Dissertations / Theses: 'Rhizoids'

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Honkanen, Suvi. "Genetic basis of rhizoid development in the liverwort Marchantia polymorpha." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:e80beb1c-4483-4ea1-a3d5-4279caa48ecc.

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The evolution of specialised rooting structures was one of the key morphological innovations that allowed the first multicellular plants to colonise land more than 470 million years ago. The first land plants likely resembled modern bryophytes with a rooting structure that consists of filamentous rooting cells called rhizoids, which are morphologically similar to the root hairs of vascular plants. This thesis describes identification of genes required for rhizoid development in a model bryophyte, the liverwort Marchantia polymorpha. The aim was to identify the conserved and novel aspects of the gene regulatory networks for filamentous rooting cell development in land plants. Agrobacterium-mediated T-DNA transformation of haploid M. polymorpha spores was used to generate 150,000 M. polymorpha T-DNA insertion lines, which were screened for defects in rhizoid development. 204 rhizoid defective mutants were isolated which allowed identification of 25 genes required for M. polymorpha rhizoid development. The role of the class I RSL (ROOT HAIR DEFECTIVE SIX-LIKE) genes as positive regulators of root hair and rhizoid differentiation was found to be conserved between liverworts and vascular plants. This suggests that the class I RSL gene mechanism is ancient and originated before the two lineages diverged more than 440 million years ago. Furthermore, the M. polymorpha class I RSL gene MpRSL1 is required for development of gemmae and mucilage papillae, which similarly to rhizoids form from single epidermal cells that elongate to form an outgrowth. Moreover, MpRSL1 is under negative feedback regulation of the FEW RHIZOIDS1 (FRH1) microRNA. Many genes required for rhizoid elongation were similar with those required for root hair elongation, suggesting that these genes are likely to have been part of the genetic network downstream of class I RSL genes in the common ancestor of liverworts and vascular plants.

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Buyukkileci, Ali Oguz. "Investigation Of Sugar Metabolism In Rhizopus Oryzae." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608622/index.pdf.

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Rhizopus oryzae is a filamentous fungus, which can produce high amounts of L(+)-lactic acid and produces ethanol as the main by-product. In an effort to understand the pyruvate branch point of this organism, fermentations under different inoculum and glucose concentrations were carried out. At low inoculum size (1x103 spores ml-1), high amount of lactate (78 g l-1) was produced, whereas high ethanol concentration (37 g l-1) was obtained at high inoculum sizes (1x106 spores ml-1). Decreasing working volume increased lactate production significantly at high inoculum sizes (1x105 and 1x106 spores ml-1), but did not influenced the physiology at low inoculum sizes (1x103 and 1x104 spores ml-1). In shake flask cultures, at low initial glucose concentrations biomass yield was high and lactate and ethanol yields were low. Higher lactate and ethanol and lower biomass yields were obtained by increasing the initial glucose concentrations. In alginate immobilized, semi-continuous cultures with cell retention, glucose level in the medium was kept at low values. Like in shake flask cultures, as the glucose concentration decreased lactate and ethanol yields decreased and biomass yields increased. Increasing the glucose concentration by a pulse of glucose caused increases in branch point enzyme activities, as well as in concentrations of the metabolites. In fed batch cultures higher biomass yield (0.25 g DCW g glucose-1) could be obtained. Lactate dehydrogenase was influenced by the inoculum size and glucose concentration more than pyruvate decarboxylase and alcohol dehydrogenase. It showed higher activity at lactate producing fermentations. Unlike lactate dehydrogenase, pyruvate decarboxylase and alcohol dehydrogenase showed high activity even at low glucose concentrations.

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Jones, Victor Arnold Shivas. "The genetic control of rhizoid development in the liverwort Marchantia polymorpha." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:fd764164-55da-4b71-8397-f5a9e0f6ac4c.

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The first land plants faced a harsh terrestrial environment when they emerged from the water over 470 million years ago, and one of the key adaptations that allowed them radiate across the land was the development of a rooting system. To investigate the genetic mechanism that controlled the differentiation of rooting cells in ancient land plants, I carried out a mutant screen to identify genes that regulate rhizoid development in the liverwort Marchantia polymorpha, a member of the earliest-diverging lineage of land plants. I used insertional mutagenesis to generate a population of 105,000 lines from which I selected 61 mutants with defects in rhizoid development, and identified 10 genes that are part of the network of genes that influence the differentiation and growth of rhizoids. Eight of these are late-acting genes that are required for the elongation of rhizoids by tip growth, while two are transcription factors that direct early events in the adoption of rhizoid fate. I identified the bHLH transcription factor MpROOT HAIR DEFECTIVE 6-LIKE1 (MpRSL1) as a key regulator of rhizoid differentiation, as gain-of-function mutations in MpRSL1 cause rhizoids to develop in ectopic locations. The homologues of MpRSL1 in the angiosperm Arabidopsis and the moss Physcomitrella control the differentiation of their root hairs and rhizoids, respectively, which suggests that a gene regulatory network that included RSL genes controlled the development of filamentous rooting cells in the last common ancestor of all land plants. I also identified MpWIP, which encodes a member of a plant-specific family of zinc finger proteins, as a putative regulator of the development of both rhizoids and the cells of the air pore complex, a second specialized epidermal cell type. WIP genes have not been implicated in the control of rooting cell development in other species, so this role in Marchantia may be either inherited from the earliest land plants or a derived character. This work demonstrates the suitability of M. polymorpha as a subject for large-scale mutageneses and screens for gene discovery. The genes I have found to be involved in rhizoid development indicate that the last common ancestor of all land plants already possessed a gene regulatory network that controlled the development of rooting cells, and that at least some of its components, such as RSL genes, have been conserved in its descendents since the divergence of the liverworts and other land plants.

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Mota, Kelly Samara de Lira. "Atividade antifúngica do óleo essencial de Thymus vulgaris L. e fitoconstituintes contra Rhizopus oryzae e Rhizopus microsporus: interação com ergosterol." Universidade Federal da Paraíba, 2014. http://tede.biblioteca.ufpb.br:8080/handle/tede/6819.

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Made available in DSpace on 2015-05-14T13:00:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 7083796 bytes, checksum: 2aa6f174655d082d78cc059fc1eef2e0 (MD5) Previous issue date: 2014-03-11 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Mucormycoses are infections that have high rates of morbidity and mortality. They show high resistance to antifungal agents, and there is a limited therapeutic arsenal currently available, therefore, there is a great need to give priority to testing therapeutic agents for the treatment of mucormycosis. Along this line, the use of essential oils and phytoconstituents has been emphasized as a new therapeutic approach. The objective of this work was to investigate the antifungal activity of the essential oil (EO) of Thymus vulgaris, and its constituents thymol and p-cymene against Rhizopus oryzae and Rhizopus microsporus, through microbiological screening, determination of minimal inhibitory concentration (MICs) and minimal fungicidal concentration (MFCs), effects on mycelial growth and germination of sporangiospores, fungal morphology and interaction with ergosterol. Also was evaluated the preclinical acute toxicity in mice. In microbiological screening the T. vulgaris essential oil showed antifungal potential against resistant strains of R. oryzae.The MIC of EO and thymol varied 128 512 μg/mL, but the MFC of EO and thymol varied 512 1024 μg/mL and 128 1024 μg/mL, respectively. The results also showed that EO and thymol significantly inhibited mycelial development and germination of sporangiospores of both species of Rhizopus. Investigation of the mechanism of antifungal action showed that EO and thymol interact with ergosterol. These data indicate that EO of T. vulgaris and thymol possess strong antifungal activity, which can be related to their interaction with ergosterol, supporting the possible use of these products in the treatment of mucormycosis. In preclinical acute toxicology the doses of 125, 250, 500 and 1000 mg/kg intraperitoneally (i.p.) showed depressive activity on the central nervous system (CNS). In addition to these parameters was observed that the doses of 125 and 250 mg/kg did not change the body and organs weight of the animals, but it was observed change some of the hematological parameters of the mice. The EO showed DL50 of 250 mg/kg for male and 459.6 mg/kg for female; however the thymol showed DL50 of 222.3 mg/kg for male and 1551 mg/kg for female. These data indicate that EO of T. vulgaris and thymol possess strong antifungal activity, which can be related to their interaction with ergosterol. As mucormicoses são infecções que possuem elevadas taxas de morbidade e mortalidade, limitado arsenal terapêutico, devido a resistência aos antifúngicos. Portanto, existe uma significativa necessidade de priorizar, testar e aplicar melhorias terapêuticas para o tratamento das mucormicoses. É nesse contexto, que os óleos essenciais e fitoconstituintes vem se destacando como uma nova abordagem terapêutica. O objetivo deste trabalho foi investigar a atividade antifúngica in vitro do óleo essencial (OE) de Thymus vulgaris L. e de seus componentes majoritários (timol e p-cimeno) contra Rhizopus oryzae e Rhizopus microsporus, através da triagem microbiológica, da determinação da concentração inibitória mínima (CIM) e fungicida mínima (CFM), avaliação dos efeitos dos fitoconstituintes no crescimento micelial, na germinação dos esporos fúngicos, na morfologia fúngica e interação com ergosterol. Também foi avaliada a toxicidade pré-clínica aguda em camundongos. Na triagem microbiológica o óleo essencial de T. vulgaris apresentou um dos melhores perfis antifúngicos contra cepas resistentes de R. oryzae. A CIM dos produtos variou entre 128-512 μg/mL, já as CFMs do óleo essencial e timol variaram entre 512-1024 μg/mL e 128-1024 μg/mL, respectivamente. Os resultados também mostraram que tanto o OE como o timol inibiram significativamente o desenvolvimento micelial e a germinação de esporos de ambas as espécies de Rhizopus. Em seguida foi mostrado que os produtos testados alteram a morfologia de R. oryzae e R. microsporus. Na investigação do mecanismo de ação antifúngica foi evidenciado que o OE e o timol interagem com o ergosterol, esterol presente na membrana dos fungos. No ensaio toxicológico pré-clínica agudo, as doses de 125, 250, 500 e 1000 mg/kg via intraperitoneal (i.p.) apresentaram atividade depressora do sistema nervoso central (SNC). Adicionalmente a estes parâmetros foi evidenciado que o OE e o timol nas doses de 125 e 250 mg/kg não promoveram alterações significativas na evolução ponderal e peso dos órgãos dos camundongos. Entretanto, ambas as doses das drogas-teste alteram alguns parâmetros hematológicos dos camundongos. Após 72 h de observação o OE apresentou DL50 estimada em 250 mg/kg para camundongos machos e 459,6 mg/kg para as fêmeas. Já o timol apresentou DL50 estimada em 222,3 mg/kg para os machos e 1551 mg/kg para as fêmeas. Estes dados indicam que o óleo essencial de T. vulgaris e timol, apresentam forte atividade antifúngica, que pode estar relacionada com a interação com ergosterol e consequentemente lise de membrana.

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Opalka, David W. "Carbohydrate status of in vitro grown trillium rhizomes." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 0.64 Mb., 101 p, 2006. http://wwwlib.umi.com/dissertations/fullcit/1432293.

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Ismoyo, Fenny. "Biochemical changes associated with Rhizopus fermentation of soybean." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22743.

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The conversion of soybeans to tempe is achieved through fermentation by Rhizopus. This fermentation process leads to hydrolysis of both proteins and lipids. The present work investigated certain biochemical changes which accompany the conversion of soybeans to tempe. The contents of non-protein nitrogen and free $ alpha$-amino nitrogen increased from 2.34 to 15.14%, and 2.03 to 5.22%, respectively after 48 h fermentation. SDS electrophoresis showed that a substantial quantity of the proteins in raw soybeans were hydrolysed by the Rhizopus to low molecular species (molecular weight $<$13,000 Daltons). Trypsin inhibitor activity found in tempe was lower than that of soybean and soaked soybean (an intermediate step in tempe preparation). The protein digestibilities of tempe and soaked soybean were higher than that of soybean. Reversed phase HPLC showed that the peptide separation profile of tempe was different from that of soybean and soaked soybean. The ESI/MS of the RP-HPLC fractions gave molecular weight of soybean peptides ranging from 1962 Da to 22,699 Da and tempe peptides ranging from 569 Da to 16,688 Da. The fatty acid compositions of tempe, soybean and soaked soybean were similar; relatively high levels of linoleic acid followed by oleic, linolenic and stearic acids were found. The acid values increased from 1.49 to 11.42 during the fermentation of soybeans. The total soluble carbohydrate contents of soybean, tempe and soaked soybean as well as the types and quantities of individual sugars were similar. The fermentation of soybean by Rhizopus had only a minor effect on the proximate composition of soybean; however, the soybean and fungal enzymes contributed primarily to changes in protein composition.

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Tanti, Rose-Marie. "Hémisynthèse des irones à partir de rhizomes d'iris." Aix-Marseille 3, 1990. http://www.theses.fr/1990AIX30050.

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Une nouvelle methode de preparation des irones est decrite. L'oxydation par le permanganate de potassium dans les conditions de transfert de phase de l'extrait lipidique de rhizomes frais d'iris pallida permet d'obtenir plus de deux grammes d'irones par kilogramme de rhizomes poids sec, ce qui correspond a environ cinq fois le rendement obtenu par la methode traditionnelle. De plus, le melange des irones forme est analogue a celui de l'absolue d'iris actuellement commercialisee. Les conditions operatoires optimales de cette reaction ont ete determinees: duree de la reaction, quantite d'oxydant, choix et quantite de catalyseur. L'etude de l'oxydation de differents melanges d'irones a permis de mettre en evidence une difference de reactivite de chacun des isomeres qui les composent. Des methodes de separation et de dosage des precurseurs des irones sont proposees. Elles constituent les etapes cles d'un test permettant d'evaluer la qualite d'un lot de rhizomes vis-a-vis de la production des irones

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Tobin, John M. (John Michael). "The uptake of metal ions by rhizopus arrhizus biomass /." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=73999.

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Lhomme, Bibiane. "Production en masse du champignon filamenteux Rhizopus arrhizus et études des capacités de biosorption du mycellium à l'égard du cadmium." Grenoble 1, 1990. http://www.theses.fr/1990GRE10089.

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L'optimisation des conditions de culture du champignon filamenteux rhizopus arrhizus a ete etudiee afin de permettre une production importante de biomasse, couplee a une consommation maximale de saccharose. Dans les conditions de culture retenues, la biomasse produite en 5 jours est de 10,8 grammes par litre. Les concentrations en saccharose et en carbone organique dans le surnageant diminuent de 77 et 58% respectivement. Ces performances peuvent etre ameliorees en faisant croitre le micro-organisme sur un film liquide. La production est alors de 15,5 grammes de mycelium par litre de milieu au bout de 5 jours et les concentrations en saccharose et carbone residuels diminuent de 97 et 77%. Ces resultats plus performants seraient dus a une meilleure assimilation carbonee consecutive a un apport plus important en oxygene. Dans un deuxieme temps, la fixation du cadmium sur la biomasse a ete analysee. La capacite du mycelium brut est de 25 milligrammes de cadmium par gramme de poudre, comparable aux performances d'une resine echangeuse d'ions. Elle peut etre amelioree d'un facteur 5 apres traitement alcalin. La chelation et la precipitation sont les mecanismes principaux dans l'adsorption de metaux sur un tel biosorbant. Le ph joue un role essentiel que ce soit dans l'etape d'adsorption ou de disorption. Ainsi une regulation du ph a 7,5 permet d'ameliorer la capacite de fixation de 30%, et son maintien a 4 est suffisant pour eluer 85% du cadmium fixe, sans denaturation du support qui peut alors etre recycle. Ces observations et resultats permettent de proposer differents procedes d'epuration envisageables en milieu industriel

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Dedeoglu, Didem. "Purification And Characterization Of Hexokinase Isoenzymes From Rhizopus Oryzae." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12608262/index.pdf.

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ABSTRACT PURIFICATION AND CHARACTERIZATION OF HEXOKINASE ISOENZYMES FROM Rhizopus oryzae Dedeoglu, Didem MS., Department of Biotechnology Supervisor: Prof.Dr. Haluk Hamamci Co-supervisor: Dr. Seyda A&ccedil ar February 2007, 116 pages Glycolysis is the central metabolic pathway for living organisms. Its regulation is important for the yield of the end products which are industrially important. These end products, like lactic acid produced by Rhizopus oryzae, are industrially important. Rhizopus oryzae is a filamentous fungus producing lactic acid and ethanol. The lactic acid yield of R. oryzae is low (&amp #61566 70 %) compared to that of lactic acid bacteria (&amp #61502 95 %) still it is noteworthy because R. oryzae produces only the L (+) form of lactic acid which can be metabolized in the human body. The yield of an industrial process should be high for the feasibility of the production of a particular product. If a way can be found increase the flux through the glycolysis the yield of lactic acid may increase as well. Keeping this in mind we wanted to focus on the first step of glycolysis, hexokinase of R. oryzae. Hexokinase catalyzes the reaction that converts glucose to glucose-6-phosphate. In this study for the first time the two isoenzymes of hexokinase of R. oryzae were purified and characterized by biochemically and kinetically Hexokinase has two isoenzymes. The purified enzymes (isoenzymes1 &amp isoenzymes2) obeyed Michealis-Menten Kinetics. The Km value of purified isoenzyme 1 is 0.16 mM and isoenzyme 2, 0.21 mM at pH 7.70 for glucose. The Km value of isoenzyme1 for fructose was 28.8 mM. Essentially isoenzyme 2 can not utilize fructose. None of the isoenzymes were inhibited by trehalose-6-phophate.The monomer moleculer weight of isoenzymes were estimated SDS PAGE analysis. There were two different values for molecular weight of isoenzmye 1 62.9 and 42.5 kDa and two values for isoenzyme 2 56.2 and 41.6 kDa

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Haghayegh, Jahromi Neda, and Gheinani Ali Hashemi. "RNA Silencing of Lactate Dehydrogenase Gene in Rhizopus oryzae." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20404.

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RNA silencing with direct delivery of siRNA has been used to suppress ldhA gene expression in filamentous fungus Rhizopus oryzae. Here, for the first time we show that, introducing small interfering RNA which consequently forms silencing complexes can alter the gene expression and we report a significant reduction of lactic acid production for isolates containing short (25 nt) synthetic siRNA. In all samples lactic acid production was reduced comparing with wild types. The average concentration of lactic acid production by Rhizopus oryzae during batch fermentation process where glucose has been used as a sole carbon source, diminished from 2.06 g/l in wild types to 0.36 g/l in knockdown samples which signify 5.7 times decrease. Interestingly, the average concentration of ethanol production was increased from 0.38 g/l in wild types to 0.45 g/l in knockdown samples. In some samples we were able to report even a 10 fold decrease in lactic acid production. Since R.oryzae is capable to assimilate a wide range of carbohydrates hydrolysed from lignocellulosic material in order to produce many economically valuable bulk material such as ethanol, these results suggest that RNA silencing is a useful method for industrial biotechnology to be applied in fungus Rhizopus oryzae in order to trigger the metabolism and gene expression toward a desired product.

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Rangarajan, E. S. "Purification and characteristics of extracellular nuclease from rhizopus stononifer." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2001. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2302.

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Deshpande, R. A. "Ribonuclease Rs from rhizopus stolonifer: structural characteristics and immobilization." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2001. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2301.

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Policarpo, Lucas Makrakis. "Estudo de equilíbrio e cinética da biossorção de cobre (II) por Rhizopus Microsporus." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-13072016-162516/.

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A poluição relacionada a metais pesados tem recebido uma atenção especial devido a sua alta toxicidade, não biodegradabilidade e tendência de acumular-se na cadeia alimentar. Apesar disso, metais pesados também são considerados recursos valiosos, portanto a sua remoção em conjunto com a sua recuperação torna-se ainda mais importante. Este caso aplica-se aos rejeitos de mineração de cobre, os quais oferecem a possibilidade de recuperação do metal e de sua contenção de maneira segura do meio ambiente. Tais rejeitos se caracterizam por ocuparem enormes áreas inundadas e abrigarem soluções diluídas de cobre (II), porém, muitas vezes, acima dos limites seguros. Diversos processos tradicionais de tratamento mostram-se disponíveis para remover o cobre de tais soluções, no entanto, em certas aplicações eles podem ser ineficientes ou muito onerosos. Nesse contexto, a biossorção é uma alternativa interessante. Nesse processo, certos microrganismos, como fungos, bactérias e algas, ligam-se passivamente ao cobre na forma íons ou outras moléculas em soluções. No presente trabalho foi avaliado o potencial de biossorção de íons cobre (II) pela biomassa do fungo Rhizopus microsporus, coletado e isolado da área de rejeitos da Mina do Sossego, na região norte do Brasil. Isotermas de biossorção foram determinadas experimentalmente em bateladas sob temperatura de 25°C, agitação de 150 rpm, concentração de biomassa de 2,0 a 2,5 g/L e tempo de contato mínimo de 4 horas. O pH mostrou ser um fator importante no equilíbrio da biossorção, sendo o valor máximo da capacidade de biossorção de 33,12 mg de cobre / g biomassa encontrado em pH 6. Valores sucessivamente menores são encontrados pela acidificação da solução, sendo o pH 1 considerado adequado para o processo de dessorção, correspondendo a uma capacidade de biossorção de 1,95 mg/g. Modelos de adsorção de Langmuir e de Freundlich ajustaram-se adequadamente às isotermas tanto com pH controlado quanto não controlado. Foi constatado que a troca iônica é um dos mecanismos envolvidos na biossorção do cobre com Rhizopus microsporus. Tanto o modelo de pseudo-primeira ordem quanto o de pseudo-segunda ordem ajustaram-se aos dados cinéticos da biossorção, sendo que o equilíbrio ocorre em aproximadamente 4 horas. A biomassa conservou a capacidade de biossorção ao operar repetidamente em três ciclos de sorção-dessorção. A biomassa viável e a morta não apresentaram diferença estatisticamente significativa na capacidade de biossorção. Heavy metal pollution has been receiving a special attention because of the high toxicity of these metals, by their non-biodegradability and by their tendency to accumulate throughout the food chain. Nevertheless, heavy metals are also considered valuable resources, hence their recovery and recycle assumes even greater significance. This is the case of copper mining tailings, which offer the possibility of metal recovery while it must be safely contained from the environment. These wastes are characterized by occupying huge flooded areas with very dilute copper (II) solutions, however, in many cases above safe limits. Various traditional treatment methods are available to remove copper from such solutions; however, for certain applications they may be either ineffective or too costly. In this context, biosorption becomes an interesting alternative. In this process, certain microorganisms such as fungi, bacteria and algae, passively bind to the copper ion or other molecules in solution. In the present study the biosorption potential of copper (II) by the fungal biomass of Rhizopus microsporus, collected and isolated from the tailings area of Sossego mine, located in the northern region of Brazil, has been evaluated. Biosorption isotherms have been experimentally determined by batch experiments at a temperature of 25C, agitation speed of 150 rpm, biosorbent concentration in the range of 2.0 to 2.5 mg/L, and contact time of at least 4 hours. The pH has been found to be a determining factor for the sorption equilibrium, a maximum sorption capacity of 33.12 mg copper / g biomass being found at pH 6. Successively smaller values have been found by the acidification of the solution. A pH value of 1 has been considered adequate for the desorption process, which correspond to a biosorption capacity of 1,95 mg/g. Both Langmuir and Freundlich adsorption models fitted well to equilibrium data using both pH methodologies, however the determination coefficient is slightly higher for the former model. It has been found that ion exchange is one of the mechanisms involved in copper (II) biosorption by Rhizopus microsporus. Both pseudo-first and pseudo-second order models have fitted well to biosorption kinetic data. Equilibrium approaches within approximately 4 hours. The biosorbent has proved to maintain its sorption efficiency after three regeneration cycles. Viable and dead biomasses have not exhibited statistically significant difference in sorption behavior.

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Roger, Benoît. "Contribution à l'étude des rhizomes, huiles essentielles et extraits d'Iris germanica L. Et d'Iris pallida Lam. Du Maroc." Nice, 2010. http://www.theses.fr/2010NICE4084.

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Ce mémoire est consacré à l’étude des rhizomes, huiles essentielles, et extraits d’Iris germanica L. Et d’I. Pallida Lam. Du Maroc. Une méthode de dosage direct des irones dans les rhizomes par HS-SPME/GC a tout d’abord été développée et comparée à une méthode de dosage plus classique (extraction solide / liquide suivie d’une quantification par GC) avant d’étudier l’évolution de la teneur en irones en fonction de la durée de stockage des rhizomes. L’étude de la composition chimique du résinoïde d’Iris germanica a ensuite été réalisée. Elle révèle notamment la présence dans le résinoïde de flavonoïdes, d’iridals, d’esters d’iridals, d’irones, d’acides gras, de stéroïdes, d’alcanes et de glucides. La composition chimique des résinoïdes d’Iris pallida a également été comparée ainsi que celle de résinoïdes d’Iris pallida obtenues à partir de rhizomes provenant de différentes origines géographiques. Cette étude a conduit à l’identification de trois isoflavones caractéristiques de l’Iris germanica (la nigricanine, l’iriflogénine et l’irisolidone) et de quatre composés caractéristiques de l’Iris pallida permettant également de distinguer l’origine géographique des rhizomes (l’iriflophénone, la 2,6,4’-trihydroxy-4-méthoxybenzophénone, la 8-hydroxyrigénine et la 2,3-dihydrorigénine). La composition chimique d’autres extraits d’Iris germanica (absolue, extrait éthanolique et extraits au CO2 supercritique) a également été comparée à celle du résinoïde. Enfin, la distillation et la qualité des différents beurres d’Iris du Maroc (Iris germanica et Iris pallida) ont été étudiés ainsi que la valorisation des sous-produits de la distillation. Nous contribuons ainsi à une meilleure connaissance des rhizomes, huiles essentielles et extraits des différents iris cultivés au Maroc This report is dedicated to the chemical study of rhizomes, essential oil, and extracts of Iris germinaca L. And Iris pallida Lam. From Morocco. A method of direct quantification of irones in rhizomes by HS-SPME / GC is presented first and compared with a classical method (solid / liquid extraction followed by quantification by GC) before studying the evolution of the irones content according to the storage time of rhizomes. The study of the chemical composition of Iris germanica resinoid is then presented. It reveals the presence in the resinoid of flavonoids, iridals, iridals esters, irones, fatty acids, steroids, alkanes and carbohydrates. The comparison of Iris germanica and Iris pallida resinoids is also presented as well as that of iris pallida resinoid obtained from rhizomes resulting from various geographic origins. This study led to the identification of four characteristics compounds of the pallida species : the 2,6,4-‘’trihydroxy-4-methoxybenzophenone, the 8-hydroxyirigenine, the 2,3-dihydroirigenine and the iriflophenone. These four compouds also allow distinguishing Iris pallida resinoids obtained from rhizomes of four geographic studied origins (Morocco, Italy,France and China). The chemical composition of others Iris germanica extracts (absolute, alcohol extract and supercritical CO2 extract) is also presented. Finally, the distillation and the quality of the butters of iris from Morocco is presented (Iris germanica and Iris pallida) and a possibility of valuation of the distillation by-products is proposed. In this way, we contribute to a better knowledge of rhizomes, essential oil and extracts of vaious iris cultivated in Morocco

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Hamrlová, Romana. "Studie interakcí mezi lipázou a uhlíkatým nosičem." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217046.

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Tématem diplomové práce je imobilizace lipáz a konkrétně studium interakcí mezi lipázou a nosičem na bázi uhlíku. Lipáza izolovaná z kmene Rhizopus arrhizus byla adsorbována přímo na různé typy grafen oxidu (a1, a, b, c a d) a na grafen oxid typu a1 modifikovaný poly(ethylenglykolem), PEG-a1. Enzym adsorbovaný na nosič a1 byl následně sesítěn pomocí glutaraldehydu a vzorek byl označen jako GA(RA-a1). Vliv hydrofobního charakteru povrchu nosiče na účinnost imobilizace byl potvrzen vyšší úchovou počáteční aktivity enzymu imobilizovaného na více hydrofobním nosiči (nižší koncentrace polárních skupin) i při vyšší koncentraci rozpustného enzymu v roztoku. Stanovení enzymové aktivity bylo provedeno spektrofotometricky za použití p-nitrofenyl laurátu (p-NPL) jako substrátu. Pro imobilizovaný a volný enzym byly stanoveny základní biochemické a kinetické parametry. Optimální pH kovalentně imobilizovaného enzymu bylo posunuto do více kyselého oblasti (pH 7-8) ve srovnání s volným enzymem, kdy bylo optimum dosaženo při pH 9. Tepelná stabilita imobilizovaného enzymu byla výrazně zlepšena v případě vzorku GA(RA-a1), kde bylo aplikován glutaraldehyd po adsorpci enzymu na nosič. Sesíťování adsorbovaného enzymu pomocí glutaraldehydu vedlo ke zlepšení tepelné stability vzorku, a to pravděpodobně v důsledku intermolekulárních kovalentních vazeb. Na základě měření stability enzymu při teplotě 4 C ve fosfátovém pufru bylo prokázáno značné zlepšení úchovy lipolytické aktivity imobilizovaného vzorku oproti volnému enzymu. Volný enzym ztratil více než 84 % své původní aktivity za 42 dní, zatímco imobilizovaný enzym na nosiči c si zachoval 100 % své původní aktivity. Nejlepší stabilitu enzymu při úchově měl nosič c, když si po 180 dnech stále zachoval 87 % své původní aktivity.

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Sparringa, Roy Alexander. "Growth and protein utilisation by Rhizopus oligosporus during tempe fermentation." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298415.

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Essamri, Majda. "Production, caractérisation et performances synthétiques d'une souche fongique : Rhizopus oryzae." Aix-Marseille 3, 1996. http://www.theses.fr/1996AIX30099.

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Notre etude avait pour objet la synthese biocatalysee par les lipases de cires en reacteur a lit fixe. Dans la premiere partie de notre travail nous avons etudie les caracteristiques physico-chimiques des deux lipases endogenes et exogene produites par rhizopus oryzae. Celles-ci presentant des proprietes analogues nous nous sommes plus particulierement interesses a la lipase endogene. Cette lipase presente en effet l'avantage d'etre immobilisee naturellement sur le mycelium et donc de pouvoir etre utilisee telle quelle en synthese et surtout d'etre relativement protegee des inhibiteurs tels que les solvants. L'etude multiparametrique des conditions de culture du champignon menee suivant la methodologie de la recherche experimentale, nous a permis d'obtenir un mycelium dote d'une activite lipasique elevee. Une etude de la cinetique de denaturation de la lipase mycelienne dans un environnement non aqueux a montre que cette lipase se comporte de facon analogue dans la plupart des solvants organiques a l'exception de l'hexane. Le schema de denaturation, obtenu a partir du modele cinetique etabli, met en evidence l'existence d'une forme enzymatique intermediaire plus stable mais moins active. La seconde partie de notre travail a ete la mise en application de la lipase mycelienne pour la synthese de cires. Le systeme utilise pour realiser ces syntheses est un reacteur a lit fixe. L'optimisation de la synthese du laurate de lauryle et de l'oleate de myristyle dans ce reacteur avec recyclage nous a permis d'obtenir des rendements de reaction respectifs de l'ordre de 92% pour le laurate de lauryle et de 95% pour l'oleate de myristyle apres 8 heures de reaction. Des essais de synthese de l'oleate de myristyle en reacteur continu ont conduit a un rendement de 95% apres 3 heures de reaction

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Zhang, Kun. "Fumaric Acid Fermentation by Rhizopus oryzae with Integrated Separation Technologies." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354729467.

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Jang, Geupil. "Functional analysis of class 1 RSL genes in caulonema and rhizoid differentiation of Physcomitrella patens." Thesis, University of East Anglia, 2011. https://ueaeprints.uea.ac.uk/35077/.

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Canet, Morral Albert. "Alcoholysis reaction study of biodiesel synthesis by recombinant Rhizopus oryzae lipase." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/386470.

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L’escalfament global i la contaminació medioambiental han promogut la recerca científica i polítiques governamentals per tal de desenvolupar i aplicar processos de producció més sostenibles, un ús més racional de l’energia i la implenetació de sistemes de reciclatge. En aquest sentit, els alquil èsters d’àcids grassos – coneguts com a biodièsel – suposen una alterntaiva sostenible i renovable al dièsel convencional, i en l’actualitat ja s’usa mesclat amb dièsel. El biodièsel s’obté per transesterificació d’olis vegetals o grasses animals amb un alcohol – normalment metanol. Després de la seva combustió, el diòxid de carboni resultant és fixat per les plantes mitajançant la seva fotosíntesi, i convertit a biomassa a partir de la qual es torna a obtenir oli per fabricar-ne biodièsel. Així, l’avantatge principal del biodièsel respecte el dièsel convencional és que el seu ús és un cicle tancat de carboni, fet que evita l’augment del carboni ambiental, i a més a més no presenta els futurs problemes d’esgotament dels combustibles fòssils. En un altre ordre de coses, l’ús d’enzims s’ha estès dins la indústria, principalment perquè els processos enzimàtics són més sostenibles i tenen menys consum energètic que els processos convencionals. Malgrat tot, l’elevat preu dels enzims limita encara el seu ús i per tant és necessària més recerca. La utilització de lipases per generar biodièsel és un exemple de l’ús d’enzims per substituir mètodes convencionals. A la natura, les lipases es troben als éssers vius i la seva funció és la hidròlisi dels greixos – és a dir, triacilglicerols –, obtenint àcids grassos lliures. Recentment, l’ús de les lipases s’ha explorat com a alternativa a l’actual mètode d’obtenció de biodièsel, degut a que té un consum d’energia inferior i també perquè les lipases poden sintetitzar biodièsel a partir d’un rang de matèries primeres més ampli. Aquesta tesi s’ha focalitzat a l’estudi de la lipasa de Rhizopus oryzae, expressada recombinantment a partir de Pichia pastoris, com a biocatalitzador d’alquil èsters d’àcids grassos. En primer lloc es va estudiar la inactivació de la lipasa causada pel metanol, fet el qual és un dels principals inconvenients en l’ús de les lipases, així com també l’efecte de l’aigua en aquesta inactivació; d’aquest primer estudi, se’n va concloure que l’aigua contrarresta l’efecte negatiu del metanol, encara que la seva presència incrementa la hidròlisi dels greixos en lloc de la seva transesterificació. La presència d’àcids grassos lliures a les matèries primeres és un inconvenient important pels mètodes químics actuals d’obtenció de biodièsel, mentre que les lipases poden dur a terme sense problemes la transesterificació amb presència d’àcids lliures, convertint-los també a biodièsel. Així, la segona part de la tesi va ser centrada en estudiar si aquests àcids grassos lliures poden tenir algun efecte sobre les lipases, concloent que no només no perjudiquen l’enzim, sinó que la seva presència redeix l’efecte negatiu del metanol. Degut a la varietat de components implicats a la transesterificació enzimàtica – tri-, di-, monoacilglicerols, àcids grassos lliures, alcohol, aigua i biodièsel –, es varen realitzar experiments per determinar el mecanisme de reacció de la transesterificació. Es va concloure, que el biodièsel s’obté enzimàticament per combinació de l’alcohòlisi directa dels greixos i l’hidròlisi dels greixos i la posterior esterificació dels àcids grassos alliberats. També és va determinar que la lipasa de Rhizopus oryzae no necessita l’activació interfacial, fenomen característic de les lipases. Finalment, es va fer un estudi comparatiu de l’especificitat de la lipasa respecte acilglicerols i alcohols, demostrant que l’enzim és molt més específic per 1-monooleïna que per trioleïna, i presenta més tolerància a l’etanol que el metanol. Global warming and environmental pollution have fostered scientific research and encouraged governmental policies to develop and implement greener production processes, a more rational energy usage and recycling life cycles. In that sense, fatty acid alkyl esters – commonly known as biodiesel – have emerged as a green and renewable alternative to conventional diesel and currently it is commercially used in blends with diesel. Biodiesel is obtained by transesterification of vegetable oils or animal fats with an alcohol – most often methanol. After its combustion, carbon dioxide is fixed and converted to new biomass by photosynthesis, from which biodiesel is again produced. Thus, the main advantage of biodiesel over diesel is that its production and utilisation is a closed carbon cycle, which does not contribute to increasing atmospheric carbon levels, and overcomes the future depletion of fossil fuels. Moreover, the employment of enzymes has become widespread within the industrial sector, especially because enzymatic procedures are greener and have less energy demand compared to traditional chemical ones. However, the high price of enzymes still limits their utilisation and further scientific research is needed. The use of lipases to produce biodiesel constitutes one example of the employment of enzymes to replace an existing chemical production process. In nature, lipases are found in living organisms, which use them to catalyse the hydrolysis of triacylglycerols – i.e. lipids –, obtaining free fatty acids after breaking ester bonds. In recent years, their employment in the synthesis of biodiesel has been explored as a suitable alternative to the present chemical catalysis processes, due to its lower energy consumption and also because lipases can produce biodiesel from a larger variety of initial raw materials, compared to conventional process. This dissertation has been focused on the study of the Rhizopus oryzae lipase, expressed recombinantly by Pichia pastoris, as biocatalyst to synthesise fatty acid alkyl esters – Rhizopus oryzae lipase and recombinant Rhizopus oryzae lipase are referred to in the present booklet as ROL and rROL, respectively. Initially, methanol inactivation of the lipase, which remains the main drawback for the employment of lipases in biodiesel production, and the effect of water on this inactivation were investigated, concluding that water can buffer methanol’s negative effect on lipase, although it increases the hydrolysis of triacylglycerols. The presence of free fatty acids in the initial raw material is a major obstacle in conventional chemical biodiesel production, whereas lipases can handle perfectly free fatty acids, esterifying them to biodiesel. Thus, in the second part of the thesis the effect of free fatty acids on the lipase was also studied, concluding that not only do they not represent a problem for enzymatic biodiesel production, but also their presence reduces lipase inactivation by methanol. Due to the variety of compounds present throughout the lipase catalysis – tri-, di-, monoacylglycerols, free fatty acids, alcohol, water and biodiesel –, experiments to elucidate the whole transesterification reaction pathway were carried out. It was found that biodiesel was obtained by a combination of reactions, namely, direct triacylglycerol alcoholysis, triacylglycerol hydrolysis and free fatty acids esterification. It was also determined that rROL does not need the so-called interfacial activation, widely attributed to lipases. Finally, a comparative study of alcohol type and lipase specificity towards acylglycerols was also performed, demonstrating that rROL exhibits better tolerance to ethanol compared to methanol, and higher specificity towards 1-monoolein than triolein.

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Claesson, Sofia, and Rebecca Keckman. "Screening för exoenzymer från Rhizopus sp, Mucor indicus och Rhizomucor pusillus." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20960.

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Syftet med detta examensarbete är att finna exoenzymer från Rhizopus sp, Mucor indicus och Rhizomucor pusillus som kan användas vid förbehandling av organiskt avfall. Syftet är även att finna kolkällor/energikällor som tidigare inte använts inom forskningen i ämnet resursåtervinning vid Högskolan i Borås.För att kunna undersöka vilka kolkällor mikroorganismerna bryter ner odlas dessa upp på agarplattor innehållande minimal-medium samt en specifik kolkälla. Efter fyra dagars inkubering i 30oC studerar man agarplattorna för att se om mikroorganismerna vuxit eller inte. Kan man urskilja tillväxt har de lyckats bryta ner kolkällan samt producera motsvarande exoenzym. Då vissa resultat är oklara odlas mikroorganismerna även i skakflaskor, detta för att se om det är själva agarn i agarplattorna som påverkar mikroorganismernas tillväxt.Resultatet visar att vissa mikroorganismer växer bättre än andra. Detta kan bero på kolkällornas struktur, det vill säga om de är komplicerade eller ej. Studerar man mikroorganismerna var för sig skiljer de sig lite åt. Rhizopus sp växer bäst på galaktan vilket indikerar att den lyckas producera exoenzymet galaktas. Mikroorganismen saknar produktion av exoenzym när den odlas på kolkällorna cellulosa och kitin.Studerar man mikroorganismen Mucor indicus har den bäst tillväxt på galaktan och potatismjöl, vilket indikerar att den producerar exoenzymerna galaktas samt α-amylas. Den kolkällan som ger sämst tillväxt är cellulosa.Rhizomucor pusillus har bäst tillväxt på galaktan samt triglycerider och producerar då exoenzymerna galaktas och lipas. Den lyckas inte bryta ner cellulosa eller kitin och saknar då produktion av exoenzymen cellulas samt kitinas.Både xylan och galaktan testas var för sig för att kunna dra slutsatser om någon produktion av exoenzymet hemicellulas finns. Detta görs eftersom det inte finns tillgång till något rent ämne med hemicellulosa. Xylan testas även endast för exoenzymet xylanas.En av de kolkällorna som gett minst tillväxt för alla de testade mikroorganismerna var cellulosa. För att styrka detta resultat odlas mikroorganismerna upp i skakflaskor, där ingen tillväxt skedde. Den lilla tillväxt som erhölls på agarplattorna tyder på att mikroorganismerna växer med den tillsatta agarn som kolkälla och inte utnyttjar själva kolkällan. Varför mikroorganismerna inte kan tillgodo se sig cellulosa kan bero på att cellulosa har en komplex struktur som gör den svår att bryta ner utan förbehandling.

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Soberon, Lozano Maria Mercedes. "Estudo da propriedade de esterificação enantioseletiva da lipase de rhizopus sp." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256681.

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Orientador: Glaucia M. Partore Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Made available in DSpace on 2018-07-28T13:06:15Z (GMT). No. of bitstreams: 1 SoberonLozano_MariaMercedes_D.pdf: 17111705 bytes, checksum: 06478ceaa6a7e39816460e2443cdd3f8 (MD5) Previous issue date: 2001 Resumo: A propriedade enantioseletiva de uma lipase parcialmente purificada isoladade Rhizopussp foi estudadaatravésde umsistemade esterificaçãodo ácido láurico e o álcool quiral 2-octanol. Os experimentos foram realizados nas seguintes condições: proporção de substratos 1:1, 10 unidades hidrolíticas de lipase, presença de peneira molecular na reação, presença e ausência de hexano, e nas temperaturasde 45°C e 50°C respectivamente. Diferentes métodos foram utilizados para medir a enantioseletividade da lipase: reações usando o álcool 2-octanol na suas formas ( R ) e ( S ) puras, assim como a forma racêmica do álcool. Os experimentos foram analisados através de cromatografia gasosa convencional e cromatog rafia quiral. A enantioseletividadeda enzima foi estudada considerando os parâmetros de conversão de álcool ( 'dzeta' ), excesso enantiomérico do substrato residual ( ees ), excesso enantiomérico do produto ( eep ) e os valores de enantioseletividade (E ) obtidos com (ees) e (eep). Os resultadosmostraramque a enzima em estudo catalisou com maior eficiência a forma ( R )-enantiômero do 2-octanol do que a sua contraparte.Esta catálise enantioseletivada enzima aumentou com a presençade hexano, no sistemareacional. Os valores de ( 'dzeta' ), ( ees), ( eep), e ( E ) foram dependentesda temperaturana ausência de hexano no meio de reação. As constantescinéticas, constante de Michaelis-Menten ( Km), e velocidade máxima (Vmax), foram calculadaspara cada enantiômero observando-se diferenças significativas nos valores de Vmax.Os resultados obtidos com diferentes ácidos graxos mostraram uma melhor afinidade da enzima por o ácido octan6ico seguido do ácido láurico, indicando que o comprimento da cadeia alifática do ácido graxo é um fator importante na avaliação da esterificação enantioseletiva da lipase de Rhizopus sp. Abstract: The enantioselective property of partially purified lipase from Rhizopus sp, was tested by esterification of lauric acid with 2-octanol alcohol media. The experiments were performed in equal molar proportion of substrates, 10 hydrolytic activity units of lipase both, in organic solvent and organic solvent free media at 45°C and 50°C of temperature.The presence of molecular sieves in the reaction was important for the synthesis of ester by lipase. Different methods of determining the enantios electivity was used: reaction using single enantiomers as well as racemic mixture. Experiments were analyzed by capillary GC with conventional and chiral columns.The enantioselectivity of the enzyme was studied measuring degree conversion ('dzeta'), substrate enantiomeric excess (ees), product enantiomeric excess (eep)and enantiomeric ratio (E). The results showed that (R)-2-octanol was better substrate than (S)-2-octanol for the enzyme. This enantio specificity preference of Rhizopus sp lipase toward (R)-2-octanol increasedwith the presenceof hexane in the reaction.'dzeta', ees, eep and E values were dependent on temperature, and presence of solvent in reaction media. Km and Vmax values were calculated for each enantiomer observing that highest enantioselectivity was reflected in the largest variance of Vmax values. Results obtained with different fatty acids showed that long chain acyl fatty acids were better substrates (e.g: octanoic, lauric, myristic acids). So, the size of fatty acid is an important factor to be considered in the study of enantio selective esterification of Rhizopus sp lipase. Doutorado Doutor em Ciência de Alimentos

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Myers, Emily. "Of Rhizomes and Radio: Networking Indigenous Community Media in Oaxaca, Mexico." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20700.

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In the face of a shifting political climate in Latin America, movements for indigenous rights and autonomy are leveraging community media in new ways transcending the state-market binary. Through ethnographic research with Zapotec media producers in Oaxaca and the supportive organizations forming points of connection between radios and activists, I argue that the strength of the indigenous community media movement in Oaxaca, and its potential to build a movement to resist destructive state and market forces, is best explained by Gilles Deleuze and Felix Guattari’s concept of the rhizome, which portrays Oaxacan indigenous media as a map of heterogeneous interconnections defying structural hierarchies and binaries. With this picture of a rhizomatic media movement, I demonstrate how radios have paved the way for innovations, revealing creative ways that indigenous groups are connecting with each other and the outside world, while asserting agency in their interactions with the market and the state.

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Lopes, Danielle Branta. "Estudo da sintese de esteres de cera utilizando lipases em diferentes sistemas de reação." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256629.

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Orientador: Gabriela Alves Macedo Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Made available in DSpace on 2018-08-12T23:26:09Z (GMT). No. of bitstreams: 1 Lopes_DanielleBranta_M.pdf: 1927712 bytes, checksum: 4c84529dc29400d6dfb671ad68c0abc8 (MD5) Previous issue date: 2009 Resumo: O aumento da demanda por esteres obtidos naturalmente ou por processos biotecnologicos, para aplicacoes como aditivos em alimentos, cosmeticos, industrias farmaceuticas e de lubrificantes, faz necessario o desenvolvimento de catalisadores altamente especificos. Por esta razao, o uso de enzimas como catalisadores para a sintese de esteres de alto valor agregado vem sofrendo um rapido desenvolvimento, por proporcionar a possibilidade de obtencao de um produto atraves de um processo biologico. Embora destinada pela natureza para realizar a hidrolise de lipideos, lipases (E.C. 3.1.1.3) podem, sob condicoes apropriadas de reacao, promover a formacao de esteres atraves de reacoes de acidos e álcoois (esterificacao). Comparadas com processos quimicos ja realizados em uma escala industrial, reacoes enzimaticas ocorrem sob condicoes brandas (e ecologicamente mais favoraveis) apesar de poderem ser mais lentas. A grande vantagem e a especificidade apresentada pelas enzimas, que permite a formacao de derivados lipidicos, os quais nao sao facilmente preparados por processos laboratoriais convencionais. Neste trabalho, foi avaliado o desempenho de lipases microbianas e vegetais, nao-comerciais, e comparadas a uma lipase comercial, na síntese de esteres com possiveis propriedades emulsificantes, bem como a influencia das condicoes de reacao (concentracao de enzima, quantidade de agua, relacao molar dos substratos, tipos de meios reacionais, e cinetica) no processo de esterificacao. A etapa seguinte do estudo foi constituida de um planejamento experimental fatorial completo com o proposito de otimizar a producao do ester oleato de oleila, em meio livre de solvente organico, com a lipase de Rhizopus sp. selecionada por apresentar melhor desempenho catalitico. O mesmo estudo foi realizado tambem com a lipase comercial Lipozyme TL IMR, com finalidade comparativa. Os parametros reacionais estudados foram: razao molar entre os substratos (acido:alcool) e concentracao de enzima (% m/m em relacao a massa de reagentes). Destes ensaios, verificou-se melhor habilidade catalitica da lipase de Rhizopus sp. utilizando maior proporcao de alcool (2:1) e maior quantidade de enzima (9,8%). O mesmo foi observado com a enzima comercial Lipozyme TL IMR, a qual tambem apresentou maior producao de ester quando se fez uso de uma maior proporcao de alcool (3:1) e maior quantidade de enzima (7,0%). A porcentagem de esterificacao obtida pela lipase de Rhizopus sp. (93,1%) foi muito proxima a porcentagem obtida pela lipase comercial Lipozyme TL IMR (94,2%), evidenciando o grande potencial desta enzima nao-comercial na sintese do oleato de oleila. Por fim, foi realizada a caracterizacao parcial do ester quanto as atividades emulsificante e antimicrobiana. Resultados indicaram que o ester produzido neste trabalho demonstrou atividade emulsificante, porem esta nao foi tao alta quando comparada aos emulsificantes comerciais: Dodecil Sulfato de Sodio (SDS) e Tween 80. Observou-se tambem que o oleato de oleila nao foi capaz de inibir o crescimento microbiano de Bacillus subtilis, sendo assim, ate o presente momento, nao foi detectada atividade antimicrobiana para este ester Abstract: The increasing demand for esters obtained either through natural or biotechnological processes for use as food additives, cosmetics, pharmaceuticals and lubricants requires the development of highly specific catalysts for ester production. For this reason, the use of enzymes as catalysts for the synthesis of esters with high added value is undergoing rapid development. Although the main function of lipases in nature is to catalyze the hydrolysis of lipids, it can also be made to promote ester formation through the reaction of acids and alcohols (esterification) under specific reaction conditions. Although on an industrial scale enzymatic reactions may be longer when under milder and ¿greener¿ conditions compared to chemical processes. The great advantage of working with enzymes is their great specificity, which often allows for the preparation of lipid derivatives not easily obtained using conventional laboratory procedures. This work first evaluated a few variables affecting the synthesis of esters and the esterification process, namely the influence of: the use of commercial and non-commercial lipases of vegetable and fungi origin, reaction conditions, enzyme concentration, amount of water, molar ratio of substrates, types of organic solvents and reaction kinetics. In a second step, a complete factorial design was considered in order to optimize ester production in solvent-free systems using Rhizopus sp. lipase and Lipozyme TL IMR which were chosen because of their good performance. The reaction parameters chosen were molar ratio of substrates (acid:alcohol) and enzyme concentration. Lipase from Rhizopus sp. displayed the best catalytic activity at a molar ratio of 1:2 (acid:alcohol) and an enzyme concentration of 9.8%, whereas Lipozyme TL IMR had the best catalytic activity at a molar ratio of 1:3 and enzyme concentration of 7.0%. The rate of the sterification reaction yielded 93.1% using lipase from Rhizopus sp., very close to what it is obtained using commercial Lipozyme TL IMR that is 94.2%. This result shows a high potential for this non-commercial enzyme to be used as a catalyst for the oleyl oleate synthesis. The characterization of the ester included evaluation of emulsifier and antimicrobial activities. Oleyl oleate synthesized in this study proved to have lower emulsifier activity compared to commercial emulsifiers like sodium dodecyl sulfate (SDS) and Tween 80. Also, oleyl oleate did not inhibit the growth of Bacillus subtilis, thus no antimicrobial activity was observed for this substance Mestrado Mestre em Ciência de Alimentos

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Speranza, Paula 1976. "Production of special lipids by enzymatic interesterification of Amazonian oils and influence on the biological activity = Produção de lipídios especiais por interesterificação enzimática de óleos da Amazônia e influência na atividade biológica." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256645.

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Orientadores: Gabriela Alves Macedo, Ana Paula Badan Ribeiro Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Made available in DSpace on 2018-08-25T18:56:33Z (GMT). No. of bitstreams: 1 Speranza_Paula_D.pdf: 7220198 bytes, checksum: 8b6f66b900cc6f1b3afb59b799b23584 (MD5) Previous issue date: 2014 Resumo: Este trabalho teve como objetivos produzir, caracterizar e avaliar as propriedades antimicrobianas de bases lipídicas interesterificadas produzidas com óleos e gorduras da Amazônia utilizando diferentes lipases. No trabalho foram utilizadas duas misturas de óleo e gordura da Amazônia para a produção das bases lipídicas, sendo a primeira delas composta pelo óleo de buriti e a gordura de murumuru e a segunda composta pelo óleo de patauá e a estearina de palma. As reações de interesterificação foram catalizadas por duas lipases em três sistemas enzimáticos diferentes: lipase comercial Lipozyme TL-IM (Novozymes), lipase do micro-organismo Rhizopus sp. e a mistura de ambas as enzimas (comercial + Rhizopus sp.). Em ambas as misturas, os lipídios produzidos apresentaram diferentes características dependendo da enzima utilizada. Na mistura buriti: murumuru, a lipase de Rhizopus sp., além de ser específica pelas posições sn-1,3 do triacilglicerol, foi específica para o tipo de ácido graxo (insaturado). A lipase comercial foi específica apenas pelo tipo de ácido graxo (insaturado), enquanto que a utilização de ambas as enzimas não apresentou efeito sinérgico nesta mistura, os resultados obtidos foram intermediários aos obtidos com as enzimas individualmente. Na mistura patauá: estearina de palma, a lipase de Rhizopus sp. foi específica para o tipo de ácido graxo (insaturados), enquanto que a lipase comercial não demonstrou específicidade para esta mistura. No sistema catalisado por ambas as enzimas também não foi observado efeito sinérgico; os resultdos obtidos foram similiares aos obtidos com a enzima de Rhizopus sp. Para ambas as misturas, com os três sistemas enzimáticos, houve redução nos triacilglceróis trisaturados e tri-insaturados após as reações, com a formação de bases lipídicas predominantemente mono e di-insaturados. Estes lipídios formados mantiveram a concentração elevada de tocoferóis, carotenos e fenóis, indicando que a reação não influenciou na concentração dos compostos minoritários. Na avaliação antimicrobiana, as misturas antes e após a interesterificação foram emulsificadas, produzindo diferentes respostas. Emulsões produzidas com os lipídios interesterificados apresentaram menor tamanho de partícula e maior potencial antimicrobiano, exibindo efeito bactericida; emulsões produzidas com as misturas não-interesterificadas, apresentaram maior tamanho de partícula e menor potencial antimicrobiano, exibindo efeito bacteriostático. Portanto, as lipases foram capazes de catalisar as reações de interesterificação entre os óleos da Amazônia, indicando o potencial destes catalisadores nestas reações. As frações lipídicas obtidas apresentaram atividade antimicrobiana, o que abre precedentes para que estudos biológicos mais aprofundados sejam realizados Abstract: This study aimed to produce, characterize and evaluate the antimicrobial properties of interesterified Amazonian oils produced by different lipases. Two blends of Amazonian oils were subjected to enzymatic interesterification: the first one was composed by buriti oil and murumuru fat and the second one was composed by patauá oil and palm stearin. The interesterification reactions were catalyzed by two microbial lipases in three different enzymatic systems: one with a commercial lipase Lipozyme-TL-IM (Novozymes); a second with a lipase from the microorganism Rhizopus sp.; and the third with a mixture of both lipases (commercial and Rhizopus sp.). In both blends, depending on the enzyme used, the lipids produced presented different characteristics. In the buriti: murumuru blend, the lipase from Rhizopus sp. besides being specific for the sn-1,3 positions of triacylglycerol was specific for the type of fatty acids (unsaturated). The commercial lipase was specific only for the type of fatty acids (unsaturated), while the use of both enzymes showed no synergistic effect in this blend; the results were intermediate to those obtained with the individual enzymes. In the patauá: palm stearin blend, the lipase from Rhizopus sp. is specific for the type of fatty acid (unsaturated), while commercial lipase showed no specificity to this blend. In the system with both enzymes no synergistic effect was also observed; the results obtained were similiar to those obtained using only the enzyme from Rhizopus sp. In both blends, with the three enzymatic systems, there was a reduction in the proportions of triacylglycerols of the types trisaturated and tri-unsaturated after the reactions, with the formation of predominantly mono -and di- unsaturated lipids. These lipids produced maintained the high concentration of tocopherols, carotenoids and phenolics, indicating that the reaction did not influence the concentration of minor compounds. In the antimicrobial evaluation, the blends before and after interesterification were emulsified, producing different responses. Emulsions produced with interesterified lipids showed lower droplet size and higher antimicrobial activity (bactericidal effect); emulsions produced with non-interesterified blends showed larger droplet size and lower antimicrobial activity (bacteriostatic effect). Therefore, lipases were able to catalyze the interesterification reactions between Amazonian oils, indicating the potential of these catalysts in these reactions. Lipids obtained showed antimicrobial activity, which encourages more detailed biological studies Doutorado Ciência de Alimentos Doutora em Ciência de Alimentos

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Paula, Ariela Veloso de. "Reestruturação da gordura de leite por interesterificação enzimática empregando lipase imobilizada: otimização das condições reacionais e operacionais." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-05052015-200556/.

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As indústrias de alimentos têm procurado desenvolver novas tecnologias visando à obtenção de produtos mais saudáveis que possuam características sensoriais apreciadas pelo consumidor. Entre os produtos alimentícios, os óleos e gorduras podem ser destacados em função de sua importância nas características sensoriais. Neste contexto, o objetivo deste trabalho foi otimizar as condições reacionais e operacionais para reestruturação da gordura de leite por interesterificação enzimática com óleo de soja, empregando lipase de Rhizopus oryzae imobilizada em matriz híbrida orgânico-inorgânica sílica-álcool polivinílico (SiO2-PVA). Nas primeiras etapas do trabalho, o sistema imobilizado foi empregado na condução das reações em modo batelada em reator de tanque agitado, por 48 h. As condições reacionais que favoreceram a maximização do grau de interesterificação (GI), minimização do teor de ácidos graxos livres e obtenção de produto interesterificado com consistência na faixa ideal (200 a 800 g/cm2) foram: 65% de gordura de leite na mistura reacional, 500 unidades de atividade por grama de meio, 10% de umidade no derivado imobilizado e temperatura de reação de 45 ºC. Nessas condições, obteve-se um produto interesterificado com consistência de 385 gf/cm2. Em seguida, foram realizados testes de interesterificação da gordura de leite com óleo de soja em reator de tanque agitado operando em batelada com a adaptação de cesta (central ou lateral) no seu interior, para isolar o sistema imobilizado do contato com as partes mecânicas do agitador. A cesta na configuração central foi selecionada, uma vez que em 4h de reação permitiu a obtenção de um produto interesterificado com adequado valor de consistência (387 gf/cm2), mais elevado grau de interesterificação (8,01%) e mais baixo teor de ácidos graxos livres (4,61 %), além da maior facilidade no manuseio, se comparado à cesta lateral. Nos testes em reatores operando em modo contínuo, empregou-se a lipase de Rhizopus oryzae imobilizada em SiO2-PVA, por adsorção física. Foram efetuadas quatro reações em leito fixo, e avaliadas duas fontes comerciais distintas de gordura. A partir da interesterificação da gordura de leite oriunda de uma das marcas comerciais avaliadas, obteve-se um produto com consistência adequada (712,08 gf/cm2), em apenas 12 minutos. Finalmente, foram realizadas duas reações em leito fluidizado empregando-se a lipase comercial Novozym® 435 e a lipase de Rhizopus oryzae imobilizada em SiO2-PVA. Os resultados revelaram que a lipase de Rhizopus oryzae representa um biocatalisador com potencial para modificação da gordura de leite, uma vez que apresentou maior redução percentual (52,31 %) da consistência dos produtos em relação à mistura reacional, comparativamente aos resultados observados empregando-se Novozym® 435 (33,97 %) como biocatalisador. Os resultados obtidos foram satisfatórios e permitiram a determinação de condições de processo em diferentes tipos de biorreatores, contribuindo com o desenvolvimento de tecnologias nacionais de processos enzimáticos em escala industrial para a fabricação de produtos de interesse econômico e social. The food industries have been interested to develop new technologies to obtain healthier products with sensory characteristics appreciated by the consumer. Among food products, oil and fat could be highlighted due to their importance in sensory characteristics. In this matter, the purpose of this study has been to optimize the reaction and operational conditions to restructure fat of milk by enzymatic interesterification with soybean oil, using immobilized lipase of Rhizopus oryzae in organic-inorganic polysiloxane-polyvinyl alcohol (SiO2-PVA) hybrid matrix. Firstly, the immobilized system has been used in the reactions on batch mode in stirred tank reactor for 48 hours. The reaction conditions that allowed the maximization of the interesterification degree, the minimization of the free fatty acids content and to have an interesterified product with the consistency in the target range (200 to 800 g/cm2) were: 65% milk fat in the reaction mixture, 500 units of activity per gram of medium, 10% humidity in the immobilized derivative and reaction temperature of 45 ºC. Under these conditions, an interesterified product with 385 gf/cm2 consistency was obtained. Following, tests of interesterification of milk fat with soybean oil were carried out in stirred tank reactor in batch mode and with a basket (central or lateral) inside the vessel aiming to isolate the immobilized system of the contact with mechanical parts of the mixer. The basket in the central configuration has been selected because, in 4 hours of reaction, it allowed to obtain an interesterified product with an adequate value of consistency (387.00 gf/cm2), the highest interesterification degree (8.01%) and the lowest free fatty acids content (4.61%), besides an easy handling compared to the lateral basket configuration. In tests on reactors operating in continuous mode, Rhizopus oryzae lipase immobilized by physical adsorption in SiO2-PVA was used. Four reactions have been performed in packed bed reactor, and two different commercial sources of fat have been evaluated. In the interesterification of milk fat of one of the commercial marks evaluated, a product with adequate consistency (712.08 gf/cm2) was obtained in just 12 minutes. Finally, two reactions in fluidized bed have been performed using the commercial lipase Novozym® 435 and Rhizopus oryzae lipase immobilized in SiO2-PVA. The results showed the Rhizopus oryzae lipase is a biocatalyst with potential for modification of milk fat, considering its use resulted in a higher percentual reduction (52.31 %) of the products consistency in relation to the reaction mixture, comparatively to the observed when Novozym® 435 (33.97 %) was used as biocatalyst. The obtained results were satisfactory and allowed the determination of process conditions in different kinds of bioreactors, besides to contribute to the development of national technologies of enzymatic processes in industrial scale for the manufacturing of products of economic and social interest.

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Nunes, Gisele Fátima Morais. "Avaliação da interesterificação enzimática de misturas binárias e ternárias de gordura de leite com óleos de canola e castanha-do-pará nas propriedades do produto obtido." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-22082013-164341/.

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Este trabalho teve como objetivo avaliar o efeito da interesterificação enzimática da gordura de leite com óleos de canola e castanha-do-pará nas propriedades do produto alimentício obtido, empregando lipase de Rhizopus oryzae imobilizada em sílica-álcool polivinílico (SiO2-PVA) como catalisador. Considerou-se desejável a obtenção de um produto que, ao incorporar parte dos ácidos graxos insaturados e essenciais presentes nos óleos, apresentasse boa espalhabilidade sob temperatura de refrigeração. Na primeira etapa as propriedades das matérias-primas foram determinadas aplicando técnicas oficiais de análise e verificou-se que todas apresentaram características de acordo com a legislação brasileira para uso em produtos alimentícios. Em seguida, foram testados dois métodos (adsorção física e ligação covalente) para efetuar a imobilização da lipase selecionada em SiO2-PVA e os resultados obtidos indicaram a adequação do procedimento de adsorção física. As condições otimizadas para conduzir as reações de interesterificação enzimática de blendas binárias de gordura de leite e óleo de canola, e de gordura de leite e óleo de castanha-do-pará, foram determinadas por planejamento composto central (CCD) constituído de 11 experimentos. A influência das variáveis temperatura (45-65?C) e teor de gordura no meio reacional (50-80%) foi avaliada simultaneamente, considerando como variáveis-resposta o grau de interesterificação (GI) e a consistência dos produtos. Modelos empíricos que possibilitaram a seleção de condições para obtenção de produtos interesterificados com satisfatória espalhabilidade (consistência entre 200 e 800 gf/cm²) foram compostos e confirmados para cada caso. Para a blenda gordura de leite e óleo de canola, as condições selecionadas corresponderam a um meio contendo 65% de gordura e 35% de óleo e incubado a 45°C por 12 h. Nessas condições foram obtidos produtos com consistência de 700 gf/cm². No caso da blenda gordura de leite e óleo de castanha-dopará, produtos interesterificados que atendem o parâmetro desejado (200-800 gf/cm²) foram obtidos empregando-se um meio contendo 50% de gordura e 50% do óleo, incubados a 45°C por 24 h. Reações de interesterificação de blendas ternárias de gordura de leite, óleo de canola e óleo de castanha-do-pará foram também efetuadas de acordo com um planejamento de misturas, constituído de 17 experimentos visando avaliar a influência da proporção de cada componente da blenda na consistência do produto interesterificado. Na faixa de variação investigada, o uso de blendas contendo 56% de gordura de leite, 22% de óleo de canola e 22% de óleo de castanha-do-pará incubadas por 3 h a 45°C resultou em produtos interesterificados com satisfatória consistência e plasticidade (634 gf/cm²). O desempenho das reações enzimáticas conduzidas sob aquecimento convencional e não convencional (irradiação de micro-ondas) foi ainda avaliado para as blendas binárias nas condições preditas pelo planejamento composto central, não sendo observada interferência das micro-ondas na atuação da enzima, obtendo-se produtos interesterificados com valores similares de consistência. Os dados obtidos sugerem que o processo de interesterificação enzimática catalisado pela lipase de Rhizopus oryzae imobilizada em SiO2-PVA foi eficaz para a modulação das características de plasticidade dos produtos obtidos empregando tanto misturas binárias como ternárias. The objective of this work was to assess the effect of the enzymatic interesterification of milkfat with canola oil and Brazil nut oil on the properties of the resulting food product, using Rhizopus oryzae lipase immobilized on silica-polyvinyl alcohol (SiO2-PVA) as catalyst. The work was carried out considering as desirable to obtain a more spreadable product under domestic refrigerated conditions as well as enriched with unsaturated and essential fatty acids. Firstly, the properties of the raw materials were determined by applying official analysis techniques and results indicated that all raw materials were in agreement with the Brazilian legislation to food products. Then, two methodologies (physical adsorption and covalent binding) were tested for immobilizing the selected lipase on SiO2-PVA and physical adsorption was found to be the most suitable procedure. The optimized conditions to perform the enzymatic interesterification reactions of binary blends (milkfat and canola oil and milkfat and Brazil nut oil) were determined by central composite design (CCD), leading to a set of 11 runs. The influence of the variables, temperature (45-65°C) and the content of milk fat in the reaction medium (50-80%), was assessed simultaneously, taking the interesterification degree (ID) and consistency (10°C) as response variables. Empiric models were composed and confirmed for each case to establish conditions at which products with satisfactory spreadability (consistency in the range from 200 and 800 gf/cm²) can be obtained. For the milkfat and canola oil blend, the established conditions corresponded to a medium containing 65% of milk fat and 35% of oil, and lipase incubated at 45°C for 12 h. In these conditions, products with consistency of 700 gf/cm² were obtained. In the case of milkfat and Brazil nut oil blend, interesterified products with desirable parameter (200 and 800 gf/cm²) were obtained from reactions carried out with medium containing 50% of milk fat and 50% of oil, and lipase incubated at 45°C for 24 h. Interesterification reactions of ternary blends of milkfat, canola oil and Brazil nut oil were also carried out according to a mixture design with 17 runs to assess the influence of the mass proportion of each compound in the blend on the consistency of the interesterified products. In the range studied, the use of blends with 56% of milkfat, 22% of canola oil and 22% of Brazil nut oil and incubation at 45°C for 3 h resulted in products with satisfactory consistency and plasticity (634 gf/cm²). The performance of enzymatic reactions carried out under conventional and non-conventional (microwave irradiation) heating was also assessed for binary blends under the conditions predicted by the central composite design, and no interference of the microwave in the enzyme action was observed, resulting in interesterified products with similar values of consistency. The results obtained suggested that the process of enzymatic interesterification catalyzed by Rhizopus oryzae immobilized on SiO2-PVA was effective in modulating the plasticity properties of the products obtained using both binary and ternary blends.

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Lièvremont, Didier. "Interactions de trois micromycètes avec le pentachloronitrobenzène." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE18001.

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Inácio, Renata Gonçalves dos Santos. "Efeito do dibenzotiofeno - DBT (derivado do petróleo) no crescimento e na morfologia de rhizopus arrhizus UCP 402." Universidade Católica de Pernambuco, 2010. http://tede2.unicap.br:8080/handle/tede/900.

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Submitted by Biblioteca Central (biblioteca@unicap.br) on 2017-10-18T18:19:59Z No. of bitstreams: 1 dissertacao_renata_goncalves_santos_inacio.pdf: 1768781 bytes, checksum: 5fdfcec3f8878393182377f7f1dc5564 (MD5) Made available in DSpace on 2017-10-18T18:19:59Z (GMT). No. of bitstreams: 1 dissertacao_renata_goncalves_santos_inacio.pdf: 1768781 bytes, checksum: 5fdfcec3f8878393182377f7f1dc5564 (MD5) Previous issue date: 2010-06-14 The present work had as objective investigate the effect of dibenzotiofene - DBT (derived from oil) in the growth and morphology of Rhizopus arrhizus UCP 402. Had the increase of the use of the fossil fuels used for some industrialized countries, a serious environment problem aggravates due to quality of the reserves of the oil, in view of the amount of sulphur, and consequently, greater toxicity for the environment. In turn, the dibenzothiofene (DBT) is a composition heterociclic organossulfurated in the oil diesel, being considered a great fuel that cause ambient problems. The use of the DBT for R. arrhizus UCP 402 was evaluated from different concentrations of this composition, having observed itself the effect in kinetic of growth and the morphology, in the production of quitina and quitosana, as well as in the formation of toxic methabolits. The gotten results had indicated that R. arrhizus presents ability to grow in the different concentrations of the composition, however only, in co-metabolism, that is, in the glucose presence. A variation in the total protein text, quitina and quitosana for the action of the DBT was observed. The óptic microscopy evidenced variations in the morphology of R. arrhizus, also causing alterations in the ramification of hifas on standard. The products of the metabolism of the DBT had indicated that degradation of the composition for R. arrhizus occurred, whose methabolits had presented one accented inhibition of the germination of Cabbage of the 4 stations (oleracea Brassica to var. capitata). The carried through studies had demonstrated a great biotechnological potential of R. arrhizus in the process of degradation of DBT, being able to be used in the future in biorremediation processes. O presente trabalho teve como objetivo investigar o efeito do dibenzotiofeno – DBT (derivado do petróleo) no crescimento e na morfologia de Rhizopus arrhizus UCP 402. Com o aumento da utilização de combustíveis fósseis por vários países industrializados, um sério problema ambiental se agrava devido à qualidade das reservas do petróleo, tendo em vista a quantidade de enxofre, e conseqüentemente, maior toxicidade para o meio ambiente. Por sua vez, o dibenzotiofeno (DBT) é um composto organossulfurado heterocíclico presente no óleo diesel, sendo considerado um combustível que causa grandes problemas ambientais. A utilização do DBT por R. arrhizus UCP 402 foi avaliada a partir de diferentes concentrações desse composto, observando-se os efeitos na cinética de crescimento e morfologia do fungo, na produção de quitina e quitosana, como também na formação de metabólitos tóxicos. Os resultados obtidos indicam que R. arrhizus apresenta habilidade para crescer nas diferentes concentrações do composto, porém apenas, em co-metabolismo, isto é, na presença de glicose. Observou-se uma variação no teor de proteínas totais, em quitina e quitina pela ação do DBT. A microscopia ótica evidenciou variações na morfologia de R. arrhizus, causando também alterações no padrão de ramificação das hifas. Os produtos do metabolismo do DBT indicam que ocorreu degradação do composto por R. arrhizus, cujos metabólitos apresentaram uma acentuada inibição da germinação de Repolho das 4 estações (Brassica oleracea var. capitata). Os estudos realizados demonstram um grande potencial biotecnológico de R. arrhizus no processo de degradação de DBT, podendo ser empregado no futuro em processos de biorremediação.

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Soccol, Carlos Ricardo. "Physiologie et métabolisme de rhizopus en culture solide et submergée en relation avec la dégradation d'amidon cru et la production d'acide L (+) lactique." Compiègne, 1992. http://www.theses.fr/1992COMPD490.

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Les champignons filamenteux appartenant au genre Rhizopus présentent un grand intérêt dans différents domaines de l'industrie des biotechnologies. Ce travail concerne l'étude de la physiologie, de la croissance de Rhizopus ainsi que, son métabolisme et sa production d'acide L (+) lactique, en milieu liquide et solide. Il a été montré que la majorité des souches de Rhizopus tolèrent bien des concentrations de 5 à 10% de CO2. Par contre, à partir de 16 à 20% de CO2, un ralentissement de la vitesse de croissance est observé. Certaines souches peuvent se développer en anaérobiose. Le seigle s'est montré comme le meilleur substrat pour la production massive d'inoculum. La productivité maximale obtenue a été de 4,8 x 108 sporangiospores / jour et par g de matière sèche. La culture de Rhizopus en milieu solide, sur granules de manioc, nous a montré la capacité importante de certaines souches à dégrader l'amidon cru du manioc. La régulation du métabolisme à travers du contrôle du pH et de l'aération s'est révélée fondamentale pour la production d'acide L (+) lactique ou d'éthanol par Rhizopus. En aérobiose, dans un milieu tamponné avec CaCO3, le champignon produit en grande quantité l'acide L (+) lactique. Par contre, en anaérobiose, son métabolisme est dirigé vers la production d'éthanol. L'étude comparative entre la production d'acide L (+) lactique en bioréacteurs (BIOLA-FITTE 2L) et en milieu solide avec comme support la bagasse de canne à sucre a montré que : la concentration optimale de glucose en milieu liquide est de l'ordre de 120 g/l, par contre en milieu solide elle est de 180 g/l; la production maximale d'acide L (+) lactique en milieu liquide est de l'ordre de 94 g/l, par contre en milieu solide elle atteint à 137 g/l; la productivité en acide L (+) lactique en milieu liquide est de l'ordre de 1,38 g/l. H. , par contre en milieu solide elle est de 1,43 g/l. H; le rendement de la fermentation est de l'ordre de 77% soit en milieu solide, soit en milieu liquide. Ces résultats démontrent que la fermentation en milieu solide offre de nombreux avantages par rapport à la fermentation en milieu liquide. L'intérêt de la FS réside dans les faibles coûts de l'opération, les faibles dépenses d'énergie et dans l'obtention de fortes concentrations d'acide. Son application semble donc intéressante dans l'industrie pharmacologique, médicale et alimentaire.

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38

Ozer, Uyar Gulsum Ebru. "Cloning And Characterization Of Trehalose-6-phosphate Synthase Gene From Rhizopus Oryzae." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611025/index.pdf.

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In many organisms, trehalose protects against several environmental stresses, such as heat, desiccation and salt, probably by stabilizing protein structures and lipid membranes. Trehalose-6-phosphate synthase 1 (TPS1) is a subunit of trehalose synthase complex in fungi it plays a key role in the biosynthesis of trehalose. In this study, a TPS1 gene fragment in R. oryzae was cloned successfully by PCR with primers designed according to eight hypothetical proteins found from BLAST search which was performed by using S. cerevisiae TPS1 gene template. The full length of R. oryzae TPS1 gene (designated RoTPS1) was attained by RTPCR with primers specific to the 3&amp #8242 and 5&amp #8242 end of the RoTPS1 cDNA. The RoTPS1cDNA was composed of 2505 bps encoding a protein of 834 amino acids with a molecular mass of 93.8 kDa. The amino acid sequence has relatively high homology with the TPS1s of several other organisms. RoTPS1 was further characterized by transformation into S. cerevisiae tps1 mutant. In galactose media, the growth curves of wild type, tps1 mutant and transformant S. cerevisiae cells had a comparable pattern in general, tps1 mutant reached to a higher maximum cell concentration compared to the others and wild type had a slightly lower specific growth rate compared to the tps1 mutant and transformed cells. Trehalose levels of transformant and wild type cells were increased up to 37 mg/gdw in the stationary phase.

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39

Aryan, Fatemah Ali. "Immunology of the emerging human fungal pathogens Rhizopus oryzae and Pseudallescheria boydii." Thesis, University of Exeter, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603475.

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40

Penmatsa, Kiran Kumar, and Bharat Balu. "Construction of hpRNA expression vector for silencing a gene in Rhizopus oryzae." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16927.

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Depending on the previous research on LDHA gene silencing in Rhizopus oryzae CCUG 28959 through introduction of siRNA, a integral vector was constructed by inserting two copies of LDHA gene (by PCR cloning) in a fashion that it can express hpRNA in the transformed fungi, which will trigger the post transcriptional degradation of targeted mRNA through RNA degradation pathway which is known to be quelling in fungi.The vector was successfully designed with the LDHA gene, transformed in to the host organism, and also transferred to its progeny. This helps in maintaining stability of the transformed cell lines. This created vector will be advantageous at this point when compared to the use of siRNA for gene silencing, which is not a stable way. In the future, this vector can be used for down regulating other genes of interest in R. oryzae and can also be used for studying its effect on other metabolic pathways.In this study, Hygromycin resistance to the R. oryzae CCUG 28959 was shown at levels up to 1000 μg/ml, which has not been reported previously. Program: MSc in Resource Recovery - Industrial Biotechnology

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Acar, Seyda. "Biochemical And Genetic Studies On The Pyruvate Branch Point Enzymes Of Rhizopus Oryzae." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12604762/index.pdf.

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Rhizopus oryzae is a filamentous fungi which produces lactic acid and ethanol in fermentations. R. oryzae has numerous advantages for use industrial production of L-(+)-lactic acid but the yield of lactic acid produced on the basis of carbon consumed is low. Metabolic flux analysis of R. oryzae has shown that most of the pyruvate produced at the end of the glycolysis is channelled to ethanol, acetyl-CoA and oxaloacetate production. This study aimed to answer some questions addressed on the regulation of pyruvate branch point in R. oryzae and for this purpose biochemical characterisation of the enzymes acting at this branch point and cloning the genes coding for these enzymes have been done. Pyruvate decarboxylase was purified and characterised for the first time from R. oryzae. The purified enzyme has a Hill coefficient of 1.84 and the Km of the enzyme is 8.6 mM for pyruvate at pH 6.5. The enzyme is inhibited at pyruvate concentrations higher than 30 mM. The optimum pH for enzyme activity shows a broad range from 5.7 and 7.2. The monomer molecular weight was estimated as 59&plusmn 2 kDa by SDS-PAGE analysis. Pyruvate decarboxylase (pdcA and pdcB) and lactate dehydrogenase (ldhA and ldhB) genes of R. oryzae have been cloned by PCR-cloning approach and the filamentous fungi Aspergillus niger was transformed with these genes. The A. niger transformed with either of the ldh genes of R. oryzae showed enhanced production of lactic acid compared to wild type. Citric acid production was also increased in these transformants while no gluconate production was observed Cloning of hexokinase gene from R. oryzae using degenerate primers was studied by the use of GenomeWalker kit (Clontech). The results of this study were evaluated by using some bioinformatics tools depending on the unassembled clone sequences of R. oryzae genome.

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Vieira, Maricy Machado Cavalca. "Estudos da obtenção de esteres por lipase de Rhizopus sp LB-FEA-14." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256689.

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Orientador: Glaucia M. Pastore Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Made available in DSpace on 2018-07-24T22:11:50Z (GMT). No. of bitstreams: 1 Vieira_MaricyMachadoCavalca_M.pdf: 5802177 bytes, checksum: 014612537c661979ffe674b602d70a08 (MD5) Previous issue date: 1999 Resumo: Ésteres de ácidos graxos tem larga aplicação como emulsificantes em alimentos, cosméticos e produtos farmacêuticos. Além do seu efeito conservante, os ésteres podem ser utilizados como aromatizantes naturais na indústria alimentícia. Lipases são enzimas pertencentes a classe das Hidrolases que atua em ésteres de ácidos graxos e glicerol na interface óleo-água em um sistema insolúvel ou heterogêneo. Esta característica peculiar se deve ao fato de serem solúveis em água e atuarem em substratos insolúveis em água. O objetivo deste estudo foi verificar as condições ótimas de produção de ésteres em meio reacional aquoso e em solvente orgânico por lipase microbiana. Neste trabalho, foram selecionadas lipases de diferentes microrganismos para produção de ésteres. A lipase de Rhizopus sp FEA-LB-14 foi a enzima mais ativa para a produção de ésteres. As condições ideais para produção de ésteres de sacarose e ácido oléico foram com relação molar de 0,05mol/L:0,05mol/L, respectivamente em tampão acetato O,05M pH 5,6 à 40°C por um período de 96h, usando 4g/L de enzima bruta de Rhizopus sp. A mesma enzima mostrou melhor atividade para a produção de Butil Laurato, em solvente orgânico, frente a outros substratos. As condições ótimas de reação foram: relação molar de butanol e ácido láurico de 1: 1, em hexano, à temperatura de 50°C por 2 horas. A reação de esterificação entre glicerol e diferentes ácidos graxos foi examinada e verificou-se que a enzima esterifica o ácido láurico e glicerol com maior rendimento, produzindo mono, di e triglicerídeos Abstract: Fatty acid esters are widely applied as emulsifiers in food, cosmetics and pharmaceutical products. Besides their activity in inhibiting microbial growth, these esters can be used as natural flavouring in the food industry. Lipases are enzymes classified as Hidrolases, that act on fatty acid esters and glycerol, at the oil - water in interface, insoluble or heterogeneous systems. This special characteristic is due to its solubility in water and its action on water insoluble substrates. The objective of this work was to verify the optimum conditions for ester production by microbial lipase in an aqueous system and in an organic solvent. In this work, lipases from different microorganisms were selected for ester production. Rhizopus sp. FEA-LB-14 lipase was the most active enzyme found for the production of esters. For oleic acid esters of sucrose, the best conditions for production were obtained with a sucrose: oleic acid molar ratio of: 0.05 Mol/L: 0.05 Mol/L in 0.05 M acetate buffer pH 5.6 at 40°C for 96 hours, using 4g/L Rhizopus sp crude enzyme. Butyllaurate ester was the product with the highest yield, obtained by a lipase catalysed esterification of different fatty acids and alcohol. The optimum reaction conditions were: 1: 1 molar ratio of butanol and lauric acid in hexane at 50° C for 2 hours. The esterification reaction between glycerol and different fatty acid was examined. It was verified that the enzyme gives the greatest yields by esterifying lauric acid and glycerol, producing, monoglyceride, diglyceride and triglyceride Mestrado Mestre em Ciência de Alimentos

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Paiva, JosÃ RÃgis de. "Estudo do potencial biocatalÃtico do fungo Rhizopus stolonifer na biotransformaÃÃo de produtos naturais." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11544.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior Neste trabalho investigou-se o potencial biocatalÃtico do fungo Rhizopus stolonifer um fungo fitopatogÃnico em biotransformaÃÃes de metabÃlitos secundÃrios naturais Dois desses metabolitos, o diterpeno 3,12-dioxo-15,16-epoxi-4-hidroxicleroda-13(16),14-dieno e o derivado fenÃlico 6-gingerol foram biotransformados e seus respectivos produtos isolados e quantificados por CLAE A elucidaÃÃo estrutural dos produtos de biotransformaÃÃo pelo fungo Rhizopus stolonifer foram realizadas por anÃlise dos espectros de RMN 1H RMN 13C RMN 13C-DEPT 135 IV e EM Identificou-se que os produtos obtidos eram provenientes de uma biorreduÃÃo revelando o potencial deste fungo na reduÃÃo quimio e regiosseletivas de grupos carbonilas nÃo conjugados Realizou-se o estudo cinÃtico dos produtos de biorreduÃÃo por CLAE e ensaios citotoxicidade frente Ãs linhagens tumorais humanas OVCAR-8 (ovÃrio) SF-295 (glioblastoma) e HCT-8 (cÃlon) O produto biorreduzido 6-gingerdiol apresentou os melhores percentuais de inibiÃÃo do crescimento celular: 91,83; 70,90 e 78,56 respectivamente In this work the biocatalytic potential of the fungus Rhizopus stolonifer a phytopathogenic fungus in biotransformations of natural secondary metabolites was investigated Two of these metabolites the diterpene 3,12-dioxo-15,16-epoxy-4-hydroxycleroda-13(16),14-diene and the phenolic derivative 6-gingerol was biotransformed and their products was isolated and quantified by HPLC The structural determination of biotransformation products was obtained by analysis of 1H NMR 13C NMR 13C-NMR DEPT 135 IV and MS spectrum The products were obtained by a biorreduction process revealing the potential of this fungus in selective reduction of unconjugated carbonyl groups The products from bioreduction were submitted to antitumor assay against human tumor cell lines OVCAR-8 (ovarian) SF-295 (glioblastoma) and HCT-8 (colon) The biotransformation product 6-gingerdiol showed the highest percentage of inhibition of cell growth: 91,83; 70,90 e 78,56, respectively

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Sato, Vanessa Sayuri [UNESP]. "Produção de fitase por Rhizopus microsporus var. microsporus: purificação, caracterização bioquímica e aplicação." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/124519.

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Made available in DSpace on 2015-07-13T12:10:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-27. Added 1 bitstream(s) on 2015-07-13T12:24:13Z : No. of bitstreams: 1 000827083.pdf: 2845300 bytes, checksum: a10a6bf4878453b759ee7bad0b028e37 (MD5) A investigação biotecnológica acompanhada da aplicação das enzimas, combinada com o uso da engenharia genética tem sido realizada em micro-organismos para a produção de enzimas para fins industriais. Entre estas enzimas, as fitases microbianas, que catalisam a hidrólise do fitato (mio-inositol hexaquisfosfato) a mio-inositol e fosfato inorgânico, têm sido amplamente utilizadas na alimentação animal. Neste contexto, o fungo R. microsporus var. microsporus foi selecionado como bom produtor de fitases, com maiores níveis de produção encontrados na Fermentação por Biofilmes (FB) (261,30 U/mg), utilizando bagaço de cana de açúcar como fonte de carbono adicional. A morfologia do biofilme sobre suporte inerte foi analisada por MEV observando-se múltiplas hifas interligadas formando um conjunto ordenado na presença de inúmeros canais que permitem a troca eficiente de nutrientes e oxigenação. A fitase extracelular obtida foi purificada 4,18 vezes com recuperação de 4,78%, obtendo-se uma única banda de 34 kDa em SDS PAGE 12%. A temperatura ótima de atividade para a enzima purificada foi de 55ºC e o pH ótimo 4,5, sendo estável entre 30 °C e 40 °C por 120 min. Apresentou baixa estabilidade ao pH com atividade residual acima de 50% entre pH 3,0 e 5,0 por 60 min. A fitase foi ativada por íons Ca2+ e inibida por K+. A enzima foi capaz de hidrolisar fitato de sódio (Km de 0,72 mM e Vmax de 94,55 U/mg). O extrato bruto contendo fitase foi seco em Spray Dryer com diferentes adjuvantes (farelo de milho, farelo de soja, fubá, amido e maltodextrina). O farelo de soja possibilitou a maior recuperação da atividade fitásica (60%), assim como o fubá (59,5%). Considerando o uso destes dois adjuvantes, o pH ótimo de atividade para a fitase contida no extrato seco foi 4,5 e 8,5, respectivamente e a temperatura ótima de atividade de 45-50 °C. Quando utilizado fubá, a estabilidade foi mantida... Biotechnological research, and the application of enzymes in combination with the use of genetic engineering has been carried out in microorganisms for the production of enzymes for industrial purposes. Among these enzymes, microbial phytases, which catalyze the hydrolysis of phytate (myo-inositol hexakisphosphate) to myo-inositol and inorganic phosphate, have been widely used in animal feed. In this context, the fungus R. microsporus var. microsporus was selected as a good producer of the phytase with higher production levels when grown on Biofilm Fermentation (FB) (261,30 U/mg), using sugarcane bagasse as carbon additional source. The morphology of biofilms on inert support was examined by SEM observing interconnected hyphae forming an ordered array in the presence of many channels which enables efficient exchange of nutrients and oxygen. The extracellular phytase was purified 4.18 fold with 4.78% recovery. A single protein band was obtained in 6% PAGE and confirmed by 12% SDS-PAGE as a single protein band with 34 kDa. The optimum temperature for activity was 55 °C and the optimum pH 4.5. It was completely stable at temperatures between 30 °C and 40 °C for 120 min had low pH with a residual activity of over 50% between pH 3.0 and 5.0 for 60 min. The enzyme was activated by Ca2+ and inhibited by Zn2+. The enzyme was able to hydrolyze sodium phytate with a Km=0.72 mM, Vmax= 94.55 U/mg of protein. The crude extract containing phytase was dried using Spray Dryer with different adjuvants. Soybean meal and corn meal allowed the best recovery of phytase activity 60% and 59.5%, respectively. Considering the use of these two adjuvants, the optimum pH of activity for phytase in the dry extract was 4.5 and 8.5, respectively, and the optimum of temperature of 45-50 °C. When used corn meal, the stability was maintained above 90% at pH 2.5-10.0 for 60 min. The dry phytase (corn meal) was applied to the feed...

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Sato, Vanessa Sayuri. "Produção de fitase por Rhizopus microsporus var. microsporus : purificação, caracterização bioquímica e aplicação /." Araraquara, 2015. http://hdl.handle.net/11449/124519.

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Orientador: Luis Henrique Souza Guimarães Banca: Daniela Alonso Bocchini Martins Banca: José Roberto Ernandes Banca: João Cláudio Thoméo Banca: Patricia Gomes Cardoso Resumo: A investigação biotecnológica acompanhada da aplicação das enzimas, combinada com o uso da engenharia genética tem sido realizada em micro-organismos para a produção de enzimas para fins industriais. Entre estas enzimas, as fitases microbianas, que catalisam a hidrólise do fitato (mio-inositol hexaquisfosfato) a mio-inositol e fosfato inorgânico, têm sido amplamente utilizadas na alimentação animal. Neste contexto, o fungo R. microsporus var. microsporus foi selecionado como bom produtor de fitases, com maiores níveis de produção encontrados na Fermentação por Biofilmes (FB) (261,30 U/mg), utilizando bagaço de cana de açúcar como fonte de carbono adicional. A morfologia do biofilme sobre suporte inerte foi analisada por MEV observando-se múltiplas hifas interligadas formando um conjunto ordenado na presença de inúmeros canais que permitem a troca eficiente de nutrientes e oxigenação. A fitase extracelular obtida foi purificada 4,18 vezes com recuperação de 4,78%, obtendo-se uma única banda de 34 kDa em SDS PAGE 12%. A temperatura ótima de atividade para a enzima purificada foi de 55ºC e o pH ótimo 4,5, sendo estável entre 30 °C e 40 °C por 120 min. Apresentou baixa estabilidade ao pH com atividade residual acima de 50% entre pH 3,0 e 5,0 por 60 min. A fitase foi ativada por íons Ca2+ e inibida por K+. A enzima foi capaz de hidrolisar fitato de sódio (Km de 0,72 mM e Vmax de 94,55 U/mg). O extrato bruto contendo fitase foi seco em Spray Dryer com diferentes adjuvantes (farelo de milho, farelo de soja, fubá, amido e maltodextrina). O farelo de soja possibilitou a maior recuperação da atividade fitásica (60%), assim como o fubá (59,5%). Considerando o uso destes dois adjuvantes, o pH ótimo de atividade para a fitase contida no extrato seco foi 4,5 e 8,5, respectivamente e a temperatura ótima de atividade de 45-50 °C. Quando utilizado fubá, a estabilidade foi mantida... Abstract: Biotechnological research, and the application of enzymes in combination with the use of genetic engineering has been carried out in microorganisms for the production of enzymes for industrial purposes. Among these enzymes, microbial phytases, which catalyze the hydrolysis of phytate (myo-inositol hexakisphosphate) to myo-inositol and inorganic phosphate, have been widely used in animal feed. In this context, the fungus R. microsporus var. microsporus was selected as a good producer of the phytase with higher production levels when grown on Biofilm Fermentation (FB) (261,30 U/mg), using sugarcane bagasse as carbon additional source. The morphology of biofilms on inert support was examined by SEM observing interconnected hyphae forming an ordered array in the presence of many channels which enables efficient exchange of nutrients and oxygen. The extracellular phytase was purified 4.18 fold with 4.78% recovery. A single protein band was obtained in 6% PAGE and confirmed by 12% SDS-PAGE as a single protein band with 34 kDa. The optimum temperature for activity was 55 °C and the optimum pH 4.5. It was completely stable at temperatures between 30 °C and 40 °C for 120 min had low pH with a residual activity of over 50% between pH 3.0 and 5.0 for 60 min. The enzyme was activated by Ca2+ and inhibited by Zn2+. The enzyme was able to hydrolyze sodium phytate with a Km=0.72 mM, Vmax= 94.55 U/mg of protein. The crude extract containing phytase was dried using Spray Dryer with different adjuvants. Soybean meal and corn meal allowed the best recovery of phytase activity 60% and 59.5%, respectively. Considering the use of these two adjuvants, the optimum pH of activity for phytase in the dry extract was 4.5 and 8.5, respectively, and the optimum of temperature of 45-50 °C. When used corn meal, the stability was maintained above 90% at pH 2.5-10.0 for 60 min. The dry phytase (corn meal) was applied to the feed... Doutor

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46

Lima, Jaceline Maria de Negreiros. "Produção do complexo quitosana-polifosfato em Rhizopus oryzae UCP 1506 utilizando substratos agroindustriais." Universidade Católica de Pernambuco, 2013. http://www.unicap.br/tede//tde_busca/arquivo.php?codArquivo=864.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior A quitosana é um polissacarídeo natural originado da deacetilação da quitina. É solúvel em ácido devido à presença de grupos amino, livres ao longo da cadeia do polímero. Os fungos de classe Zygomycetes, em especial Rhizopus oryzae, apresenta em suas paredes celulares quitina e quitosana, podendo as mesmas estar ligadas através de proteínas e polifosfato ou outros componentes, respectivamente. O polifosfato é um biopolímero de ampla aplicabilidade na biotecnologia ambiental. A manipueira é o resultado do processo da mandioca prensada para produção de farinha e utilizada como fonte de carbono nos processos fermentativos. A milhocina é um subproduto da produção de amido de milho e considerada como fonte de nitrogênio. Investigações foram realizadas com Rhizopus oryzae em fermentação submersa para produção de biomassa e do complexo quitosana-polifosfato, através do cultivo em rejeito agroindustrial, manipueira suplementado com milhocina, utilizando um planejamento fatorial completo 23 sobre agitação de 150rpm por 96h. O ensaio com a maior quantidade de biomassa e quitosana foi selecionado para realizar uma cinética de crescimento para avaliar a produção de biomassa e do complexo quitosanapolifosfato. Neste sentido, foi utilizado frascos de Erlenmyers de 500mL de capacidade, contendo 100mL do meio formulado, sendo inoculados em 1mL da suspensão de 107 esporos por mL, incubados sob agitação orbital de 150rpm. As amostras foram coletadas a cada 12 horas até o período de 120h. Os resultados obtidos demonstraram um aumento máximo de biomassa com 48h de cultivo em pH 7,3, com produção máxima da quitosana por R. oryzae de 116mg/g de biomassa em 36h de cultivo. O polifosfato complexado à quitosana apresentou maior rendimento em 36h correspondendo a 13mg/mg de quitosana. Devido os resultados obtidos na produção de biomassa e o complexo de quitosanapolifosfato por Rhizopus oryzae, tornaram-se economicamente viáveis devido à utilização de rejeitos industriais para obtenção desses polímeros. Chitosan is a natural polysaccharide originated from the deacetylation of chitin. It is soluble in acid because of the presence of amino groups, free along the polymer chain. The fungal class Zygomycetes, in particular Rhizopus oryzae, presents in its cell wall chitin and chitosan, and they may be linked through the polyphosphate or proteins and other components, respectively. The polyphosphate is a biopolymer with wide applicability in environmental biotechnology. Manipueira is the result of the process for production of pressed cassava flour and used as carbon source in fermentation processes. The corn steep liquor is a by-product of corn starch and regarded as nitrogen source. Investigations were carried out with Rhizopus oryzae in submerged fermentation for production of biomass and chitosan-polyphosphate complex, through cultivation in agro waste, cassava supplemented with corn steep liquor, using a full factorial design on 23 agitation at 150 rpm for 96h. The test with the greatest amount of biomass and chitosan was selected to perform a growth kinetics to evaluate the production of biomass and chitosan-polyphosphate complex. In this sense, was used bottles of 500ml capacity Erlenmyers containing 100mL of medium formulated being inoculated in 1-ml suspension of 107 spores per ml, incubated under orbital agitation at 150 rpm. Samples were collected every 12 hours until the period of 120h. The results showed a maximum increase of biomass with 48 hours of cultivation at pH 7.3, with maximum production of chitosan by R. oryzae 116mg / g biomass at 36h of cultivation. The polyphosphate complexed to chitosan had the highest yield in 36 h corresponding to 13mg/mg chitosan. Because the results in the production of biomass and chitosan-polyphosphate complex from Rhizopus oryzae, have become economically viable due to the use of industrial wastes to obtain these polymers.

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47

Thongchul, Nuttha. "Lactic acid production by immobilized Rhizopus oryzae in a rotating fibrous bed bioreactor." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1104333442.

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Thesis (Ph. D.)--Ohio State University, 2005. Title from first page of PDF file. Document formatted into pages; contains xviii, 246 p.; also includes graphics (some col.) Includes bibliographical references (p. 207-222).

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Paiva, José Régis de. "Estudo do potencial biocatalítico do fungo Rhizopus stolonifer na biotransformação de produtos naturais." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/14899.

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PAIVA, J. R. Estudo do potencial biocatalítico do fungo Rhizopus stolonifer na biotransformação de produtos naturais. 2014. 75 f. Dissertação (Mestrado em Química) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2014. Submitted by Daniel Eduardo Alencar da Silva (dealencar.silva@gmail.com) on 2014-11-17T19:43:15Z No. of bitstreams: 1 2014_dis_jrpaiva.pdf: 3168577 bytes, checksum: 2dccc004cc1f31dfdf97995945f8f1db (MD5) Approved for entry into archive by José Jairo Viana de Sousa(jairo@ufc.br) on 2016-01-22T19:59:27Z (GMT) No. of bitstreams: 1 2014_dis_jrpaiva.pdf: 3168577 bytes, checksum: 2dccc004cc1f31dfdf97995945f8f1db (MD5) Made available in DSpace on 2016-01-22T19:59:27Z (GMT). No. of bitstreams: 1 2014_dis_jrpaiva.pdf: 3168577 bytes, checksum: 2dccc004cc1f31dfdf97995945f8f1db (MD5) Previous issue date: 2014 In this work the biocatalytic potential of the fungus Rhizopus stolonifer a phytopathogenic fungus in biotransformations of natural secondary metabolites was investigated Two of these metabolites the diterpene 3,12-dioxo-15,16-epoxy-4-hydroxycleroda-13(16),14-diene and the phenolic derivative 6-gingerol was biotransformed and their products was isolated and quantified by HPLC The structural determination of biotransformation products was obtained by analysis of 1H NMR 13C NMR 13C-NMR DEPT 135 IV and MS spectrum The products were obtained by a biorreduction process revealing the potential of this fungus in selective reduction of unconjugated carbonyl groups The products from bioreduction were submitted to antitumor assay against human tumor cell lines OVCAR-8 (ovarian) SF-295 (glioblastoma) and HCT-8 (colon) The biotransformation product 6-gingerdiol showed the highest percentage of inhibition of cell growth: 91,83; 70,90 e 78,56, respectively Neste trabalho investigou-se o potencial biocatalítico do fungo Rhizopus stolonifer um fungo fitopatogênico em biotransformações de metabólitos secundários naturais Dois desses metabolitos, o diterpeno 3,12-dioxo-15,16-epoxi-4-hidroxicleroda-13(16),14-dieno e o derivado fenólico 6-gingerol foram biotransformados e seus respectivos produtos isolados e quantificados por CLAE A elucidação estrutural dos produtos de biotransformação pelo fungo Rhizopus stolonifer foram realizadas por análise dos espectros de RMN 1H RMN 13C RMN 13C-DEPT 135 IV e EM Identificou-se que os produtos obtidos eram provenientes de uma biorredução revelando o potencial deste fungo na redução quimio e regiosseletivas de grupos carbonilas não conjugados Realizou-se o estudo cinético dos produtos de biorredução por CLAE e ensaios citotoxicidade frente às linhagens tumorais humanas OVCAR-8 (ovário) SF-295 (glioblastoma) e HCT-8 (cólon) O produto biorreduzido 6-gingerdiol apresentou os melhores percentuais de inibição do crescimento celular: 91,83; 70,90 e 78,56 respectivamente

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Cruz, Ivone Lopes. "Desenvolvimento de um inóculo seguro, eficiente e padronizado para a produção de tempeh em pequena escala a partir de diferentes leguminosas." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6799.

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Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia Fermented foods from Eastern countries, based on crop fermentations are among the most desired by consumers for their nutrition value and potential as Functional foods and for their diversity and originality. Yet, these products are usually produced by spontaneous and poorly characterized fermentations under non-controlled conditions, which are not compatible with the high quality standards demanded by Western consumers. Tempeh is a popular Indonesian fermented food, originally based on soybean fermented by Rhizopus oligosporus. The objective of this work was to produce safer and effective Rhizopus oligosporus inocula and design standard procedures for safe and consistent tempeh production and conservation. Additionally new tempeh-like fermented products were also produced. Rhizopus oligosporus growth and inoculum preparation and inoculum concentration added to the crop, were optimized to obtain standard tempeh with the desired organoleptic properties. Adjustments on the production steps described for the traditional tempeh manufacture (soaking and fermentation parameters) were also made. Using the optimized procedures, a standard method for inocula and tempeh production was developed. Tempeh maintained its organoleptic properties when stored under vacuum in thermo sealed polypropylene bags and frozen until consumption. The production of several varieties of tempeh using different crops was accomplished under these conditions.

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Bello, Moussibaou. "Interestérification, transestérification et synthèse d'esters catalysées par lipases en microémulsions." Compiègne, 1988. http://www.theses.fr/1988COMPD114.

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Dissertations / Theses on the topic 'Rhizoids'

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