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Pereira, Rui Alexandre Martins. "Nitrile hydratase from a thermophilic Bacillius isolate." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267488.
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Baraniecki, Cheryl Anne Paulette. "Characterization of Sphingomonas paucimobilis ANT 17, an oil degrading bacterial isolate from Antarctica." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0010/MQ60091.pdf.
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Van, der Linden Liesl Elizabeth. "The genetic basis of resistance in Arabidopsis thaliana ecotype Kil-0 against Ralstonia solanacearum isolate BCCF 402 from Eucalyptus." Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/31224.
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Taylor, Suzanne. "Towards the construction of a bacterial artificial chromosome (BAC) library of Fragaria vesca L. to isolate a gene controlling seasonal flowering." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369543.
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Verniz, Luiz Alfredo de Souza. "Avaliação da produção de complexo celulásico por diferentes isolados bacterianos utilizando bagaço de cana como substrato indutor." Universidade Federal de São Carlos, 2011. https://repositorio.ufscar.br/handle/ufscar/6997.
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Previous issue date: 2011-08-29Financiadora de Estudos e Projetos
The searching for new fuel sources has motivated new studies which aim to produce the second-generation of ethanol, also called 2G . However, the costs to produce that fuel are still high because the sugarcane bagasse is not considered a residue any more, but a subproduct that can generate income to the industries that produce it, being a vapor energy form to the company or an electricity source to sell. The use of the sugar cane bagasse to produce 2G ethanol requires a significant amount of lignocellulolitic enzymes. The main aim of this study is to reduce the cost of the production of these enzymes by means of studying isolated lignocellulolitic bacterium from Stenochironomus larva. The goal is to evaluate its productivity in several submersed fermentation processes and surface fermentations. Submersed fermentations were conducted using sugar cane bagasse and soy meal as substrates and different concentrations were applied in culture media. A total of 11 isolated enzymes were evaluated initially, and re-selected at each new stage of the process. The enzyme cultures were conducted by the reduction sugars quantification and the results enabled us to demonstrate that the bacteria Sphingobium and Pseudomonas were the most productive when compared to the others. Our results have highlighted that those bacteria were strongly influenced by the addition of different organic nitrogen sources in the fermentation culture. From the introduction of those components, the enzyme activity became higher and this fact was corroborated by the index of 4.36 U/mg protein for Xilanase, 0.12 U/mg protein for FPase and 2.31 U/mg protein for CMCase.
A busca por novas fontes de combustíveis tem feito com que diferentes estudos surgissem com o objetivo de produzir etanol de segunda geração, conhecido como etanol 2G. Os custos para se produzir esse combustível ainda são elevados, uma vez que o bagaço de cana não é mais considerado um resíduo, mas sim um subproduto que gera renda para a usina que o detém, seja na forma de energia (vapor) ou na venda de energia elétrica. Para se conseguir utilizar o bagaço de cana a fim de produzir etanol 2G é necessário uma grande quantidade de enzimas lignocelulolíticas. Visando a redução do custo de produção dessas enzimas para que o processo de produção do etanol 2G se torne viável, o presente trabalho tem o objetivo de estudar diferentes isolados bacterianos lignocelulolíticos de larvas de Stenochironomus, pretendendo avaliar seu rendimento na produção dessas enzimas. Para se realizar essa avaliação, fermentações submersas foram realizadas utilizando o bagaço de cana e farelo de soja como substrato indutor e diferentes concentrações de meios de cultivo. Um total de 11 isolados foram avaliados inicialmente e selecionados a cada nova etapa. A partir dos resultados dos ensaios enzimáticos, que foi realizado através da quantificação de açúcares redutores, foi demonstrado que as bactérias Sphingobium e Pseudomonas se destacaram na produção dessas enzimas em relação às demais bactérias inicialmente testadas. Os resultados deste trabalho evidenciou que essas bactérias foram fortemente influenciadas pela adição de diferentes fontes de nitrogênio orgânico em seu meio de cultivo para as fermentações, o que gerou uma maior atividade enzimática obtendo índices de 4,36 U/mg de proteína para Xilanase, 0,12 U/mg de proteína para FPAse e 2,31 U/mg de proteína para CMCase, a partir da introdução desses componentes aos meios.
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Marais, Laurette Marlize. "Characterization of bacteria isolated from a platinum mine tailings dam / Laurette Marais." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8721.
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Contamination from various sources has a huge impact on soil health and microbial community composition. Metal contamination of soil in mining scenarios is of concern and is not adequately addressed, particularly with respect to the microbial community. The mining industry is one of the largest contributors to heavy metal contamination of soil in South Africa, especially since the country is one of the major mining countries in the world. Platinum mining is of special importance, since the largest percentage of the world’s reserves of platinum group metals are found and mined in South Africa. Metals from mining activities become irreversibly immobilized in soil systems because they cannot be degraded and has a huge impact on soil systems. In this study, bacteria was isolated from soil samples collected from a platinum mine tailings dam outside Rustenburg. During the warm sampling season (March 2006) most isolates were found, especially in sites 3 and 4. During the colder and drier season (May 2006) there were less isolates. Most of the isolated cultures also displayed a wide temperature growth range, mostly between 24°C - 37°C. Paenibacillus lautus and Bacillus subtilus DN-10 had a growth range between 5°C - 40°C. Culturable metal tolerant bacteria were isolated, purified and identified using 16S rDNA sequences. Nine different species were found namely Paenibacillus lautus strain DS19, Paenibacillus lautus, Paenibacillus sp. C15, uncultured Paenibacillaceae, Bacillus subtilis strain DN-10, Bacillus sp. KDNB5, Bacillus cereus, Stenotrophomonas maltophilia and Alcaligenes sp. DJWH 146-2. The ability of these strains to tolerate metal concentrations were explored by determining their minimum inhibitory concentrations for a selection of metals e.g. aluminum, barium, cobalt, chromium, cadmium, copper, iron, lead, manganese, nickel and mercury. Most isolates were able to tolerate >5mM of the Al\Ni alloy and cobalt. Transmission electron microscopy was used to determine the location of metals inside bacterial cells and electron dispersive X-ray analysis was used to determine the levels of metals inside microbial cells. Bacillus subtilis DN-10 (LDK0306) showed a high MIC (>5mM) for most metals used, except Hg. This strain also had a high percentage (10.26%) of Pb detected in its cells by EDX. This was the highest percentage detected. Plasmids were extracted from the identified strains and can help gain a better understanding of metal tolerance mechanisms used by these isolates.Thesis(MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013
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Puttanlek, Chureerat. "Microbial degradation of dichlobenil." Thesis, University of Kent, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314268.
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Almansa, Ruiz Jose Carlos. "Bacterial profiles and antibiograms of the bacteria isolated of the exposed pulps of dog and cheetah canine teeth." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/30685.
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Objectives: The aims of this study was to investigate the RC microbiota in CCF canine teeth in the domestic dogs (Canis familiaris) and cheetahs (Acinonyx jubatus), identify the possible factors related to the presence of aerobic or anaerobic bacteria and evaluate and evaluate antibiotic susceptibility of bacteria isolated. Animals: Thirty nine animals suffering from CCF of their canine teeth were included in this study, of which 20 were dogs and 19 were cheetahs. Procedures: Evaluation of the oral cavity of animals while under general anaesthesia was performed and those without necrotic pulps or those that had received antibiotic therapy in the previous two weeks were excluded. Microbial samples were taken from 63 RC of which 27 were from dogs and 36 were from cheetahs. Strict anaerobic and aerobic techniques were used in parallel for plating, incubation and identification of the bacteria isolated in this manner. In an attempt to evaluate the sensitivity of the culture media and anaerobic technique used, additional samples were collected after the samples for bacterial isolation had been taken from the last eight pulps. These comprised those from six cheetahs and two dogs and were analysed using culture techniques and an initial screening with the 16S rRNA-specific PCR. Results: • Dogs: A total of 49 cultivable isolates were recovered belonging to 19 different bacterial species and 13 different genera. Individual RC yielded a maximum of four bacterial species. Of the bacterial isolates, 4.08 % were strict anaerobes, being represented by Clostridium acetobulitycum (2.04 %) and Prevotella melalinogenica (2.04 % ). The incidence of aerobic bacteria and facultative anaerobic bacteria in this study were 18.36 % and 77.56 %respectively of all the bacterial isolates. Of these Pasteurella multocida ( 10.20 % ), Corynebacterium spp. (10.20 %), Moraxella spp. (8.17 %), Bacillus spp. (6.12 %), Aeromonas salmonicida (6.12 %), Escherichia coli (6.12 %) and Pseudomonas aeruginosa (6.12 %) were the bacteria most frequently isolated. In summary, the RC microflora was found to be predominantly Gram negative facultative anaerobic microorganisms. The antibiotic agents that showed the highest efficacy in vitro against the different bacteria isolates were Enrofloxacin (85.21 % ), Gentamicin (92.39 %), Chloramphenicol (89.13 %). • Cheetahs: A total of 59 cultivable isolates, belonging to 19 different microbial species and 13 different genera were recovered from 36 RC sampled. Thirty-two (54.49 %) of the cultivable isolates were Gram positive while 27 (45.71 %) were Gram negative. Individual root canals each yielded a maximum of six species. Four RC had no cultivable bacteria. The bacterial micro flora recovered from the RC of the animals showed a higher number of facultative anaerobes (62.72 % of all the bacterial isolates). Aerobic isolates were 28.81 %, and strict anaerobes 8.47 % of all the isolates. The latter species comprised Clostridium sordelli (5.08 % ), and Clostridium septicum (3.38 % ). The species with the highest isolation frequency were Bacillus spp. (22.13 %), Pasteurella multocida (10.16 %), Corynebacterium spp. (8.47 %), Enterococcus spp. (8.47 %), Moraxella spp. (8.47 %) and Pseudomonas aeruginosa (5.25 %). In summary, the bacteria isolated from the RC were Gram positive facultative anaerobic bacteria. The antibiotics, which showed the highest efficacy in vitro against the different bacteria isolates, were Enrofloxacin (91.96 %), Gentamicin (86.37 %) and Orbifloxacin (86.28 %). • Nucleic Acid-Base detection: In dogs, Gram negative and Gram positive bacterial species were equally represented. Anaerobic bacterial species predominated at 83.3 % (5/6) of the species detected. On the other hand, in cheetahs, the bacterial species isolated by the PCR method showed a prevalence of anaerobic bacteria (60.8 %, 14/23), while facultative anaerobes were isolated in 30.2 % (7 /23) of cases and aerobic bacteria in 8.6 % (2/23). Conclusions and Clinical Relevance: This study has indicated that the microbial flora in any single infected RC is much more diverse than it has been shown using cultural techniques alone and can contain potentially uncultivable bacterial species. Some of these species may represent potentially new phylotypes, which may be involved in endodontic infections and ultimatelyin periradicular periodontitis, and should therefore be considered in any future studies involved in defining endodontic pathogens. CopyrightDissertation (MSc)--University of Pretoria, 2012.
Companion Animal Clinical Studies
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Saijonma-Koulumies, Leena E. M. "Bacterial interference in the control of canine pyoderma." Thesis, Royal Veterinary College (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368117.
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Willard, Kyle. "Investigation of exopolysaccharide producing bacteria isolated." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71627.
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Thesis (MSc)--Stellenbosch University, 2012.ENGLISH ABSTRACT: The deterioration of harvested sugarcane as a result of bacterial growth causes major losses of sucrose and a build-up of exopolysaccharides (EPS). Polysaccharides present during production increase the massecuite viscosity, which negatively influences evaporation and crystallisation. In this study 38 culturable EPSproducing bacteria were isolated from milled sugarcane. Analysis of the EPS showed the ubiquitous presence of glucose, however, 14 polysaccharides also contained mannose, fructose or galactose. In vitro treatment using Chaetomium erraticum dextranase to evaluate is effectiveness indicated that 37 of the EPS were hydrolysed to some extent. There were 21 polysaccharides that were only partially digested. The capacity of the isolates to produce EPS on different sugars indicated a correlation between sucrose and polysaccharide formation in 37 isolates. The results indicate there are more species involved in EPS production than previously thought as well as the presence of non-dextran polysaccharides.
AFRIKAANSE OPSOMMING: Bakteriële groei veroorsaak ‘n afname in gehalte, sukrose en ‘n verhoging in die hoeveelheid van eksternepolisakkeriede (EPS). Die verhoogde konsentrasie van polysakkariede gedurende die verwerkingsprosses veroorsaak ‘n verhoging in “massecuite” viskositeit. Hierdie verskynsel het ‘n nadelige uitwerking op die verdamping en kristalvorming van die produk. In gemaalde skuikerriet was 38 groeibare EPS-produserende bakterieë geisoleer. Die geanaliseerde EPS van hierdie bogenoemde bakterieë was daar in almal glukose teenwoordig. In 14 van hulle was mannose, fruktose en galaktose ook gevind. Die in vitro effektiwieteit van Chaetomium erraticum dekstranase op die EPS het gewys dat 37 het tot ‘n mate gehidroliseer maar 21 was net gedeeltelik verteer. As gevolg van die bo-genoemde resultate was daar gevind dat sukrose was ‘n noodsaaklike subtraat vir EPS produksie in die geisoleerde bakterieë. In hierdie studie was bevestig ‘n groter verskiedenheid EPS-produserende bakterieë gevind was en dat hulle assosiasie aan sukierriet prossering meer kompleks is as wat vooreen gedink was.
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Reyes, Nikolle Susanne. "Marine bacterial isolates utilize unique mercury resistance mechanisms." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/25416.
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Feio, Maria Jose Faria. "Characterisation and identification of two novel species of sulphate-reducing bacteria from marine environments." Thesis, University of Portsmouth, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327002.
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This study describes the characterisation and identification of two species of sulphate-reducing bacteria isolated from marine environments. The isolate coded Ind 1 was recovered from the heavily corroded hull of an oil storage vessel moored off the Indonesian coast. An isolate, referred to as Al 1, originated from a soured oil reservoir in Alaska. Observations using microscopy (light, scanning electron and atomic force) revealed that cells were Gram-negative, rod-shaped and very motile. Physiological characterisation, analysis of the fatty acid profiles and partial and full 16S rRNA sequencing demonstrated strong similarities between the two species and members of the Desulfovibrio genus. The position of the strains within phylogenetic trees showed Al 1 clustering closely with Desulfovibrio vietnamensis. Ind 1 revealed a high degree of similarity with both Desulfovibrio gigas and Desulfovibrio gabonensis and these three strains formed a separate cluster in the delta subdivision of the Proteobacteria. However, whole-cell protein profiles and Fourier-transform infrared spectroscopy studies showed that there is enough dissimilarity between the two isolates and the remaining species of the genus Desulfovibrio to consider Al 1 and Ind 1 as new separate species. Purification, physico-chemical and spectroscopic characterisation of the key enzymes involved in the sulphate metabolism was carried out for both isolates. Nuclear magnetic resonance and electron paramagnetic resonance studies revealed that the proteins of Al 1 and Ind 1 exhibited various features in common with their counterparts from other members of the genus Desulfovibrio. In particular, proteins from Ind 1 showed many similarities with the enzymes previously described for D. gigas. Based on the obtained results, the classification of Ind 1 as Desulfovibrio indonensiensis sp. nov. and Al 1 as Desulfovibrio alaskensis sp. nov. are proposed. The overall results highlight the complexity of the relationship between cell physiology and the organisms' environmental impact.
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Lawson, Andrew Jeffrey. "The prevalence of Campylobacter species in human gastroenteritis : a molecular approach." Thesis, Open University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342935.
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Santos, Tania Regina dos. "Reserva nitrogenada no genero Beijerinckia isolada da rizosfera de cana-de-açúcar." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-06102011-113221/.
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Beijerinckia sp., bactéria de vida livre fixadora de nitrogênio, comumente encontrada em solos tropicais lateríticos. A cianoficina produzida por cianobactérias é a única reserva nitrogenada intracelular descrita até hoje. O presente trabalho teve como principal objetivo verificar o acúmulo de material nitrogenado intracelular associado à Fixação Biológica de Nitrogênio em cinco isolados de Beijerinckia da rizosfera de cana-de-açúcar (Saccharum sp.). Os resultados mostraram um aumento na concentração de proteína celular total concomitantemente a atividade da nitrogenase durante a fase estacionária de todos os isolados. A fixação de nitrogênio durante esta fase sugere que o destino do nitrogênio fixado seriam os grânulos de armazenamento. A análise química desta reserva confirmou a presença de arginina em teor muito elevado em relação aos demais aminoácidos sugerindo uma reserva nitrogenada diferente da cianoficina. Em recombinantes de Escherichia coli confirmou-se um possível gene envolvido no armazenamento de material nitrogenado em Beijerinckia sp.Beijerinckia sp. bacteria free-living nitrogen-fixing, commonly found in tropical lateritic soils. The cyanophycin produced by cyanobacteria is the only intracellular nitrogen reserve described to date. This study aimed to verify the intracellular buildup of nitrogen associated with Biological Nitrogen Fixation in five Beijerinckia isolated from the rhizosphere of sugarcane (Saccharum sp.). The results showed an increase in total cellular protein concentration concomitantly nitrogenase activity during the stationary phase of all isolates. The nitrogen fixation during this phase suggests that the fate of fixed nitrogen would be the storage granules. Chemical analysis of the reserve confirmed the presence of very high content of arginine in relation to other amino acids suggesting a different reserve of cyanophycin. In recombinant Escherichia coli confirmed a possible gene involved in nitrogen storage material in Beijerinckia sp.
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Al-Hadhrami, Mohamed N. (Mohamed Nasser). "Degradation of Phenolic Acids by Azotobacter Species Isolated from Sorghum Fields." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc501189/.
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Sorghum plants excrete phenolic acids which reduce subsequent crop yields. These acids accumulate in field soil by combining with soil and clay particles to form stable complexes which remain until degraded by bacterial metabolism. The amount of phenolic acids in soil samples were obtained by gas chromatography measurements, while Azotobacter populations were obtained by plate counts in 40 sorghum field samples from Denton County, Texas. One can conclude that increasing the Azotobacter population in the soil increased the degradation rate of phenolic acids proportionally. It is proposed that seed inoculation will introduce selected strains of Azotobacter into the soil. The presence of Azotobacter should increase crop size in subsequent plantings.
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Sislak, Christine Demko. "Novel Thermophilic Bacteria Isolated from Marine Hydrothermal Vents." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1486.
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As part of a large study aimed at searching for patterns of diversity in the genus Persephonella along the north to south geochemical gradient of the ELSC, ten novel strains of Alphaproteobacteria were isolated unexpectedly. Using defined media under microaerophilic conditions to enrich for Persephonella from chimney samples collected at the seven vent fields on the ELSC and the dilution to extinction by serial dilution method to purify cultures, a total of ten strains belonging to the Alphaproteobacteria were isolated. Two of these isolates, designate MN-5 and TC-2 were chosen for further characterization and are proposed as two new species of a novel genus to be namedThermopetrobacter. Both strains are aerobic, capable of chemoautotrophic growth on hydrogen and grow best at 55°C, pH 6 and 3.0% NaCl. Strain MN-5 is capable of heterotrophic growth on pyruvate and malate and TC-2 is only able to grow heterotrophically with pyruvate. The GC content of MN-5 is 69.1 and TC-2 is 67 mol%. GenBank BLAST results from the 16S rRNA gene reveal the most closely related sequence to MN-5 is 90% similar and the most closely related sequence to strain TC-2 is 89% similar.
Sampling at a shallow marine vent on the coast of Vulcano Island, Italy in 2007 led to the isolation of a novel species of Hydrogenothermus, a genus within the Hydrogenothermaceae family. This isolate, designated NV1, represents the secondHydrogenothermusisolated from a shallow marine vent. NV1 cells are rod-shaped, approximately 1.5μm long and 0.7μm wide, motile by means of a polar flagellum and grow singularly or in short chains. Cells grow chemoautotrophically using hydrogen or thiosulfate as electron donors and oxygen as the sole electron acceptor. Growth was observed between 45 and 75°C with an optimum of 65°C (doubling time 140 min), pH 4.0-6.5 and requires NaCl (0.5-6.0% w/v). The G+C content of total DNA is 32 mol%.
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Luckarift, Heather Rosemary. "The production of chiral hydroxylated products from new bacterial isolates." Thesis, University of Warwick, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322689.
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Boyiri, Blaise B. "Probiotic Potential of Bacterial Isolates From ‘Amabere amaruranu’ Cultured Milk." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2389.
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Probiotics are viable nonpathogenic microbes that positively affect host health. Probiotics inhibit infection, activate immunity, and promote mucosal-barrier development. Many microbes have probiotic activity. Nonetheless, the selection of stable strains and their specific mechanism(s) of action are not fully elucidated. Bacteria from ‘Amabere amaruranu’ cultured milk from Kenya were isolated and identified by PCR sequence analysis of the 16S rRNA gene. Isolates were examined for stability to acid and bile, antimicrobial activity, mucin production, and degradation and sensitivity to antibiotics, hence their potential for probiotics. Lactobacillus isolates were acid unstable, bile-stable, nonmucinolytic, and presented antibacterial activity. L. rhamnosus cell fractions increased MUC4 and MUC3 expression in colon cells. Bacillus isolates were acid and bile stable, nonmucinolytic and lacked antimicrobial activity. In conclusion, Lactobacillus isolates that were nonmucinolytic, stable in bile, demonstrated antibacterial activity, sensitive to antibiotics, and stimulated increase MUC4 and MUC3 levels in colon cells could be potential probiotics.
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Gato, Arlena Maria Guimarães. "Micropropagação, resgate de embriões e avaliação do efeito de microrganismos endofíticos em helicônias." Universidade Federal do Amazonas, 2009. http://tede.ufam.edu.br/handle/tede/4487.
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SUFRAMA - Superintendência da Zona Franca de Manaus
The flowers and ornamental plants cultivation stands out as an important agronomical activity. But despite the economical and market potential of these regional native species: helicônia, bastão, sorvetão and other plants, is necessary more basic studies about the use of advanced techniques in getting propagated material with quality assurance and good phytosanitary aspect. The objective of this study was to obtain plantlets from floral apices of Heliconia rauliniana and embryos rescue of H. marginata, identifies, inoculation of bacterial isolates and evaluate the effect of these microorganisms in the development of micropropagated plants. Established the plants micropropagation process, it was isolated from matrices root, bacterial isolates and, according to the classification criteria of activity levels of nitrogen biological fixation, phosphate solubilisation and auxin production, it was selected six Heliconia rauliniana isolates and eight of Heliconia marginata. The first experiment were inoculated in in vitro plants of H. rauliniana, the B4, B5, B8, B13, B16 and B18 bacterial isolates and on H. marginata micropropagated plants, the B1, B2, B4, B6, B7, B10, B12, B14 and B16 isolates and, then transferred to plastic boxes containing sterilized substrate Plantmax (Horticulture) and maintained under greenhouse. After 60 days of inoculation, it was realized the evaluation of root growth promotion, selecting the three isolates that showed the best results: B18, B5 and B13 (H. rauliniana) and B7, B6 and B10 (H. marginata). In the second experiment we used the B18, B5, B13 and B6, B7, B10 selected in the first experiment and inoculated in 60 plants, distributed on five treatments: control, B18, B5 and B13, cocktail x plant and control, B6, B7, B10, cocktail x plant with 12 plants per treatment. The results presented after 60 days, don’t were significant on the level of 0.05% and one good faith coefficient of 95% (ANOVA) for root growth promotion, number of leaves, plant height, fresh weight and dry weight. The plants survive was 83.3%. For microorganisms identify, it was used the analysis of the fragment about 800 bp of the 16S rDNA (Primer 27f). The sequencial analysis via Blast showed three bacterial groups: Burkholderia, Ralstonia e Enterobacteriaceae (Pantoea/Erwinia).
O cultivo de flores e plantas ornamentais tropicais destaca-se como importante atividade agrícola. Mas, apesar das potencialidades econômicas e de mercado dessas espécies nativas da região: helicônia, bastão, sorvetão e outras, são necessários mais estudos básicos sobre a utilização de técnicas avançadas na obtenção de material de propagação com garantia de qualidade e bom aspecto fitossanitário. O objetivo deste trabalho foi obter mudas micropropagadas a partir de ápice floral de Heliconia rauliniana e de resgates de embriões de H. marginata, identificação, inoculação dos isolados de bactérias e avaliar o efeito desses microrganismos no desenvolvimento das plantas micropropagadas. Estabelecido o processo de micropropagação das plantas foram isolados das raízes das matrizes, isolados bacterianos e, de acordo com os critérios de classificação dos níveis de atividades em fixação biológica de nitrogênio, solubilização de fosfato e produção de auxina, foram selecionados seis isolados da Heliconia rauliniana e oito da Heliconia marginata. No primeiro experimento, foram inoculados nas plantas micropropagadas de H. rauliniana, os isolados bacterianos B4; B5 (Enterobacter); B8; B13 (Ralstonia); B16; B18 (Enterobacter) e nas plantas micropropagadas de H. marginata, os isolados B1; B2; B4; B6 (Enterobacter); B7 (Enterobacter); B10 (Burkholderia); B12; B14 e; B16 e, posteriormente transferidas para caixas plásticas contendo substrato esterilizado PlantMax (Horticultura) e mantidas em casa de vegetação. Após 60 dias de inoculação foi realizada a avaliação de promoção de crescimento de raiz, selecionando-se os três isolados que apresentaram os melhores resultados por espécie: Heliconia rauliniana, Enterobacteriaceae (Pantoea/Erwinia), B18 e B5 Enterobacteriaceae (Pantoea/Erwinia e B13 (Ralstonia) e Heliconia marginata B7 Entereobacteriaceae (Pantoea/Erwinia), B6 Entereobacteriaceae (Pantoea/Erwinia) e B10 Burkholderia. No segundo experimento foram utilizados os isolados bacterianos B18 Enterobacteriaceae (Pantoea/Erwinia): B5 Enterobacteriaceae (Pantoea/Erwinia, B13 Ralstonia e B6, Entereobacteriaceae (Pantoea/Erwinia), B7, Entereobacteriaceae (Pantoea/Erwinia), B10, Burkholdeia selecionados no primeiro experimento e inoculados em 60 plantas, distribuídas em cinco tratamentos: controle, B18 Entereobacteriaceae (Pantoea/Erwinia: B5 Entereobacteriaceae (Pantoea/Erwinia e B13 Ralstonia, coquetel x planta e controle, B6 Entereobacteriaceae (Pantoea/Erwinia), B7 Entereobacteriaceae (Pantoea/Erwinia), B10 (Burkholderia), coquetel x planta com 12 plantas por tratamento. Os resultados apresentados após 60 dias, não foram significativos a nível de 0,05 % e um coeficiente de confiança de 95 % (A NOVA) para promoção de crescimento de raiz, número de folhas, altura de planta, peso fresco e peso seco. A sobrevivência das plantas foi de 83,3 %. Para identificação dos microrganismos foi usado o seqüenciamento de fragmento de aproximadamente 800 pb do gene 16S rDNA (“primer 27f). A análise das sequencias via Blast mostrou três grupos de bactéria: Burkholderia, Ralstonia e Enterobacteriaceae (Pantoea/Erwinia).
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Yiu, Pik-yu. "Characterization of 2 novel clostridium species isolated from patients with bacteremia." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31972275.
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Abou, Assaf Nasser. "Degradation of the herbicide EPTC by isolated soil bacteria /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487693923199045.
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Park, Chan-Woo. "Effective organic acid fermentation of garbage by isolated bacteria." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/145366.
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Álvarez-Carretero, Sandra. "BACTpipe : Characterization of bacterial isolates based on whole-genome sequence data." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-15033.
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The technological advances have led to faster and more cost-effective sequencing platforms, making it quicker and more affordable to generate genomic sequence data. For the study of bacterial genome, two main methods can be used, whole-genome sequencing and metagenomic shotgun sequencing, of which the first is the mostly used in the past years. As a consequence of these advances, a vast amount of data is currently available and the need of bioinformatics tools to efficiently analyse and interpret it has dramatically increased. At present, there is a great quantity of tools to use in each step of bacterial genome characterization: (1) pre-processing, (2) de novo assembly, (3) annotation, and (4) taxonomic and functional comparisons. Therefore, it is difficult to decide which tools are better to use and the analysis is slowed down when changing from one tool to another. In order to tackle this, the pipeline BACTpipe was developed. This pipeline concatenates both bioinformatics tools selected based on a previous testing and additional scripts to perform the whole bacterial analysis at once. The most relevant output generated by BACTpipe are the annotated de novo assembled genomes, the newick file containing the phylogenetic relationships between species, and the gene presence-absence matrix, which the users can then filter according to their interests. After testing BACTpipe with a set of bacterial whole-genome sequence data, 60 genes out of the 18195 found in all the Lactobacillus species analysed were classified as core genes, i.e. genes shared among all these species. Housekeeping genes or genes involved in the replication, transcription, or translation processes were identified
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Löfmark, Sonja. "Incidence, emergence, persistence and mechanisms of antimicrobial resistance in clinical isolates and normal microbiota /." Stockholm, 2007. http://diss.kib.ki.se/2007/978-91-7357-127-2/.
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Webb, Martin Darren. "Biotransformation of pentachlorophenol by actinomycetes isolated from compost." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243205.
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Jandhyam, Haritha Lakshmi. "Molecular phylogenetic analysis of novel spiroplasma isolates." Click here to access thesis, 2009. http://www.georgiasouthern.edu/etd/archive/spring2009/haritha_l_jandhyam/jandhyam_haritha_l_200901_ms.pdf.
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Thesis (M.S.)--Georgia Southern University, 2009."A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by Laura B. Regassa. ETD. Includes bibliographical references (p. 64-69) and appendices.
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Krey, Whitney B. "Siderophore production by heterotrophic bacterial isolates from the Costa Rica upwelling dome /." Online version of original thesis, 2008. http://hdl.handle.net/1912/2394.
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Krey, Whitney B. (Whitney Blair). "Siderophore production by heterotrophic bacterial isolates from the Costa Rica upwelling dome." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43114.
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Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2008.Includes bibliographical references (p. 54-59).
(cont) An increased understanding of heterotrophic bacterial strategies for acquiring nutrients and trace elements is critical for elucidating their impact on biogeochemical cycling in the ocean. It is estimated that iron is a limiting nutrient for phytoplankton growth in over 30% of the open ocean, but still little is known about bacterial strategies for iron acquisition. Siderophore (Fe ligand) production by bacteria may play a major role in influencing the bioavailability of iron in the ocean. Despite the importance of siderophores in the environment, only limited information from a select group of bacteria is available. On a cruise through the Costa Rica Dome (CRD) upwelling region in July 2005, a library of 867 isolates from five depth profiles inside and outside of the dome was obtained and screened for siderophore production using the Chrome Azurol-S (CAS) assay. Phylogenetic affiliation of 134 isolates was determined by sequencing the 16s rDNA gene, and determined that gamma proteobacteria such as Alteromonas, Pseudoalteromonas, Halomonas, and Marinobacter dominated the collection, while alpha-proteobacteria such as Roseobacter were also represented. The isolates obtained from stations in the CRD showed greater siderophore-producing capabilities between 55m and 100m while strains isolated from outside the CRD had shallower peak (-8-35m) production. Functional group determination showed that hydroxamate production dominated from 50-150m, while hydroxamate and catechol production is roughly equal in shallower waters. By characterizing the siderophores produced by these isolates and determining the genetic make-up of the population, these findings further our understanding of how heterotrophic microbes affect biogeochemical processes and the competitive nature of nutrient acquisition.
by Whitney B. Krey.
S.M.
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Gerard, Jeffery M. "Antibiotic secondary metabolites of bacteria isolated from the marine environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25055.pdf.
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Ramirez-Lopez, Lina Marcela. "Heat inactivation of thermo-resistant bacteria isolated from poultry offal." Connect to this title online, 2006. http://etd.lib.clemson.edu/documents/1171902361/.
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Ngo, Maleguel Epse Kamdem Jaqueline. "Coaggregation and biofilm formation by bacteria isolated from chronic wounds." Thesis, Cardiff Metropolitan University, 2010. http://hdl.handle.net/10369/942.
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There is a growing recognition that biofilms are the principal cause of chronicity or persistence in infections. Biofilms have been implicated in chronic wounds as a cause of delayed healing. However, only few wound management strategies treat wounds with the assumption that biofilm may be the cause of failure to heal. The fact is biofilms are difficult to treat because of their resistance to antimicrobial agent. Biofilm formation is known to be a three stage process that has been found in dental plaque to be influenced by cell to cell recognition also called coaggregation. The main aim in this study was to investigate the ability of bacteria isolated from chronic wounds to form biofim in vitro and the possible role of coaggregation in the establishment of biofilm. 164 pairs of clinical bacteria were tested for ability to coaggregate. Out of 71 isolates 58 (81.69%) gave positive coaggregation score and 13 (18.3%) did not coaggregate. The presence of biofilm was tested using 59 of the 71 bacteria and all isolates (100%) indicated an ability to form biofilm in vitro with various degrees of adherence. 74.57% were strongly adherent, 15.26% moderate, and 10.17% weakly adherent There was a significant association between the ability of isolates to coaggregate and to form biofilm (p<0.05) Using isolates that had been recovered from the same patients, matrices were constructed from 5 patients to investigate the structure of the network. The probability that a node will be connected was high (p>0.01) indicating that bacteria in chronic wounds are highly connected to one another. Random and selected node removal from the network revealed that bacteria in chronic wounds may be strongly dependent on one another and favour a polymicrobial rather than a monospecies infection. Network analysis also demonstrated coaggregation ability of some bacteria to act as pioneers in the establishment of the biofilm and provided support for the idea that coaggregation might influence biofilm formation in chronic wounds.
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Nandivada, Lakshmi Sarada. "Beta-lactam resistance in gram-negative bacteria isolated in India." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/27101.
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The most important resistance mechanism to beta-lactam antibiotics is the plasmid-mediated beta-lactamase and the common criterion for the epidemiology of these enzymes is the determination of their biochemical characteristics. Surveys of plasmid-encoded beta-lactamases of Gram-negative bacteria, used to investigate their relative clinical importance, have been poorly performed and rarely conducted outside the developed world. A survey of uropathogenic strains and of salmonellae and shigellae, isolated in south India in 1984, revealed a higher incidence of ampicillin resistance (minimum inhibitory concentration [MIC] > 10mg/1) than had ever been reported before (Enterobacteriacea 82%, salmonellae 90%, shigellae 60%). Only the enterobacterial strains showed any significant resistance to the first generation cephalosporin, cephalosporin, cephaloridine (MIC > 10mg/1). However, 66% of the salmonellae strains were cefuroxime resistant. A small proportion of all species conferred resistance to third generation cephalosporins. In the individual species, there was a very high incidence of ampicillin resistance (E. coli 76% Klebsiella spp 96%) and cephaloridine resistance (E.coli 57% Klebsiella spp 69%). Many of the ampicillin resistant strains harboured either auto-transferable or mobilisable plasmids (40%). Characterisation of the plasmid DNA from the E.coli transconjugants revealed the existence of 37 different plasmids types. The transconjugants from klebsiella, salmonella and shigella possessed fewer plasmids types than those from E. coli. Most plasmids possessed resistance genes to aminoglycosides and to six or more drugs. Beta-lactamase studies revealed that TEM-1 was the most predominant enzyme in all transconjugant strains followed by OXA-1, SHV-1, TEM-2, OXA-2 and the novel enzyme SAR-2. The SAR-2 enzyme was fully characterised and had a higher pI (8.3) than any previously characterised plasmid-mediated beta-lactamase. It had a broad-spectrum activity with the molecular weight of 36000. In addition the unusual observations of E.coli strains producing both the PSE-1 and PSE-2 beta-lactamases and strains hyperproducing the TEM-1 were made and these strains were studied further. The development and mechanisms of resistance to beta-lactam/beta-lactamase inhibitor combinations (ampicillin and clavulanic acid) have been performed with laboratory strains possessing the ampicillin resistance plasmid R1. The results show that challenge with clavulanic acid alone did not affect the expression or integrity of the beta-lactamase whereas challenge with the combination of ampicillin and clavulanic acid caused radical changes with the expression of the beta-lactamase. In some cases there were multiple copies of genes which resulted in hyperproduction of TEM-1 enzyme and this was sufficient to resist the combinations. Unfortunately, these variants also conferred resistance to second and third generation cephalosporins. Evidence of this type of resistance to clavulanic acid is now emerging in clinical practice.
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Xiraphi, Polyhronia. "Safety attributes of lactic acid bacteria isolated from fermented sausages." Thesis, University of Surrey, 2009. http://epubs.surrey.ac.uk/843262/.
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Lactic acid bacteria (LAB) were isolated during the production and the ripening of Greek dry fermented sausages. Samples were taken at different stages, and 150 "wild' strains were isolated. The majority of the strains isolated were assigned to the species Lactobacillus plantarum biotype (1) (43.3 %) followed by Lb. curvatus, Lb. pentosus (10.7 %), Lb. brevis biotype (1) (8.7 %), Lactococcus lactis subsp. lactis biotype (1) (6.7 %) and Leuconostoc mesenteroides subsp. mesenteroid.es biotype (2) (5.3 %). The possibility of bacteriocin production was tested using the agar well diffusion assay (AWDA). One strain was found to produce bacteriocin (Leuconostoc mesenteroides E131) and its purification was attempted using precipitation with ammonium sulphate, cation exchange, and reverse phase chromatography. Moreover, the purification of curvaticin L442 was attemped, a bacteriocin produced by Lactobacillus curvatus L442, isolated from Greek traditional fermented sausage prepared without addition of starters. The bacteriocin was purified by 50% ammonium sulphate precipitation, cation exchange, reverse phase and gel filtration chromatography. Lb sakei I154, a bacteriocin producing strain isolated from Italian fermented sausage, and the semi-purified bacteriocin from Leuconostoc mesenteroides E131 were validated via industrial trials to evaluate whether the product (fermented sausages) maintains the technological characteristics and the traditional quality characteristics. Three fermentations under controlled conditions were conducted and at the end of these fermentations, products were sliced and packaged under controlled atmosphere (80% N2 + 20% CO2) and stored at 4+/-2 °C for 12 weeks to determine the shelf life of the product. Finally, from the previous industrial trials the proper production parameters were determined as well as the most effective packaging techniques, resulting in the conduction of a Standard Operation Procedures Guide concerning the whole production of traditional fermented sausages.
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Jacobs, Anelet. "Investigation and comparison of adherence- and biofilm-forming capacities of yellow-pigmented Chryseobacterium, Elizabethkingia and Myroides spp. isolated from South African aquaculture systems." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/19634.
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Thesis (MSc)--University of Stellenbosch, 2007.ENGLISH ABSTRACT: In the aquaculture setting, opportunistic pathogens are present as part of the normal aquatic microflora, colonizing surfaces in fish tanks as part of biofilm communities, and often causing severe economic losses to the aquacultural industry. Isolates belonging to the genera Chryseobacterium, Elizabethkingia, Myroides and Empedobacter have been isolated from diseased fish, and are responsible for causing secondary fish infections, fish- and food-product spoilage, and have been described as etiological agents of various human diseases. Thirty-four Chryseobacterium and Elizabethkingia spp. and five Myroides and Empedobacter spp. isolates, obtained from various diseased fish species and biofilm growth in South African aquaculture systems, were characterised genetically using 16S rRNA gene PCR restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD) PCR, whole cell protein (WCP) and outer membrane protein (OMP) analyses. Genetic heterogeneity was displayed by the Myroides and Empedobacter spp. study isolates following OMP analysis, although 16S rRNA gene RFLP, RAPD-PCR and WCP analysis did not allow for differentiation of these isolates. A high degree of genetic heterogeneity was displayed by the Chryseobacterium and Elizabethkingia spp. study isolates following OMP analysis, 16S rRNA gene RFLP with MspI, and RAPD-PCR with primer P2. However, based on the results obtained by WCP analysis, 16S rRNA gene RFLP with CfoI and TaqI, and RAPD-PCR with primer P1 the isolates appeared genetically very homogeneous. High MAR indices and potential multi-drug resistance phenotypes were obtained for the Myroides and Empedobacter spp. and some of the Chryseobacterium and Elizabethkingia spp. isolates by antimicrobial susceptibility testing. Primary adherence and the influence of environmental changes on adherence was investigated by a modified microtitre-plate adherence assay. Nutrient composition, temperature and hydrodynamic incubation conditions were observed to influence adherence abilities of all study isolates. In addition, adherence varied greatly among isolates of the genera Chryseobacterium and Elizabethkingia, as opposed to a consistent strong adherence profile observed for the Myroides and Empedobacter spp. isolates. The influence of cell surface properties such as capsule presence and cell surface hydrophobicity, on primary adherence of the isolates was also investigated. Quantitative analysis of capsular material revealed the presence of thick capsular material surrounding the Myroides and Empedobacter spp. and some of the Chryseobacterium and Elizabethkingia spp. isolates, but could not be directly associated with adherence. Hydrophobicity were investigated using the salt aggregation assay (SAT) and bacterial adherence to hydrocarbon test (BATH). A very hydrophilic cell surface was observed for all of the Myroides and Empedobacter spp. isolates, and majority (74%) of the Chryseobacterium and Elizabethkingia spp. isolates. Cell surface hydrophobicity could not be correlated to the adherence of the Myroides and Empedobacter spp. isolates, and only SAT-determined hydrophobicity could be positively correlated to adherence of Chryseobacterium and Elizabethkingia spp. isolates under certain conditions. Coaggregation studies were performed between the study isolates and various important clinical and aquacultural microorganisms. High coaggregation indices were observed between the Myroides and Empedobacter spp. isolates and E. faecalis and S. aureus, and between E. faecalis, S. enterica serovar Arizonae, S. aureus and Listeria spp. and the Chryseobacterium and Elizabethkingia spp. isolates. Biofilm-forming capacity of the study isolates in an environment simulating their natural environment was investigated microscopically using a flow cell system. Typical ‘cone-like’ biofilm structures were observed for selected strains of both Myroides and Empedobacter spp. and Chryseobacterium and Elizabethkingia spp. isolates. The effect of increased hydrodynamics on biofilm architecture was seen through the narrowing of the biofilm structures and the formation of single cell chains towards the increased hydrodynamic area of the flow chambers. Chryseobacterium and Elizabethkingia spp. and Myroides and Empedobacter spp. appear to be potential primary biofilm-formers associating with a variety of microbes thus perpetuating their survival in a variety of aquatic habitats.
AFRIKAANSE OPSOMMING: Opportunistiese patogene kom gereeld in akwakultuur sisteme voor as deel van die akwatiese mikroflora wat dikwels biofilms vorm op oppervlaktes in hierdie sisteme. Visinfeksies veroorsaak deur hierdie patogene lei tot ernstige ekonomiese verliese vir akwakultuur industrieë. Chryseobacterium, Elizabethkingia, Myroides en Empedobacter spp. is reeds voorheen van verskeie geïnfekteerde visspesies geïsoleer hierdie bakterieë is verantwoordelik vir sekondere visinfeksies, die bederf van vis- en kosprodukte, asook menslike siektes. Vier-en-dertig Chryseobacterium en Elizabethkingia spp. en 5 Myroides en Empedobacter spp. isolate, geïsoleer vanaf verskeie geïnfekteerde visspesies en biofilm-groei in Suid Afrikaanse akwakultuur-sisteme, is geneties met behulp van 16S rRNS geen PKR restriksie fragment lengte polimorfisme (RFLP), toevallig geamplifiseerde polimorfiese DNS (TGPD) PKR, heel-sel protein (HSP) en buitemembraan protein (BMP) analise gekarakteriseer. BMP analise het getoon dat die Myroides en Empedobacter spp. isolate geneties heterogeen is, alhoewel 16S rRNS TGPD-PKR, TGPD-PKR en HSP analise nie tussen die isolate kon onderskei nie. BMP analise, 16S rRNS TGPD-PKR met MspI en TGPD-PKR met inleier P2 was meer suksesvol as HSP analise, 16S rRNS TGPD-PKR met CfoI en MspI, en TGPD-PKR met inleier P1, om onderskeid te tref tussen die Chryseobacterium en Elizabethkingia spp. isolate en het gedui op ‘n hoë vlak van genetiese heterogeniteit tussen hierdie isolate. Beide die Chryseobacterium en Elizabethkingia spp. en Myroides en Empedobacter spp. isolate het ‘n hoë vlak van antibiotika weerstand getoon wat dui op ‘n menigvuldigde antibiotika weerstands-fenotiepe. Primêre vashegting vermoëns en die invloed van omgewingsfaktore op vashegting is met behulp van ‘n gemodifiseerde mikrotiterplaat vashegtings toets ondersoek. Vashegting van die isolate is beïnvloed deur variasies in die samestelling van die medium, temperatuurveranderings en verskillende hidrodinamiese inkubasie kondisies. Inteenstelling met die sterk vashegtingsvermoë van die Myroides en Empedobacter spp. isolate, het die vermoë om vas te heg grootliks tussen die Chryseobacterium en Elizabethkingia spp. isolate gevarieer. Verder is ondersoek ingestel op die invloed van seloppervlak eienskappe soos die teenwoordigheid van kapsules en hidrofobisiteit op die isolate se vermoë om aan oppervlaktes te heg. Die Myroides en Empedobacter spp. isolate en verskeie Chryseobacterium en Elizabethkingia spp. isolate is omring deur dik kapsules, maar geen verband tussen vashegting en die teenwoordigheid van kapsules kon bepaal word nie. Die sout aggregasie toets (SAT) en bakteriële vashegting aan koolwaterstowwe (BVAK) toets was gebruik om die hidrofobisiteit van die isolate se seloppervlaktes te bepaal. Die Myroides en Empedobacter spp. isolate en 74% van die Chryseobacterium en Elizabethkingia spp. isolate het ‘n baie hidrofiliese seloppervlak getoon. Slegs die hidrofobisiteit bepaal deur die SAT toets het ‘n positiewe verwantskap met die aanhegtingsvermoë van die Chryseobacterium en Elizabethkingia spp. isolate getoon. Mede-aggregasie tussen die isolate en verskeie belangrike mediese en akwakultuur mikroörganismes is ook ondersoek. Die Myroides en Empedobacter spp. isolate het ‘n sterk assosiasie met E. faecalis en S. aureus getoon Die Chryseobacterium en Elizabethkingia spp. isolate het sterk met E. faecalis, S. aureus, S. enterica serovar Arizonae en Listeria spp. geassosieer. Vloei-sel studies is uitgevoer om die biofilm-vormingsvermoë van die isolate te ondersoek. Vir beide die Myroides en Empedobacter spp. en Chryseobacterium en Elizabethkingia spp. isolate is tipiese kegelagtige biofilm stukture waargeneem. Die invloed van verhoogde hidrodinamiese kondisies in die vloei-sel het vernouing van die biofilm strukture en die vorming van enkel-sel kettings tot gevolg gehad. Vanuit hierdie studie is afgelei dat die Myroides en Empedobacter spp. en Chryseobacterium en Elizabethkingia spp. isolate onder verskeie kondisies aan oppervlaktes kan vasheg en dus potensiële primêre biofilm-vormings organismses is. Hierdie organismes besit ook die vermoë om met ‘n verskeidenheid ander organismes te assosieer, wat waarskynlik hulle suksesvolle oorlewing in akwakultuursisteme verseker.
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Yu, Wai-yee Annie. "Epidemiological and emm gene analysis of non-m-typeable group A streptococcus isolates from Hong Kong." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23340204.
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Abe, Lucienne M. "Adhesion and internalization of group A streptococcus isolates found in Hawaii." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=764803591&SrchMode=2&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1233167604&clientId=23440.
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Yiu, Pik-yu, and 姚碧如. "Characterization of 2 novel clostridium species isolated from patientswith bacteremia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31972275.
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Çakıcı, Özgür. "Biochemical and genetic characterization of halobacterium salinarium strain isolated from Tuz Lake in central Anatolia." Ankara : METU, 2004. http://etd.lib.metu.edu.tr/upload/12604752/index.pdf.
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GOMES, Jessé Malveira. "Avalição toxicológica da linhagem bacteriana 358.1 isolada do petróleo sobre Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)." Universidade Federal de Campina Grande, 2017. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/769.
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O milho é uma das culturas mais produzida e importante no mundo, sendo utilizada na alimentação humana e animal. O Brasil é um dos maiores produtores desse grão, sendo o terceiro maior produtor do mundo. Apesar de uma produção elevada, a produtividade é comprometida pela ação de insetos pragas, sendo a Spodoptera frugiperda Smith a de maior atuação nessa cultura. Em meio a esse desafio, o uso constante de inseticidas é utilizado com intuito de minimizar as perdas nas lavouras, porém, ocasionando grandes impactos ambientais, bem como a contaminação de trabalhadores rurais. Uma das estratégias viáveis e promissoras na supressão de pragas tem sido o manejo integrado de pragas (MIP), que tem como alicerce o uso isolado ou consorciado de técnicas de controles de pragas, sendo o controle biológico uma das ferramentas mais sustentáveis do ponto de vista ecológico. Desta forma, o presente trabalho teve como objetivo avaliar a toxicidade da cepa bacteriana 358.1 isolada do petróleo e o sobrenadante da cultura de células sobre o controle de lagartas de 2º e 3º instares de S. frugiperda, comparando as taxas de mortalidade e efeitos sobre seu desenvolvimento e com inseticidas químicos comerciais. O experimento consistiu de duas etapas, o primeiro ensaio foi realizado com lagartas de 3º instar com três diluições diferentes da cepa 358.1, sobrenadante da cultura de células, solução salina como controle negativo e o inseticida fenpropatrina como controle positivo. No segundo ensaio utilizou-se lagartas de 3º e 2º instares, a cultura celular da cepa 358.1 em sua concentração total (4 x 108 UFC/mL), seu sobrenadante da cultura, como controle negativo água destilada e testemunha positiva o produto comercial flubendiamida. Os experimentos com a cepa 358.1, sobrenadante da cultura de células e os produtos químicos testados não resultaram em uma taxa de mortalidade de S. frugiperda significante, porém, a cepa 358.1 e seu sobrenadante da cultura resultaram no aumento da duração da fase larval e em distúrbios morfofisiológicos do inseto, ocasionando, inclusive, no surgimento de adultos com asas atrofiadas, sendo desta maneira, promissores para à realização de novos testes.
Corn is one of the most produced and important crops in the world, utilized for human and animal feeding. Brazil is one of the top producers of this grain, being the third biggest producer worldwide. Despite the great production, the productivity is compromised due to the activity of insect pest. Because of this challenge, the continuous use of insecticides is done aiming to minimize lost in the crops. However, it causes major environmental impact and it is also contaminating rural workers. One of the viable and promising strategies to the pest suppression has been the pest integrated management (PIM), which is based on the use of isolated or consortium of pest controlling techniques, the biological control being one of the most sustainable tools in an ecological perspective. Therefore, the present study had the goal of evaluating the toxicity of the 358.1 bacterium strain isolated from the oil and supernatant of the cell culture under control of caterpillars from 2nd and 3rd instars of S. frugiperda, comparing the death rates and effects on their development, and also comparing with commercial chemical insecticides. The experiment consisted in two stages; the first assay was done with 3rd instar caterpillar with three different dilutions from the 358.1 strain, supernatant of the cell culture, saline solution as negative control, and fenpropatrina insecticide as positive control. On the second assay, 3rd and 2nd instars caterpillars were used, the cell culture from the 358.1 strain on its total concentration (4 x 108 UFC/mL), supernatant of the cell culture, distilled water as negative control and flubendiamida, a commercialized product, as the positive control. The experiments with the 358.1 strain, supernatant of the cell culture and the tested chemical products didn’t show a significant death rate for S. frugiperda, however, the 358.1 strain and supernatant of the cell culture resulted in an increase in the larval phase duration and on morphophysiological disturbs on the insect, resulting yet in the emergence of adults with atrophied wings, thus being promising to the realization of new tests.
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Saeedi, Baharak. "Characterization of clinical enterococcal isolates in Swedish hospitals : studies on genetic relatedness and high-level gentamicin resistance /." Linköping : Dept. of Molecular and Clinical Medicine, Univ, 2005. http://www.bibl.liu.se/liupubl/disp/disp2005/med899s.pdf.
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Hamza, Ali. "Growth and Biofilm Formation of Bacteria Isolated from Contaminated Platelet Units." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22852.
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Bacterial contamination of platelet concentrates (PCs) poses the major transfusion-associated infectious risk. Coagulase negative staphylococci (CoNS), the predominant platelet contaminants, are recognized as one of the leading causes of hospital-acquired infections due to their ability to form biofilms (surface-attached aggregates). In this study, 29 CoNS strains were characterized for their growth and biofilm formation abilities in media and PCs. Twenty-five strains were aerobic including Staphylococcus epidermidis, S. capitis, and S. chromogenes, while four were identified as the anaerobe S. saccharolyticus. Biofilm-associated icaA and icaD genes were amplified from eight strains. Interestingly, only six of those strains were biofilm-positive. Sequencing of S. capitis icaD revealed no mutations that could explain differences in biofilm phenotypes. Growth of CoNS in PCs varied significantly between strains. This study provides preliminary evidence that slow-growing biofilm-positive S. epidermidis are more likely to be missed during platelet culture, highlighting the need for improved screening methods.
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O'Donnell, C. M. "A study of nitrosation in bacteria isolated from the operated stomach." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233842.
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Failor, Kevin Christopher. "Identification and characterization of ice nucleation active bacteria isolated from precipitation." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/92196.
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Since the 1970s, a growing body of research has suggested that bacteria play an active role in precipitation. These bacteria are capable of catalyzing the formation of ice at relatively warm temperatures utilizing a specific protein family which aids in the binding of water molecules. However, the overall biodiversity, concentration, and relationship of ice nucleation active (ice+) bacteria with air mass trajectories and precipitation chemistry is not well studied. Precipitation events were collected over 15 months in Blacksburg, VA and ice+ bacteria were isolated from these samples. From these samples, 33,134 total isolates were screened for ice nucleation activity (INA) at -8 °C. A total of 593 of these isolated positively confirmed for INA at the same temperature in subsequent tests. The precipitation events had a mean concentration of 384±147 colony forming units per liter. While the majority of confirmed ice+ bacteria belonged to the gammaproteobacteria, a well-studied class of bacteria, including ice+ species of Pseudomonas, Pantoea, and Xanthomonas, two isolates were identified as Lysinibacillus, a Gram-positive member of the Firmicute phylum. These two isolates represent the first confirmed non-gammaproteobacteria with INA. After further characterization, the two isolates of Lysinibacillus did not appear to use a protein to freeze water. Instead, the Lysinibacillus isolates used a secreted, nanometer-sized molecule that is heat, lysozyme, and proteinase resistant. In an attempt to identify the mechanism responsible for this activity, species type strains were tested for INA and UV mutants were generated to knock out the ice+ phenotype. Based on these results, only members of the species L. parviboronicapiens exhibit INA and the genes responsible for the activity may lie within a type-1 polyketide synthase/non-ribosomal peptide synthase gene cluster. This gene cluster is absent from the genomes of all non-ice+ strains of Lysinibacillus, and contains mutations in five of the nine ice nucleation inactive mutants generated from the rain isolated strain. To better understand the phylogenetic relationship among ice+ Lysinibacillus, a comprehensive reference guide was compiled to provide the most up-to-date information regarding the genus and each of its species. This reference will be available to other researchers investigating Lysinibacillus species or other closely related genera.PHD
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GIBBS, SHAWN G. "ANTIBIOTIC RESISTANT BACTERIA ISOLATED FROM THE AIR OF SWINE CONFINEMENT OPERATIONS." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin974839805.
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余慧儀 and Wai-yee Annie Yu. "Epidemiological and emm gene analysis of non-m-typeable group A streptococcus isolates from Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31969987.
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Heard, R. G. "An investigation of the antibiotic resistance genes in bacteria isolated from a veal calf rearing farm." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233597.
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Cook, Marisa Anne. "Replicons derived from endogenously isolated plasmids used to classify plasmids occurring in marine sediment bacteria." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/25736.
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Magalhães, Andreia Filipa Afonso. "Assessment of the antimicrobial activity of bacterial isolates from frogs' skins from urban zones." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17177.
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Mestrado em Biologia Molecular e CelularAs populações de anfíbios têm decaído ao longo dos últimos anos devido a inúmeros fatores, tais comos, a perda de habitat, a contaminação/poluição e um dos mais importantes, as doenças. Estas perdas originam também a perda de diversidade genética das espécies, podendo comprometer a sua aptidão e também capacidade de adaptação. Tendo em conta todos estes fatores, é necessário proceder à preservação das populações de anfíbios, independentemente do local em que se encontram ser contaminado, pristino, rural ou urbano. Sabendo que os anfíbios de zonas urbanas podem ser uma fonte importante para a diversidade genética da espécie e que estão expostos, tal como as populações de zonas naturais, a agentes patogénicos, sendo que normalmente são populações negligenciadas a nível de proteção, urge a necessidade de as avaliar e proteger, nomeadamente contra agentes patogénicos. De uma forma geral, esta proteção é conferida de uma forma inata por estruturas ao nível da pele, que fazem parte do seu sistema imunitário. Estas são glândulas granulares responsáveis pela produção de compostos peptídicos capazes de inibir o crescimento de agentes patogénicos. Em acréscimo, a microbiota existente na pele estimula e complementa a atividade destas secreções. Com base nestes factos, este trabalho teve como objetivos: i) avaliar de que forma fatores como as estações do ano (Primavera e Outono) e o género, podem influenciar a microbiota cultivável da pele de Pelophylax perezi de zonas urbanas, ii) avaliar se os isolados bacterianos da pele apresentam atividade antimicrobiana e iii) avaliar o potencial dos isolados bacterianos com atividade antimicrobiana enquanto possíveis agentes probióticos, na presença de um agente patogénico. Os resultados obtidos mostraram diferenças entre locais ao nível das espécies isoladas, sendo poucas as espécies comuns entre locais. Além disso, foi evidenciado que num total de 120 isolados, 19 possuíam atividade antimicrobiana face a Bacyllus aquimaris e Aeromonas salmonicida. Também se verificaram diferenças na atividade antimicrobiana entre estações do ano, existindo um maior número de espécies com atividade antimicrobiana no Outono. Dos isolados com atividade antimicrobiana, os três com maior atividade, Pseudomonas rhizosphaerae, Pseudomonas fluorescens e Bacillus mycoides foram selecionados para a segunda fase do trabalho, em que se avaliou o seu potencial enquanto possíveis agentes probióticos. Após exposição, in vivo, de girinos aos probióticos, em simultâneo com A. Salmonicida, verificou-se que estes evitavam mortalidade dos girinos, bem como diminuíam o dano peroxidativo quando comparados com os valores do agente patogénico. Dos três probióticos B. mycoides mostrou ser aquele com maior capacidade de estimular as enzimas antioxidantes, sendo o agente probiótico com os valores mais baixos de dano peroxidativo.
Amphibian populations have declined over the past few years due to numerous factors such as habitat loss, contamination / pollution and one of the most important, diseases. These losses also result in the loss of genetic diversity of the species, which may compromise their fitness and ability to adapt. Taking all these factors into account, it is necessary to preserve amphibian populations, regardless of being found in contaminated, pristine, rural or urban sites. Given that urban amphibian populations can be an important source for genetic diversity of the species and that they are exposed, such as populations of natural areas, to pathogens, there is a need for assess and protect them against pathogenic agents. Generally, this protection is conferred in an innate way by skin structures, which are part of your immune system. These are granular glands responsible for the production of peptidic compounds capable of inhibiting the growth of pathogens. In addition, the microbiota in the skin stimulates and complements the activity of these secretions. Based on these facts, this work had as objectives: i) to evaluate how factors such as seasonality (spring and autumn) and gender can influence the cultivable microbiota of Pelophylax perezi skin in urban areas; ii) assess the ability of the bacterial skin isolates to present antimicrobial activity and iii) evaluate the potential of bacterial isolates with antimicrobial activity as potential probiotic agents. The obtained results showed differences between sites at the level of the isolated species, with few common species between sites. In addition, it was evidenced that in a total of 120 isolates, 19 had antimicrobial activity against Bacyllus aquimaris and Aeromonas salmonicida. There were also differences in antimicrobial activity between seasons, with a higher number of species with antimicrobial activity in the autumn. Of the isolates with antimicrobial activity, the three with the highest activity, Pseudomonas rhizosphaerae, Pseudomonas fluorescens and Bacillus mycoides were selected for the second phase of the study, in which their potential action as probiotic agents was evaluated. After in vivo exposure of the tadpoles to the probiotics, along with A. salmonicida, these were found to decrease the mortality of tadpoles as well as to decrease the peroxidative damage, when compared to the values obtained from the exposure to the pathogen. From the three probiotics B. mycoides revealed to be the one with the greatest capacity to stimulate the antioxidant enzymes, being the probiotic agent with the lowest values of peroxidative damage.
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Citir, Gozde. "A Study On Cobalt Adaptation And Memory Retention Of Freshwater Bacteria Isolates." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612824/index.pdf.
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The mucus-dwelling bacteria previously isolated from the surface
of a freshwater fish species (Alburnus alburnus from Lake Mogan,
Ankara), were studied to discover their cobalt resistance. The minimum
inhibitory concentrations (MIC) were determined for a total of thirty six
bacterial isolates. The results of the resistance studies led us to design
experiments on adaptation to cobalt and subsequent memory retention.
Three selected isolates were exposed to an inhibitory cobalt
concentration as a mixed culture and individually. The delayed
formation of colonies along with competitive exclusion of one of the
isolates in the mixed culture were recorded. The delay for colony
formation was followed up for liquid culture conditions. After some of
our isolates acclimated to cobalt and started to exhibit constant time of
growth period, it is assumed that they were adapted. We regarded
adaptation as a result of memory formation. Next, we did a further study
to find out how long this memory could be retained via serial multiple
passages in cobalt free medium. We expressed our observations
quantitatively by measuring the growth by using spectrophotometer and
by performing viable counts. Interestingly, where there was a high CFU,
the photometric values were very low. We interpreted the finding such
that the presence of cobalt above tolerance limits were causing size
reduction in the cells. So that their presence was underestimated by
optic devices in visible range. Our study hinted that freshwater bacteria
was adapting cobalt in a memory based mechanism and able to retain
this memory for some time.
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N, Chung S., and 鍾淑女. "Purification and Characterization of Biodegradation of EDTA Chelate by Bacterial Isolate." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/79253564998343942507.
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