affected zoospore germination and the early growth of the Ulva germling as zoospores germinated and grown in the absence of AHLs were significantly longer than those germinated in the presence of AHLs. We therefore hypothesise that reduced germling growth in the presence of AHLs allows Ulva to obtain a healthy epiphytic bacterial community that is vital for the seaweed’s later development. Further understanding of Ulva growth biology could have potential applications in preventing marine biofouling by this genus of seaweed. This study progressed to characterise AHL production in a number of strains of Shewanella and Bacteroidetes bacteria, which, for differing reasons were deemed relevant to Ulva biology. Although data presented by this thesis showed AHL production in these bacterial groups, AHL synthase and response regulator sequences could not be identified in the published genome sequences from either Shewanella or the Bacteroidetes. This study also identified an AHL inactivating acylase enzyme in an environmental Shewanella isolate. This acylase, AacS, was shown to degrade a variety of synthetic AHLs and the AHLs produced by Yersinia pseudotuberculosis. This study has therefore increased the range of marine bacteria known to be producing AHLs, however the lack of AHL synthase and response regulator genes in the genomes of these bacteria leads to the conclusion that many marine bacteria possess novel, yet to be characterised AHL-mediated QS systems. Finally, this study screened a number of extracts from marine microalgae for compounds that act as agonists or antagonists to AHL-mediated QS. Although no AHL mimics were identified data presented by this thesis showed extracts to affect the luminescence produced in lux-based AHL bio-reporters in the presence of exogenously added signal, affect a number of QS regulated phenotypes in marine pathogens and effect QS regulated genes in the human pathogen Pseudomonas aeruginosa. As such, we hypothesise that these microalgae have the ability to produce quorum-quenching compound(s). Further characterisation of quorum-quenching compound(s) produced by microalgae may be beneficial in the bio-control of pathogenic bacteria in aquaculture and may act as candidates for novel antibiotics.

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Fontoura, Mariane Pallaoro da. "Avaliação da macroalga Ulva lactuca como co-alimento para o camarão branco do Pacífico." reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/133217.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aqüicultura, Florianópolis, 2015. Made available in DSpace on 2015-06-02T04:07:55Z (GMT). No. of bitstreams: 1 333972.pdf: 547655 bytes, checksum: 0e564adaa0c8f10feee9fd4bf6ef3fb0 (MD5) Previous issue date: 2015 O objetivo deste estudo foi avaliar o desempenho do camarão Litopenaeus vannamei quando co-alimentado com macroalga Ulva lactuca em diferentes níveis de substituição (25, 50, 75, 100%) de ração comercial. O experimento foi conduzido durante 28 dias, em caixas plásticas com 30L de volume útil, aeração constante, temperatura de 26± 2°C, salinidade de 35 ? e renovação diária de 80%. Cada unidade experimental foi povoada com 10 camarões (3,7± 0,2 g), sendo os tratamentos com diferentes níveis de substituição da ração pela macroalga foram feitos em triplicata. Como controle, foi utilizada alimentação sem substituição por macroalgas. A biomassa algácea in natura foi ofertada de acordo com cada tratamento e permaneciam disponíveis para os camarões por 24 horas. A dieta comercial foi fornecido três vezes ao dia, calculado de acordo com 5% da biomassa inicial de cada tanque e tratamento. Foi observada uma tendência linear negativa para peso final, ganho em peso semanal e total, e taxa de crescimento do camarão com o aumento da substituição da ração pela macroalga. No entanto, com nível de substituição até 50% o desempenho dos camarões não foi afetado significativamente. A sobrevivência foi acima de 86% até 75% de substituição, e no tratamento com 100% de substituição foi significativamente diferente dos demais tratamentos (p<0,05), com 16,7%. Os resultados indicam que a utilização da ração comercial pode ser substituída em até 50%, resultando em baixo custo de produção e possível melhoria na qualidade água, sem prejudicar o crescimento do camarão marinho Litopenaeus vannamei em sistema de cultivo em água clara.

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Paulert, Roberta. "Atividade antimicrobiana e controle da antracnose do feijoeiro comum (Phaseolus vulgaris L.) utilizando polissacarídeo e extratos de macroalga marinha Ulva fasciata." Florianópolis, SC, 2005. http://repositorio.ufsc.br/handle/123456789/101868.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina. Programa de Pós-Graduação em Biotecnologia. Made available in DSpace on 2013-07-15T23:25:42Z (GMT). No. of bitstreams: 1 224306.pdf: 1144206 bytes, checksum: 3851e6455c9e7fcbff5c43c79ee99f3c (MD5) Compostos presentes em algas marinhas podem desempenhar importantes funções biológicas, entre elas: atividade antimicrobiana direta, influenciando as interações entre planta-patógeno ou ativando mecanismos de defesa das plantas tratadas. O polissacarídeo ulvana, os extratos solúvel e insolúvel em metanol, o extrato etanólico obtidos de Ulva fasciata e o polissacarídeo B obtido de Ulva sp. foram testados quanto a atividade antimicrobiana e o potencial desta macroalga marinha no controle da antracnose de feijoeiro comum, causada pelo fungo Colletotrichum lindemuthianum. Para a obtenção da ulvana, algas frescas foram autoclavadas com água destilada; a solução resultante foi filtrada e precipitada com etanol. O polissacarídeo foi identificado por RNM-1H e RNM-13C e I.V. como unidades repetitivas de ácido ulvanobiurônico-3-sulfato. Para a obtenção dos extratos metanólicos e do extrato etanólico, algas secas e moídas foram extraídas com metanol em sistema de soxhlet ou com etanol, respectivamente. A atividade antimicrobiana da ulvana e dos extratos metanólicos foi determinada pelo método de difusão em ágar frente a bactérias potencialmente patogênicas ao homem: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus, Micrococcus luteus, a levedura Candida albicans e bactérias fitopatogênicas: Xanthomonas campestris e Erwinia carotovora. A concentração inibitória mínima, através do método de microdiluição em caldo, foi determinada contra os fungos: C. lindemuthianum (fitopatogênico), Trichophyton mentagrophytes e Microsporum canis (dermatófitos). Além disto, o efeito da ulvana e dos extratos metanólicos foi avaliado, in vitro, nos testes de inibição de crescimento miceliano e inibição da germinação de conídios de C. lindemuthianum. In vivo, foi avaliado o efeito do extrato etanólico, extratos metanólicos, ulvana e polissacarídeo B na proteção de plantas de feijão comum (Phaseolus vulgaris L.) contra antracnose em casa-de-vegetação. Os resultados demonstraram que os extratos metanólicos inibiram o crescimento de bactérias Gram-negativas: P. aeruginosa, X. campestris e E. carotovora. Além disso, o extrato insolúvel (2 mg/ml) em metanol inibiu o crescimento de T. mentagrophytes e o extrato solúvel em metanol (1 e 2 mg/ml) inibiu significativamente (p<0,05) o crescimento miceliano de C. lindemuthianum. Por outro lado, nenhum dos extratos testados inibiu a germinação dos conídios deste fungo e a ulvana não apresentou nenhuma atividade in vitro contra os microrganismos testados. Nos experimentos in vivo, observou-se que o extrato etanólico (10 mg de alga seca/ml) e a ulvana (10 mg/ml) de U. fasciata apresentaram uma possível indução de resistência quando pulverizados três dias e quatro dias antes da inoculação do fungo, respectivamente.

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De, Bruin Franklin Quelain. "Carbon-carbon coupling reactions catalysed by palladium nanoparticles supported on the green alga Ulva armoricana." University of Western Cape, 2018. http://hdl.handle.net/11394/6076.

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Magister Scientiae - MSc (Chemistry) The synthesis of nanomaterials, especially metallic nanoparticles, has attracted an enormous amount of interest over the past decade. They exhibit unique properties that allow the multiple applications in a variety of fields in science and technology. Their applications are limited by the efficiency and control of their synthesis to produce nanoparticles of certain size and shape. With ever mounting concern for the environment, a great amount of research has recently been extended to synthetic procedures that are carried out with limited or no toxicity to human health and the environment. One method involves the use of biological (or biogenic) materials for nanoparticle synthesis. This method is particularly attractive due to the fact that it is a relatively cheap, simple and environmentally friendly method compared to that of conventional chemical methods of synthesis.

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Hodder, Janet. "Production biology of an estuarine population of the green algae, Ulva spp. in Coos Bay, Oregon." Thesis, University of Oregon, 1986. http://hdl.handle.net/1794/9425.

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x, 106 leaves : ill., maps ; 29 cm Notes Typescript Thesis (Ph. D.)--University of Oregon, 1986 Includes vita and abstract Bibliography: leaves 98-106 Another copy on microfilm is located in Archives

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Zehlila, Amel. "Caractérisation structurale et fonctionnelle des métabolites de l'algue verte Ulva Rigida au moyen d'une approche protéomique." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR101/document.

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Les molécules naturelles de différentes origines et essentiellement celles issues des algues marines conçoivent une panoplie de principes bioactifs naturels à fort potentiel thérapeutique. Actuellement, plusieurs recherches sont consacrées à l’isolement de nouveaux composés bioactifs à partir des ressources marines qui renferment des effets bénéfiques prometteurs pour la santé. Parmi les ressources marines, les composés bioactifs présents dans de nombreuses espèces d’algues ont des propriétés nutritionnelles et pharmaceutiques particulièrement intéressantes. Cette thèse s’intéresse aux effets bénéfiques de l’algue Ulva rigida. Elle concerne plus particulièrement les activités des extraits protéiques de l’algue verte Ulva rigida. En effet, dans la présente étude, nous avons étudié l'effet préventif d'un extrait de protéine (PE) d'Ulva rigida contre les dommages cellulaires induits par les UVB. Nous avons démontré qu'un traitement des astrocytes corticaux avec 50 μg de PE induit un fort effet glioprotecteur et supprime les effets nocifs des rayonnements UVB, augmentant en particulier la viabilité cellulaire. D’autres essais supplémentaires nous ont permis d’affirmer que cet extrait stimule l'activité de la catalase et de la superoxyde dismutase et inhibe la production de marqueurs de stress, tels que le H2O2 ou la peroxydation lipidique. Par ailleurs, la digestion protéolytique ou le traitement thermique de l'extrait d'algue ont inhibé cet effet préventif, plaidant pour le rôle prédominant de la fraction protéique. Par la suite, des études protéomiques ont permis d'identifier plusieurs protéines de l'extrait, parmi lesquelles la calmoduline s'est avérée représenter un contributeur important aux activités de protection observées à la fois sur des cultures d’astrocytes que sur des neurones en grain Natural molecules from different origins present a high therapeutic potential. Among them, molecules extracted from marine algae are particularly interesting. Several studies are currently being devoted to the isolation of new bioactive compounds from marine resources that have promising health benefits. Among the marine resources, the bioactive compounds present in many species of algae have particularly interesting nutritional and pharmaceutical properties. This thesis deals with the beneficial effects of the alga Ulva rigida. It relates more particularly to the activities of the protein extract of the green alga Ulva rigida. In this study, we studied the preventive effect of a protein extract (PE) of Ulva rigida against UVB-induced cell damage. We have demonstrated that treatment of cortical astrocytes with 50 μg of PE induces a strong glioprotective effect and suppresses the harmful effects of UVB radiation, in particular increasing cell viability. Other extra tests allowed us to say that this extract stimulates the activity of catalase and superoxide dismutase and inhibits the production of stress markers such as H2O2 or lipid peroxidation. Moreover, the proteolytic digestion or the heat treatment of the algal extract inhibited this preventive effect, arguing for the predominant role of the protein fraction. Subsequently, proteomic studies have identified several proteins in the extract, of which calmodulin has been shown to be an important contributor to the protective activities observed on both astrocyte and neuron cultures

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Hone, Patrick William. "The interaction between water movement, diffusion boundary layers, phosphate uptake and phosphate limited growth of Ulva australis /." Title page, contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phh7722.pdf.

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Hana, Kucera. "Species identification and discovery in common marine macroalgae: Fucus, Porphyra and Ulva using a DNA barcoding approach." Thesis, University of New Brunswick, 2010. http://hdl.handle.net/1882/1090.

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The oceans represent a wealth of biological diversity where many species remain to be discovered and described. Among seaweeds, a paucity of morphological features by which to differentiate species means that many genera harbour overlooked or cryptic species. Fucus, Porphyra and Ulva are three common genera of marine intertidal algae and all include species that are particularly difficult to distinguish morphologically. DNA barcoding has been championed as a revolutionary tool for species identification and discovery and applying this tool to algae was a logical step due to the difficulty of morphological identification of many algal species. This thesis is part of a significant initiative aimed at identification and discovery of all species of seaweeds in Canadian waters, using a DNA barcoding approach. The original concept of DNA barcoding relied on comparing the 5’ region of the mitochondrial cytochrome c oxidase 1 (COI-5P) gene among animal species. In this study, DNA barcoding with COI-5P was applied to the brown algal genus Fucus and worked as well as any other marker to assign morphologies to known species. The DNA barcoding results also uncovered substantial phenotypic diversity in Pacific F. distichus. Results were confirmed by comparison with sequences of the nuclear internal transcribed spacer region (ITS). For Porphyra, COI-5P DNA barcoding was compared with species identification using the chloroplast large rubisco subunit (rbcL) and the Universal Plastid Amplicon (UPA) in a floristic survey of Canadian Porphyra species. Two new species were discovered and described (Porphyra corallicola and Porphyra peggicovensis), and P. cuneiformis was synonymized with P. amplissima. The COI-5P emerged as the best marker for species discrimination despite difficulties with primer universality. To aid in choosing a marker for DNA barcoding for green algae, the universality and species discriminatory power of the rubisco large subunit (rbcL) (considering the 5’ and 3’ fragments independently), the UPA, the D2/D3 region of the nuclear large ribosomal subunit (LSU-D2/D3) and the ITS were evaluated. While the rbcL-3P highlighted several cryptic species, and worked well to distinguish Ulva species, more research is needed to recommend a marker for DNA barcoding generally in marine green macroalgae.

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Robertson-Andersson, Deborah. "Biological and economical feasibility studies of using seaweeds Ulva lactuca (Chlorophyta) in recirculation systems in abalone farming." Doctoral thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/6174.

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Includes bibliographical references (p. 282-311). The aim of this study was to investigate whether a land-based recirculating seaweed-abalone integrated aquaculture system using Ulva lactuca was feasible as well as to test the differences between a commercial gravel bed recirculation system to an existing flow through system. These studies were carried out at two abalone farms: Danger Point (I & J) (140 km east of Cape Town) and at Jacobs Bay (JSP) (120 km north of Cape Town. South Africa). In both studies no significant difference in terms of water quality, abalone growth rates and abalone health were found. It was found that a seaweed /abalone recirculating system at the designed water exchange rates (25 %) was nitrogen limited and that the system as designed could be run at 75 % recirculation rate and remove a significant proportion of the dissolved nutrients (ammonium, phosphorus, nitrate and nitrite).

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Huang, Xiao Hang. "Etude du trafic membranaire chez les algues marines : les vesicules mantelees de laminaria digitata et ulva lactuca." Paris 5, 1988. http://www.theses.fr/1988PA05S006.

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Nous avons, pour la premiere fois, isole et caracterise les vesicules mantelees a partir d'algues marines: laminaria digitata et ulva lactuca representantes des algues brunes et des algues vertes respectivement. Les fractions enrichies en vesicules mantelees ont ete preparees par gradient discontinu de saccharose. Les polypeptides de 170-175 kda correspondent aux chaines lourdes de la clathrine de buf et un des polypeptides de 70 kda est semblable au composant de la clathrine de carotte. Tous ces polypeptides montrent une reponse positive a l'anticorps anticlathrine de buf obtenu chez la chevre ou chez le lapin. Chez u. Lactuca, la proportion de la clathrine varie pendant les etapes de croissance de la plante. Les images de microscopie electronique revelent une structure reguliere du manteau vesiculaire. L'analyse lipidique montre la presence des phospholipides dans les vm de ces algues. L'analyse des glucides montre une proportion elevee de galnac et glcnac dans les vm, alors qu'ils ne sont pas detectables dans les extraits totaux de ces algues. La composition chimique des vesicules mantelees, quantitativement specifique pour chaque type d'algue etudie, suggere l'implication des vesicules mantelees dans l'edification des parois cellulaires ainsi que dans le transport des glycoproteines et glycolipides vers les differentes membranes cellulaires

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Freitas, Mateus Brusco de. "Mecanismos de resistência e eficiência de formulações de ulvana no controle da antracnose (Colletotrichum lindemuthianum) do feijoeiro (Phaseolus vulgaris L.)." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93580.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, 2010 Made available in DSpace on 2012-10-25T00:28:43Z (GMT). No. of bitstreams: 1 274975.pdf: 809433 bytes, checksum: b63aa5f59469f013c937206b22f4bf42 (MD5) O presente trabalho teve por objetivo avaliar os mecanismos de defesa bioquímicos e histológicos envolvidos na resistência inata do feijoeiro à antracnose, compará-los com aqueles induzidos pela aplicação foliar de ulvana e avaliar o efeito de inertes na armazenabilidade e eficiência da ulvana. Para a avaliação dos mecanismos de defesa, plantas resistentes e suscetíveis de P. vulgaris cv. Uirapuru foram tratadas, 6 e 3 dias antes da inoculação (DAI), com água (testemunha) ou ulvana (10mg/mL) e inoculadas com C. lindemuthianum no estádio fenológico V4. A severidade da antracnose foi avaliada em intervalos de 2 dias. As atividades de peroxidases e glucanases foram determinadas às 12, 24 e 48 horas após a inoculação (HAI) em folíolos do primeiro trifólio. A germinação de conídios, formação de apressórios de C. lindemuhianum e a reação de hipersensibilidade (RH) em plantas de P. vulgaris foram avaliadas às 12, 24 e 48 HAI em discos foliares retirados do primeiro trifólio. Para a avaliação do efeito de diferentes inertes, foram realizados quatro experimentos idênticos durante o período de 1 ano. Para tanto, plantas de P. vulgaris cv. Uirapuru foram tratadas, 6 e 3 DAI, com água destilada ou ulvana (10mg/mL) (testemunhas) ou com as formulações de ulvana com os inertes caulinita, sílica amorfa e atapulgita e inoculadas com C. lindemuthianum no estádio fenológico V4. Plantas resistentes não apresentaram sintomas da antracnose, sendo que, 4 DPI foram visualizados pequenos pontos necróticos caracterizando a RH. O efeito local da ulvana foi mais evidente que o sistêmico. A atividade de POX foi sempre maior em plantas resistentes, mas a atividade de GLU foi similar. A pulverização de ulvana elevou a atividade de POX e GLU tanto em plantas inoculadas quanto em não inoculadas. A germinação e a formação de apressórios do fungo não foram alteradas pela resistência inata ou pela aplicação de ulvana. O número de células hipersensitivas foi maior em plantas resistentes e menor em plantas tratadas com ulvana, quando comparadas com os respectivos controles. A eficiência da ulvana foi reduzida pela formulação contendo atapulgita, mas não pela que continha sílica amorfa ou caulinita.

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Mukhoro, Ofhani Christopher. "Green Synthesis and characterization of gold Nanoparticles using Green Alga Ulva Lactuca and evaluation of their Catalytric Role." University of the Western Cape, 2016. http://hdl.handle.net/11394/6078.

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Magister Scientiae - MSc (Biotechnology) Nanoparticles synthesized using typical chemical procedures have associated environmental risks because of the use of hazardous chemicals. With the ever-increasing potential application for nanomaterials, there is a growing need to develop new synthetic procedures for nanomaterials which are non-toxic and eco-friendly. This study presents, as a first step, the screening of the aqueous extracts of several seaweeds in order to assess their ability to produce gold nanoparticles (AuNPs). Eleven aqueous extracts were screened for the synthesis of AuNPs and where AuNPs were formed, these were further characterized using UV-vis spectroscopy and HRTEM primarily. Three of the eleven aqueous extracts shown to produce AuNPs were extracts obtained from brown algae. The total antioxidant and total reducing power contents, as well as the DPPH radical scavenging abilities for these extracts were determined and related to their ability to produce the NPs. The AuNPs were found to be of various shapes and sizes including spheres, rods and triangles, with sizes ranging from 20 nm to 200 nm.

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Kandjengo, Lineekela. "The effects of temperature and light on three South African Ulva species,and their potential in integrated aquaculture." Thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/26639.

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Kandjengo, Lineekela. "The molecular systematics of Ulva Linnaeus and Enteromorpha Link (Ulvales, Chlorophyta) from the South Western Cape, South Africa." Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/6108.

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Bibliography : leaves 64-79. Both Ulva and Enteromorpha are very common, ubiquitous, and environmentally important genera of green seaweeds. The evolutionary history of Ulva species is poorly understood, stemming from a lack of diagnostic, non-molecular systematic characters. This study addresses the following questions: i) Do the two genera represent distinct entitiesj ii) What are the relationships among local putative species; iii) Do the recognized species represent monophyletic lineages; iv) How closely are local species related to those from elsewhere? These questions are addressed using nuclear ribosomal DNA ITS sequences from 48 local samples plus data on 16 samples from GenBank.

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Circuncisão, Ana Rita Sousa. "Análise do perfil nutricional de Ulva rigida cultivada sob diferentes condições em sistema de aquacultura integrada multi-trófica." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22891.

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Mestrado em Bioquímica - Bioquímica Alimentar Recentemente, tem surgido um elevado interesse na utilização comercial das macroalgas, sobretudo no setor alimentar, devido aos seus constituintes que na maioria exibem múltiplas bioatividades benéficas para a saúde. A Ulva rigida é uma macroalga verde, cosmopolita, capaz de se adaptar a uma vasta gama de condições ambientais, tornando a sua reprodução possível ao longo de todo o ano. Desta forma, torna-se uma espécie promissora de ser integrada num sistema de IMTA (aquacultura integrada multi-trófica) onde geralmente ocorre a manipulação de condições de cultivo com vista à alteração do valor nutricional das macroalgas. Neste contexto, o objetivo deste trabalho consistiu na avaliação de diferentes parâmetros nutricionais na Ulva rigida cultivada sob diferentes condições em dois desenhos experimentais diferentes, em sistema de IMTA. Para o primeiro desenho experimental, foram estabelecidas diferentes Densidades de Cultivo (DC) e Taxas de Renovação do meio de cultivo (TR) avaliadas em dois períodos sazonais diferentes. Os resultados permitiram concluir que a DC influenciou positivamente o teor de cinzas entre as diferentes condições atingindo na condição com menor DC e TR cerca de 38 % bs (base seca) em setembro. Analogamente, o teor de proteína foi influenciado pela TR, verificando um aumento do teor de médio deste parâmetro de setembro para janeiro (atingindo os 23,5 % bs) devido à maior disponibilidade de nutrientes no meio de cultivo induzido pela maior TR e pela sazonalidade. Para o segundo desenho experimental, foram estabelecidas diferentes DC e utilizados dois tipos de água de cultivo (nova e velha) de modo a avaliar, principalmente, o perfil de hidratos de carbono da Ulva rigida ao longo de três semanas. Os resultados evidenciaram que as condições de cultivo não influenciaram o teor de humidade, resíduo sólido e cinzas, no entanto foi registado uma diminuição do teor de proteína (de 18 para 7% bs), para as diferentes condições, ao longo do tempo. Em contrapartida, a análise de açúcares realizada ao Resíduo Insolúvel em Álcool (AIR) evidenciou que a Ulva rigida é constituída por Rha (7-8 % m/m), Xyl (2-3 % m/m) e UA (ácidos urónicos) (18-23% m/m), associados à presença de ulvanas, que se mantêm, praticamente inalterados entre as diferentes condições, ao longo do tempo. Contudo, foi verificado um aumento do teor de Glc (10-27 % m/m), da razão Glc/Rha e do teor total polissacarídeos do AIR, entre as diferentes condições de cultivo, ao longo do tempo, associado possivelmente à presença de amido. Adicionalmente, foram estudadas as ligações glicosídicas presentes num extrato de ulvanas, com vista à identificação da posição dos grupos sulfato tendo-se verificado, por dessulfatação, o aumento da ligação 4-Xyl e da 3,4-Rha, possivelmente indicativas da di-substituição por sulfatos no C-2 e C-3 da Xyl e Rha, estando esta última especialmente sulfatada no C-2. Assim, este trabalho permitiu concluir que a manipulação de diferentes condições de cultivo num sistema de IMTA pode induzir alterações especificas na composição físico-química da Ulva rigida, melhorando o seu valor nutricional e rentabilidade no mercado. Recently, there has been an increasing interest in the commercial use of seaweeds, mainly in the food industry, due to their chemical compounds, which can exhibit multiple bioative health effects. The Ulva rigida is a green macroalgae, cosmopolitan, and its tolerance to a high range of environmental conditons making reproduction possible throughout the year. Thus, this is a promising specie to be integrated in the IMTA (Integrated Multi-Trophic Aquaculture) system, where the modulation of growth conditions are established in order to change the nutritional value of macroalgae. In this context, the aim of this work consisted in the evaluation of different nutritional parameters in Ulva rigida, cultivated under different conditions in two different experimental designs in an IMTA system. For the first experimental design, different stocking density (SD) and nutrient flow rate (NFR) were evaluated in two different seasonal periods. By this way, it was observed that the stocking density positively influenced the ash content between the different conditions, reaching about 38 % DM (dry matter) in september under the condition with lower DC and NFR. Similarly, the protein content was influenced by nutrient flow rate observed by an increase in the mean content of this parameter from September to January (reaching about 23,5 % DM), mainly due to the higher availability of nutrients in the medium, induced by the higher nutrient flow rate and seasonality. For the second experimental design, different SD and water types were implemented in order to mainly evaluate the carbohydrate profile of Ulva rigida over three weeks. The results showed that the cultivation conditions did not influence the moisture content, solid residue and ashes, however, a decrease of the protein content (from 18 to 7 % DM) was observed over time for the different conditions. In contrast, the sugar analysis performed on the AIR showed that the Ulva rigida was composed by Rha (7-8% m/m), Xyl (2-3 % m/m) and UA (18-23% m/m), associated to the presence of ulvans, which remained practically unchanged between the different conditions over time. However, an increase in the content of Glc (10-27 % m/m), Glc/Rha ratio and total AIR Polysaccharides, among the different conditions, over time, it was associated to the presence of starch. In addition, the glycosidic linkages present in an ulvans’s extraxt were studied in order to identify the position of the sulfate groups. The increase of the 4-Xyl and 3,4-Rha linkages indicate the existence of di-substitution by sulfates at C-2 and C-3 of Xyl and Rha, the later being speacially sulfated at C-2. Thus, the manipulation of different cultivation conditions in an IMTA system induced a change in the physical-chemical composition of Ulva rigida, improving not only its nutritional value but also its profitability in the market.

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Pinheiro, Valentina Alexandra Francisco Alves. "Avaliação de alterações físico-químicas das algas Gracilaria sp. e Ulva rigida sujeitas a diferentes tratamentos de conservação." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22765.

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Mestrado em Biotecnologia Alimentar A alga verde Ulva rigida e a alga vermelha Gracilaria sp. são algas edíveis e constituem uma fonte rica de nutrientes. No entanto, devido à sua elevada humidade, são um alimento muito perecível e por isso muitas vezes sujeitas a processamentos como forma de aumentar o seu tempo de prateleira. Neste contexto, este trabalho pretendeu avaliar o impacto de processamento de secagem a 25 ºC, salmoura e salga (28 e 40%) nas alterações físico-químicas de U. rigida e G. sp., considerando o seu tempo de armazenamento. Mais especificamente, as alterações de textura e/ou cor superficial foram registadas logo após o tratamento (t0), aos 30, 60, 120 e 180 dias, no caso da U. rigida, ou 30 e 60 dias, para a alga G. sp. Em adição, os parâmetros químicos (cinza, gordura, ácidos gordos, proteína, fibra dietética e pigmentos) foram determinados em t0 e no final do ensaio experimental (t180 e t60 para U. rigida e G. sp., respetivamente). Relativamente à cor superficial da U. rigida, foi possível verificar que ao longo dos 180 dias, a alga perdeu a sua tonalidade verde e intensificou o tom de amarelo e a sua luminosidade, em todas as condições de conservação. A fraturabilidade desta macroalga em t0 era superior quando sujeita a desidratação (2,44 N), em relação às algas com tratamento salino (1,3-2,1N) e, este parâmetro também sofreu um aumento significativo ao longo do tempo de armazenamento, em todas as amostras de U. rigida. Em relação aos parâmetros químicos, os resultados obtidos indicaram valores de % relativa de humidade de 14-15% b.s. em U. rigida desidratada e valores na gama de 60-70% b.s. para as algas sujeitas a tratamento salino. A % de cinza de U. rigida foi superior nas algas sujeitas a salga (atingindo valores de 21,1% b.s. na alga em salga 40%), diminuindo no entanto ao longo dos 180 dias. A fração lipídica recuperada da U. rigida desidratada (1,19% b.s.) em t0 foi consideravelmente superior à das outras condições de tratamento, tendo no entanto diminuído significativamente em t180. A redução de rendimento de extrato lipídico em t180 relativamente a t0 foi igualmente observado para as algas em salmoura, mas um comportamento oposto foi registado nas algas sujeitas a salga seca, cuja fração lipídica representava 0,49% b.s. e 0,41% b.s. em t0 e 0,65% b.s. e 0,54% b.s. em t180 (salga 28% e 40%, respetivamente). No geral, a concentração de ácidos gordos seguiu uma tendência semelhante à da recuperação da fração lipídica, permitindo sugerir que parte das diferenças neste último parâmetro poderão ser devidas a alteração de concentração dos níveis de ácidos gordos. Por outro lado, os níveis proteicos em U. rigida mantiveram-se constantes ao longo do tempo e entre condições de conservação, apresentando valores de 24-25% b.s. Já a % de fibra de U. rigida variou entre 40 e 60% b.s., manifestando maior % de fibra insolúvel que fibra solúvel aos 0 dias. Os pigmentos identificados em U. rigida foram as clorofilas (a e b) e feofitina a, que atingiram valores de aproximadamente 4 μg/mg b.s., e carotenoides (aprox. 0,7 μg/mg b.s.). Variações nos níveis destes pigmentos durante o tempo de armazenamento foram principalmente registados nas algas tratadas com salga seca. A cor superficial da G. sp. apresentou diminuição dos tons vermelho, amarelo e também da sua luminosidade, excetuando a alga em salmoura que contrariou estas tendências. Em relação aos parâmetros químicos, os resultados obtidos indicaram valores de % relativa de humidade de 7-9% b.s. para a alga desidratada e valores na gama de 60-70% b.s. para as algas sujeitas a tratamento salino. A % de cinza de G. sp atingiu valores de 26,6% b.s. em salga 28%, tendo-se verificado uma diminuição significativa de cinza nas salgas secas. A % de proteína manteve-se constante ao longo do tempo e entre condições de conservação em G. sp., apresentando valores de aproximadamente 25%. Em G. sp. apenas clorofila a e feorbidina a (1,2-0,2 μg/mg b.s.) foram identificados The green seaweed Ulva rigida and the red seaweed Gracilaria sp. are edible algae and constitute a rich source of nutrients. However, due to their high humidity, they are a very perishable food and therefore often subjected to processing, in order to increase their shelf life. In this context, the objective of this work was to evaluate the impact of the drying treatment at 25°C, brining and salting (28 and 40%) on the physical-chemical characteristics of U. rigida and G. sp., considering its storage time. More specifically, changes in texture and/or surface color were recorded right after the application of the processing treatment (t0), or after 30, 60, 120 and 180 days in the case of U. rigida, or 30 and 60, for G. sp. In addition, the chemical parameters (ash, fat, fatty acids, protein, dietary fiber and pigments) were determined at t0 and at the end of the experimental assay (t180 and t60 for U. rigida and G. sp., respectively). Regarding the surface color of U. rigida, it was possible to verify that during the 180 days, the algae lost its green tone, while the yellow tone and luminosity were intensified, under all conditions of conservation. The fracturability of this macroalgae at t0 was higher when subjected to dehydration (2.44 N), in comparison to saline-treated algae (1.3-2.1 N), and this parameter also increased significantly over the storage time, in all U. rigida samples. Regarding the chemical parameters, moisture values for dehydrated U. rigida were 14-15% d.w., while those of saline-treated algae ranged in between 60-70% d.w.. The ash content of U. rigida was higher in the salting-treated algae (reaching values of 21.1% d.w. in the algae in 40% salting), decreasing, however, along the 180 days. The lipid fraction recovered from dehydrated U. rigida (1.19% d.w.) at t0 was considerably higher than those of the remaining treatments. However, this yield was significantly decreased in t180. The decrement in the yield of lipid extract at t180 relative to t0 was also observed for brined algae, but an opposite behavior was registered for dry-salting treated algae, whose lipid fraction represented 0.49% d.w. and 0.41% d.w. in t0 and 0.65% d.w. and 0.54% d.w. in t180 (salting 28% and 40%, respectively). In general, the fatty acid concentration followed a similar trend to that of the recovery of the lipid fraction, suggesting that part of the differences in the latter parameter are due to changes in the fatty acid levels. On the other hand, protein content in U. rigida remained constant over time and between storage conditions, presenting values of 24-25% d.w. The % of U. rigida fiber varied between 40 and 60% d.w., showing a higher percentage of insoluble fiber than soluble fiber at 0 days. The pigments identified in U. rigida comprised chlorophylls (a and b) and pheophytin a, which reached values of approximately 4 μg/mg d.w., and carotenoids (approximately 0.7 μg/mg d.w.). Variations in the levels of these pigments during storage time were mainly recorded dry salting algae. The surface color for G. sp. showed a decrease of its red and yellow tones and well as of its luminosity, excepting for the treated-brined seaweeds that contradicted these tendencies. Regarding the chemical parameters, moisture values of 7-9% d.w. were registered for dehydrated algae, while those of saline-treated algae were in the range of 60-70% d.w. The ash % of G. sp reached values of 26.6% d.w. in salting 28% condition, and there was a significant decrease of ash in dry salting. The % of protein was maintained over time and between storage conditions in G. sp., presenting values of approximately 25% d.w. In G. sp. only chlorophyll a and feorbidin a (1.2-0.2 μg/mg d.w.) were identified

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Pilatti, Fernanda Kokowicz. "Ultraestrutura, bioquímica e fingerprint metabólico de Ulva lactuca Linnaeus (Chlorophyta) após exposição aguda ao diesel e à gasolina." reponame:Repositório Institucional da UFSC, 2016. https://repositorio.ufsc.br/xmlui/handle/123456789/174891.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Florianópolis, 2016. Made available in DSpace on 2017-04-18T04:12:49Z (GMT). No. of bitstreams: 1 344486.pdf: 18193868 bytes, checksum: 7ecbdb40a13855e053a7f241ef18cf0c (MD5) Previous issue date: 2016 Os combustíveis fósseis são responsáveis por uma fração considerável da poluição que atinge os ecossistemas marinhos, sendo a gasolina e o óleo diesel são os mais consumidos no mundo. As macroalgas possuem grande importância ecológica em muitos ecossistemas marinhos, porém poucas pesquisas têm sido realizadas objetivando elucidar os efeitos de hidrocarbonetos derivados do petróleo sobre estes organismos, em comparação ao número de publicações que utilizam microalgas, invertebrados e vertebrados como objeto de estudo. Ulva lactuca (Chlorophyta) foi escolhida como modelo biológico neste estudo por ser uma espécie cosmopolita, conhecida por sua tolerância a ambientes impactados por efluentes domésticos e industriais e capacidade de bioacumular metais pesados. Os efeitos do óleo diesel e da gasolina, em combinações de concentrações (0,001%, 0,01%, 0,1%, 1,0%) e tempo de exposição (30 min, 1 h, 12 h, 24 h), foram investigados sobre a ultraestrutura, bioquímica e metabolômica de U. lactuca. A microscopia eletrônica de varredura (MEV) revelou que 1 h de exposição ao óleo diesel e à gasolina já é suficiente para provocar alterações drásticas na mucilagem dos talos, um efeito que se mantém após 12 h e 24 h de exposição. Com a análise citoquímica com Azul Brilhante de Coomassie (CBB) observou-se que a exposição à gasolina provoca desorganização e aglutinação da porção proteica citoplasmática, possivelmente atingindo sistemas enzimáticos das membranas das organelas, um efeito menos intenso nos talos expostos ao diesel. Flutuações nos conteúdos de clorofilas a e b e no perfil de carotenoides foram detectadas em talos expostos ao óleo diesel, embora tais diferenças não foram relacionadas à concentração do combustível ou ao tempo de exposição. A exposição ao diesel também causou redução no conteúdo de polifenóis em relação ao grupo controle e aumento dos conteúdos de açúcares solúveis e de amido, principalmente após 12 h. Talos expostos à gasolina também apresentaram alterações nos conteúdos de clorofilas a e b. Constatou-se que a redução dos teores de carotenóides e de polifenóis, e o aumento dos conteúdos de açúcares solúveis e de amido é função direta em relação ao tempo de exposição a este combustível. O conjunto de resultados obtidos por MEV, citoquímica e bioquímica indica que a exposição aguda de U. lactuca à gasolina causa danos mais intensos à estrutura celular do que a exposição ao diesel, possivelmente devido à alta permeabilidade dos hidrocarbonetos aromáticos e do etanol presentes na gasolina brasileira. Adicionalmente, verificou-se que os pigmentos fotossintetizantes e suas rotas biossintéticas são menos suscetíveis às agressões dos combustíveis. O aumento dos teores de açúcares solúveis e de amido nos talos expostos aos xenobióticos sugere que os hidrocarbonetos podem ser metabolizados via Ciclo do Ácido Cítrico, conferindo a esta espécie um papel importante desta espécie na biorremediação dos ecossistemas. Ademais, especula-se que os conteúdos de polifenóis, açúcares solúveis, amido, associados à citoquímica com CBB, podem ser usados em conjunto como biomarcadores para poluição por óleo diesel e gasolina em U. lactuca. O estudo do metaboloma via espectroscopia vibracional de infravermelho (FTIR) e análise multivariada de dados (HCA, PCA, k-means) permitiu discriminar a maioria das amostras segundo o xenobiótico de interesse. Quando os grupos expostos ao diesel e à gasolina foram analisados separadamente, a análise do intervalo espectral de absorbância das proteínas permitiu o melhor agrupamento das amostras. Os talos expostos ao óleo diesel foram melhor agrupados de acordo com a concentração deste xenobiótico, enquanto aqueles expostos à gasolina foram melhor discriminados de acordo com o tempo de exposição ao combustível. A abordagem analítica ao estudo do metaboloma de U. lactuca mostrou-se eficiente para discriminar alterações bioquímicas consoante à exposição aguda aos xenobióticos. Por se tratar de uma metodologia simples, rápida, sensível e barata possui potencial para desenvolvimento de protocolo de rotina a estudos de biomonitoramento. Abstract : Fossil fuels, such as gasoline and diesel oil account for substantial share of pollution that affects marine ecosystems. Seaweeds have important ecological roles in many ecosystems, but a few researches have been carried out aiming at to unravel the effects of oil derivatives on these organisms, comparatively to the observed for microalgae, invertebrates, and vertebrates. Ulva lactuca (Chlorophyta) was chosen as a biological model for this study due to its cosmopolitan habits, ability to bioaccumulate heavy metals, and tolerance to polluted environments by domestic and industrial effluents. In the present study the effects of diesel oil and gasoline, in combinations of concentrations (0,001%, 0,01%, 0,1%, and 1,0%) and times of exposure (30 min, 1 h, 12 h, and 24 h) were investigated on U. lactuca's ultrastructure, biochemistry, and metabolomics. Scanning electron microscopy (SEM) images, just after 1 h of exposure to diesel oil or to gasoline revealed drastic alterations in thalli mucilage that persist after 12 h and 24 h of exposure. Coomassie Brilliant Blue (CBB) cytochemistry analysis indicated that exposure to gasoline led to disorganization and agglutination of the cytoplasm protein fraction, possibly affecting enzymes bound to organelles' membranes. This effect was lesser intense in thalli exposed to diesel oil, which exhibited little alterations in cytoplasm. Diesel oil-exposed thalli exhibited changes in chlorophyll a and b contents and in carotenoid profile not related to diesel oil concentrations or exposure times. Diesel oil also decreased the polyphenol content and increased the soluble sugars and starch amounts, specially after 12 h exposure, followed by a decrease in these metabolites after 24 h exposure. Chlorophyll a and b contents also were altered in a way not related to concentrations or times of exposure in gasoline-treated thalli. A decrease in the carotenoid and polyphenol amounts and an increase in soluble sugars and starch contents positively correlated to time of exposure were detected in gasoline-treated groups. SEM, cytochemical, and biochemical analyzes revealed higher toxicity to U. lactuca of gasoline than diesel oil, possibly due to the high permeability of mono-aromatic hydrocarbons and ethanol from the Brazilian gasoline blend. Importantly, results also showed that photosynthetic pigments and their biosynthetic pathways resist in a certain extension to injuries caused by gasoline and diesel oil. Besides, the augmented amounts of soluble sugars and starch suggest that hydrocarbons may have been metabolized and incorporated into U. lactuca's energetic pathways, e.g. citric acid cycle. These results indicate that U. lactuca plays an important role on bioremediation of natural habitats. From these results, we suggest that polyphenols, soluble sugars, and starch contents, along with CBB cytochemistry could be used as biomarkers of diesel oil and gasoline pollution in U. lactuca. FTIR-based metabolomics studies followed by multivariate statistical analysis (HCA, PCA, k-means) efficiently discriminated most of the the exposed groups according to the xenobiotic. When diesel oil- and gasoline-exposed groups were analyzed separately, the most accurate clusters were obtained using the spectral window corresponding to the proteins absorbances. Diesel oil-exposed thalli were better clustered according to the concentration of xenobiotic, whereas gasoline-exposed thalli were better grouped according to the time of exposure to this fuel. Since the analytical approach to metabolomics showed to be simple, fast, cheap, and sensible, it is thought to have potential for further development of protocols of routine analysis in biomonitoring studies.

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Robic, Audrey. "Etude de la variabilité chimique, physico-chimique et rhéologique des ulvanes, polysaccharides des parois cellulaires d'algues marines vertes de la famille des Ulves (Ulvales, Chlorophyta)." Nantes, 2008. http://www.theses.fr/2008NANT2104.

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Les algues vertes appartenant aux genres Ulva et Enteromorpha sont communes à travers le monde. Elles prolifèrent localement sous la forme de « marées vertes » et sont source de nuisances. Elles sont riches en polysaccharides parmi lesquels les ulvanes représentent par leurs caractéristiques chimiques et gélifiantes un atout pour valoriser ces algues. Le rendement d’extraction, la variabilité chimique, physico-chimique et rhéologique d’ulvanes d’algues contribuant aux marées vertes (U. Rotundata et U. Armoricana) ont été étudiés en fonction de la période de récolte et du mode de conservation des algues. Les rendements sont maximum à partir d’U. Rotundata en croissance, à la fin de la période de prolifération d’U. Armoricana et à partir d’algues saumurées. La proportion des deux populations moléculaires constitutives des ulvanes est affectée par la période de collecte et le mode de conservation. Des masses élevées sont obtenues à partir d’algues récoltées en période de croissance et conservées par congélation. Le module de conservation des gels d’ulvane est positivement corrélé avec la proportion d’ulvanes de haute masse et la teneur en rhamnose, en acide glucuronique et en sulfate. Parmi différentes conditions d’extractions étudiées, une solution diluée d’acide chlorhydrique à chaud donne un rendement optimal. Des études par microscopie indiquent que les ulvanes ont un caractère hydrophobe marqué conduisant à des structures moléculaires sphériques expliquant les faibles viscosités développées par ces polysaccharides. La gélification des ulvanes en présence d’acide borique et de cations divalents résulterait de l’agrégation de ces sphères Green seaweeds belonging to Ulva and Enteromorpha species are common worldwide. Collected or cultivated for human consumption, they proliferate in the form of “green tides” and result in harmful accumulations. They are rich in polysaccharides and notably in the water soluble ulvan which presents original chemical and gelling properties and afford novel opportunities for the biomass uses. The impact of the period of collect and stabilization treatments on the extraction yield, chemical, physico-chemical and rheological variability of ulvan from species contributing to Brittany “green tides” (U. Rotundata and U. Armoricana) were studied. The highest yields were obtained from actively growing U. Rotundata, from U. Armoricana at the end of the proliferation period and from brined seaweeds. The period of collect and the stabilization treatment affected the proportion of the two macromolecular populations constituting ulvans. The highest molecular weight ulvan was obtained from actively growing seaweeds and stored frozen. The storage modulus of ulvan gels was positively correlated with the proportion of high molecular weight ulvan and with the rhamnose, glucuronic acid and sulfate contents. Among different extraction conditions studied, hot dilute chlorhydric acid solution gave an optimal extraction yield. Microscopic studies indicated that ulvans are hydrophobic which led to the formation of spherical molecular structures that explain the low intrinsic viscosities of ulvan in solution. The gelling properties of ulvan with boric acid and divalent cations would arise from the association of these globules

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Araujo, Leonardo. "Mecanismos de resistência inata e induzida por ulvana à infecção de Colletotrichum gloeosporioides (Penz.) Penz." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93536.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, 2010 Made available in DSpace on 2012-10-24T23:50:58Z (GMT). No. of bitstreams: 1 274964.pdf: 1041847 bytes, checksum: 78f57ef1cf2c57cdff4ea5a802c1bb57 (MD5) Este trabalho teve como objetivo avaliar e comparar os mecanismos de defesa inata e induzida pela aplicação de ulvana à infecção de Colletotrichum gloeosporioides em macieira. Para tanto, plântulas resistentes foram tratadas com água destilada aos 6 dias antes da inoculação (DAI), enquanto que suscetíveis foram pulverizadas com ulvana (10mg/mL). Plântulas foram inoculadas com C. gloeosporioides e a severidade da Mancha Foliar de Glomerella (MFG) foi avaliada diariamente de 4 a 10 dias pós-inoculação (DPI), baseada na estimativa visual da porcentagem de tecido necrosado. Aos 10 DPI, todas as folhas foram destacadas e escaneadas para determinar a área foliar necrosada usando o Software Quant. A germinação dos conídios e a formação de apressórios de C. gloeosporioides foi avaliada às 24, 48 e 72 horas após a inoculação (HAI) na 2a e 3a folha expandida de plântulas. Discos foliares foram coletados, clareados e conservados em lactoglicerol até o exame em microscópio óptico. As atividades de peroxidases e glucanases foram determinadas em tecidos remanescentes da 2a e 3a folha expandida de plântulas de macieira às 24, 48 e 72 HAI. Plântulas com resistência inata nunca apresentaram sintomas da MFG. A ulvana pulverizada aos 6 DAI reduziu significativamente a severidade da MFG em plântulas. A germinação de conídios de C. gloeosporiodes não foi alterada pela resistência inata ou induzida por ulvana. O desenvolvimento de estruturas de infecção em plântulas resistentes foi semelhante às testemunhas, no entanto a pulverização com ulvana inibiu a formação de apressórios e elongamento do tubo germinativo do fungo. A resistência inata e induzida por ulvana aumentou a atividade de POX em plântulas de macieira, mas a atividade de GLU não foi alterada. Em suma, a resistência inata da macieira a MFG parece estar relacionada ao rápido reconhecimento do C. gloeosporioides com maior atividade de POX às 24 HAI. A redução da MFG por ulvana foi associada à menor formação de apressórios e elongamento do tubo germinativo de C. gloeosporioides, além do aumento da atividade de POX em plântulas às 72 HAI. This study aimed to evaluate and compare the innate defense mechanisms and induced by the application of ulvan by infection of Colletotrichum gloeosporioides in apple. The resistance seedlings were treated with distillated water (control) 6 days before inoculation (DBI), while susceptible was sprayed with ulvan (10 mg/mL). Seedlings were inoculated with C. gloeosporioides and severity Glomerella Leaf Spot (GLS) was assessed daily from 4 to 10 days post-inoculation (DPI), based on visual estimation of the percentage of necrotic tissue. At 10 DPI all the leaves were detached and scanned to determine leaf area necrosis using Software Quant. Conidial germination and appressoria formation of C. gloeosporioides was evaluated at 24, 48 and 72 hours after inoculation (HAI) in 2nd and 3rd expanded leaf of seedlings. For this, foliar discs (9mm) were collected, leached and maintained in lactoglicerol until microscopical examination. The peroxidases and glucanases activity was determined in tissue remaining of the 2nd and 3rd expanded leaf of seedlings apple at 24, 48 and 72 HAI. Seedlings with innate resistance never showed symptoms of GLS. Ulvan sprayed at 6 DBI significantly reduced the severity of the GLS in seedlings. Conidial germination of C. gloeosporioides was not changed by either innate resistance or induced by ulvan. The development of structures of infection in resistance seedlings was similar to controls, however the ulvan spraying inhibited appressorium formation and germ tube elongation of fungus. Both innate resistance and induced by ulvan increased the POX activity of apple seedlings, but the activity of GLU was not changed. In sum, the innate resistance of apple against GLS seems to be related to the rapid recognition of C. gloeosporioides with increased activity of POX at 24 HAI. Disease reduction by ulvan was associated with a lesser appressorium formation and germ tube elongation of C. gloeosporioides, as well as enhanced POX activity in seedlings at 72 HAI.

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陳旻佐. "Evaluation on the bioactivity of Ulva lactuca and Ulva wine spent." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/07403601829206019254.

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Kidgell, Joel Thomas. "The structure and bioactivity of ulvan, a sulfated polysaccharide from Ulva (chlorophyta)." Thesis, 2021. https://researchonline.jcu.edu.au/69842/1/JCU_69842_Kidgell_2021_thesis.pdf.

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Joel Kidgell studied ulvan, a unique sulfated polysaccharide from green seaweeds of the genus Ulva. His research detailed how the chemical structure of these molecules is critical in their application as a biomaterial ranging from wound dressings to tissue scaffolds.

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Yu, Cheng-Hao, and 游政豪. "Simulating phosphatic fossilization with Ulva fasciata." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/95178605746485527791.

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碩士 國立清華大學 分子與細胞生物研究所 94 An extraordinary fossil record of multicellular life were found in phosphorites from the Precambrian Doushantuo Formation（550~600 Mya）, southern China. These fossils, which three-dimensional cellular structure details were perfectly preserved, have been classified as animal embryo, larva, and adult forms, as well as multicellular thallophytes, giant acritarch, and spheroidal chlorophyta. The well-preserved structural details indicates a rapid burial process, thus it is possible to simulate fossilization process in laboratory time. Ulva fasciata, a green algae, was selected as the major experimental material, and simplified control factors were apply to explore the most probable factors that influence fossilization and determine the possible roles they play during fossilization process. In previous experimental approach, the replicated morphology of soft-bodied fossils has been attributed to adsorption of pre-existing mineral clays and correlated to bacteria activity. But the interior of the subjects was not mineralized in early experiments. We attempted to develop several phosphorite deposition systems based on conditions of ancient environment and fossils records. We induced the formation of calcium phosphate deposits by increasing the temperature and the following rise of pH value. The results showed that the interior of algal cells was mineralized and detail morphology was preliminarily replicated. The results also indicated that magnesium played an important role in the phoosphorite deposition systems. No deposition occurred within the cells in the absence of magnesium. We suggest that the formation of fossils in Doushantuo Formation may be the consequence of a catastrophic rapid burial and phosphorites deposition at an elevated temperature on the results mentioned above.

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Hung, Yueh-Hao, and 洪悅豪. "Study on the Production of Ulvan and Ulvan Oligosaccharides and Their Biological Activity and Assessment of Lactic Acid Fermentation from Ulva Residue." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5r3es7.

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碩士 國立臺灣海洋大學 食品科學系 106 This study is aim to analyze characteristic and bioactivities of ulvan oligosaccharides produced by enzymatic hydrolysis and investigate conditions of lactic acid fermentation of Ulva residue. Firstly, ulvan were gained from Ulva lactuca powder that treated by hot-water (110oC/75 min), then collected by ultrafiltration system (> 30 kDa), and precipitated in 95% ethanol. The yield of ulvan is 15.89% (15.89 g of ulvan obtained from 100 g of Ulva lactuca powder), and the total sugar, reducing sugar, uronic acid, sulfate, protein and total phenols of ulvan are 48.59%, 3.05%, 30.22%, 21.29%, 0.47% and 0.11%, respectively. HPLC chromatogram is shown molecular weights (MW) of ulvan are mainly 769 kDa polysaccharides which relative ratio of fractions are 53.2%. FT-IR spectra of ulvan is presented O-H, C=O, C-O and S=O stretching. Moreover, using ulvan to induce marine bacteria Pseudomonas vesicularis MA103 and Aeromonas salmonicida MAEF108 could produce ulvan-degrading enzymes. Activities of ulvan lyase, amylase, cellulase, and xylanase were 1.93 U/mL, 3.78 U/mL, 2.72 U/mL, and 1.62 U/mL respectively which produced by MA103 in 3 days, and were 0.22 U/mL, 0.17 U/mL, 0.19 U/mL, and 3.23 U/mL respectively which produced by MAEF108 in 2 days. Further, ulvan were hydrolyzed by crude enzymes solution of MA103 and MAEF108, and differentiated by ultrafiltration system (< 3 kDa) to acquire ulvan oligosaccharides (UOS3K). The yield of UOS3K is 4.69% (4.69 g of ulvan gained from 100 g of Ulva lactuca powder), and the total sugar, reducing sugar, uronic acid, sulfate and total phenols of ulvan oligosaccharides are 7.42%, 7.17%, 2.54%, 13.19% and 0.73%, respectively. HPLC chromatogram is shown MW of UOS3K are mainly 800 Da oligosaccharides which relative ratio of fractions are 82.0%. FT-IR spectra of UOS3K is presented O-H, C=O, C-O and S=O stretching. Secondly, the bioactivity of ulvan or UOS3K were evaluated by angiotensin I converting enzyme (ACE) inhibitory, antioxidant activities and anticoagulant activities in vitro. In ACE inhibitory assay (ACEI), inhibition of ulvan (50 mg/mL) and UOS3K (12.5 mg/mL) were 18.41% and 81.86%. IC50 value of UOS3K on ACEI was 0.451 mg/mL (Peptide concentration). In antioxidant activity assays, the DPPH scavenging activity of ulvan (10 mg/mL) and UOS3K (10 mg/mL) were 52.46% and 27.27 %; the Fe2+ chelating ability of ulvan (20 mg/mL) and UOS3K (10 mg/mL) were 4.62% and 97.98%; both of ulvan and UOS3K were not shown the reducing power. In anticoagulant activity assays, wich are activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) using rabbit plasma, UOS3K did not prolong the aggregation time compared to blank group. However, UOS3K could decrease the aggregation level to 94% and 78% in APTT and PT test. Thirdly, utilized Ulva residue which removed the ulvan from Ulva lactuca to induce MA103 and MAEF108 producing crude enzymes was investigated. Activities of ulvan lyase, amylase, and xylanase were 1.97 U/mL, 3.91 U/mL, and 2.08 U/mL respectively which produced by MA103 in 3 days, and activities of enzymes produced by MAEF108 were no significant. Additionally, hydrolyzing conditions of the Ulva residue were evaluated. Finally, Ulva residue polysaccharide hydrolysate was added 0.5% (w/v) yeast extract as nitrogen source, calcium carbonate as neutralizing agent, and then fermented by 1% (v/v) of Lactobacillus plantarum BCRC12327 at 30oC for 36 hr, the lactic acid concentration was 35.97 g/L and lactic acid yield was 15.65% (15.65 g of lactic acid gained from 100 g of Ulva residue).

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Chou, Hsiang-Ling, and 周湘凌. "Effects of Ulva fasciata Hexane Extract or Ulva fasciata Oligosaccharides on Glucose Metabolism in Human Caco-2 and HepG2 Cells." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7k529g.

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碩士 國立臺灣海洋大學 食品科學系 107 Insulin resistance (IR) is one of the characteristics of type 2 diabetes. This study was aimed to investigate the anti-diabetics effects and mechanisms of Ulva fasciata hexane extract (UF) or Ulva fasciata oligosaccharides (UO) in human intestinal and hepatic cells. Firstly, the fatty acid analysis revealed that the most abundant unsaturated fatty acids in UF were α-linolenic acid (C18:3 n3; 17.51 mg/g), linoleic (C18:2 n6c; 9.68 mg/g), oleic (C18:1 n9c; 1.98 mg/g) and palmitoleic (C16:1; 1.08 mg/g). The contents of carotenoids, chlorophyll a and chlorophyll b were 0.30 g/g, 0.09 mg/g and 0.10 mg/g, respectively. The total carbohydrate content of UO was about 15%, molecular weight was less than 1 kDa. (曾，2018). UF and UO demonstrated antioxidative activity. The DPPH radical-scavenging assay revealed that the potential of 20 μg/mL UF and 1000 μg/mL UO were equivalent to 2.0 μg/mL of vitamin E and 0.3 μg/mL of vitamin C. Iron chelating asaay demonstrated that the potential of 20 μg/mL UF and 1000 μg/mL UO were equivalent to 3.0 μg/mL and 4.0 μg/mL of EDTA. Superoxide radical-scavenging assay found that the potential of 20 μg/mL UF and 1000 μg/mL UO were equivalent to 54.6 μg/mL and 95.8 μg/mL of gallic acid. Besides, UF (2.5 ~ 20 μg/mL) and UO (7.8 ~ 125 μg/mL) significantly inhibited sucrase activity in human intestinal Caco-2 cells to 58.8% and 39.1% of control group, respectively. The sucrase inhibitory effect of UO (7.8 ~ 125 μg/mL) was equivalent to anti-diabetic drug Acarbose (125 μg/mL) in Caco-2 cells. In human hepatic HepG2 cells, UF (2.5 ~ 20 μg/mL) significantly improved translocation of glucose tranporter GLUT4 to cell membrane (114.5 ~ 173.8% of control), enhanced glucose uptake (102.7 ~ 176.2%), and increased intracellular glycogen content (0.07 μg/μL more than control), as well as accelated ATP content (132.3 ~ 159.6%) and declined lactate production (26.4 ~ 61.6 pmol/μL less than control). Notable, the regulatory effects of UF were correlated with decreased IRS-1 (Ser307) phosphorylation and activated PI3K/AMPK/AKT signaling. Additionally, treatment with UF (10 μg/mL) or UO (500 ~ 1000 μg/mL) decreased ROS production (56.0% or 44.0 ~ 60.8% of control) and suppressed interleukin (IL)-8 secretion (115.0 pg/mL or 136.1 ~ 186.9 pg/mL less than control). In conclusion, the anti-diabetic effects of UF may through decreasing intestinal sucrase activity, activation hepatic PI3K signaling, and increasing translocation of GLUT4, as well as increasing glucose utilization, and ameliorate intracellular ROS and IL-8 production. Therefore, UF is a potent agent to attenuate IR.

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Yu, Hsin-Han, and 余信翰. "Studies on physiological activity of Ulva clathrata extractives." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/76976501784191734176.

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碩士 國立臺灣海洋大學 食品科學系 99 The purpose of this research was to clarify the antioxidant activity of Ulva clathrata water soluble extractives. The maximal polysaccharides contents were extracted by adding one hundred volumes of de-ionized water to original algae weight, and heating at 100oC for 1 hour. The hot-water extractives by acid and base treatment or precipitation used adding four volumes of 95% ethanol. Each extractive from Ulva clathrata was hydrolyzed by enzyme. The tentative compositions and antioxidant activities of extractives were determined, respectively. According to results, it show that reducing power, chelating Fe2+ effect, scavenging of DPPH and Trolox equivalent antioxidant capacity of each extractive were increase as concentration increase. After acid and base treating, the reducing power and chelating Fe2+ effect of extractives were better than hot-water extract only. Each extractive from Ulva clathrata hydrolyzing with α-amylase or cellulase, it showed the reducing sugar content of later was more than former; and the antioxidant activity of cellulase treatment group exhibited the best among other groups. Therefore it supposed that the antioxidant activity of water soluble extractives of Ulva clathrata was offered by degradation of its polysaccharides.

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Dissertations / Theses on the topic 'Ulva'

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