Dissertations / Theses on the topic 'Streptomyce'
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Meanwell, Richard J. L. "Streptomycin production from chitin using Streptomyces griseus." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/12949.
Full textChen, X. "TAGGING BIOCONTROL STREPTOMYCES TO STUDY LETTUCE COLONIZATION." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/345187.
Full textCOLOMBO, ELENA MARIA. "EXPLORING STREPTOMYCES-FUSARIUM INTERACTION TO HAMPER WHEAT HEAD BLIGHT, CROWN ROT AND DEOXYNIVALENOL PRODUCTION." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/692195.
Full textFusarium head blight (FHB), root rot (FRR) and foot rot (FFR) cause important yield losses in wheat. The harvested product is often contaminated with mycotoxins, belonging to the group of trichothecenes. The main causal agents are Fusarium graminearum, F. culmorum and F. pseudograminearum. The biocontrol approach is a feasible option in order to reduce disease severity, as well as trichothecene contamination in grains. Streptomyces spp. are Gram-positive bacteria, ubiquitous in soil and endophytes of inner tissues of plant roots. They produce a wide range of secondary metabolites able to limit pathogen development and disease severity in planta, as well as to enhance plant growth. This PhD project aimed to select Streptomyces strains active within the wheat-Fusarium spp. pathosystem. To achieve this, a detailed literature and patents analysis focused on biocontrol of toxigenic Fusarium spp. was carried out (Chapter 1) and new methodological approaches for antagonist screening have been developed (Chapter 2). Furthermore, the biocontrol efficacy of a selected subset of strains obtained from the culture collection maintained at the Plant Pathology laboratory (DeFENS, University of Milan, Italy) was evaluated in different conditions (Chapter 3) and bioactive metabolites were isolated (Chapter 4). The influence of growth media and Fusarium strain diversity on streptomycete antifungal activity was assessed in dual culture assays. All the factors influenced the level of antifungal activity. The media commonly used for in vitro screening reduced the inhibitory activity of streptomycetes. Overall, results from dual culture assays and level of disease protection observed in planta did not correlate, except for those recorded on a medium based on wheat grains. Indeed, it was the most effective in eliciting antifungal activity and showed the highest correlation (r = 0.5) with FRR inhibition. Subsequently, being TRI5 the first and essential gene involved in trichothecene biosynthetic pathway in Fusarium spp., a microplate bioassay using a TRI5::GFP transformed F. graminearum strain was developed and validated in order to screen the effect of natural products on GFP fluorescence and consequently on trichothecene production. Surprisingly, culture filtrate from DEF39 strain completely suppressed deoxynivalenol (DON) production without affecting fungal growth. The most promising isolates (N = 21) were further characterized for their potential plant growth promotion ability, as well as for their activity against FRR and FFR in wheat seedlings. None of them was able to increase plant growth. However, DEF09 strain exhibited consistent efficacy to limit FRR-FFR symptom severity (protection level > 40%) in soil and soilless conditions. Therefore, a field trial was performed to test its ability to reduce FHB severity, obtaining up to 60% protection. Based on the activity observed from the previous screenings, four promising streptomycetes (DEF09, DEF20, DEF39, DEF48) were applied on sterilized wheat grains (microsilage) at two timepoints of application, in order to evaluate their ability to suppress fungal growth and DON production. Moreover, the fitness of streptomycetes in microsilage conditions was assessed by qPCR analysis. Streptomycetes were able to efficiently colonize the substrate, which resulted in reducing fungal biomass and DON accumulation only when co-inoculated with the pathogen. A pool of promising biocontrol agents has been selected against fungal development and/or DON production. This research highlighted the complexity of finding an efficient screening procedure due to multiple interactions occurring in wheat-Fusarium spp. pathosystem. Further studies will be needed to confirm the activity of the strains in planta. The identification of the mechanisms of action and the molecules involved in the bioactivity of the strains will possibly allow to develop effective treatments limiting trichothecene accumulation in wheat.
Egan, Sharon. "Analysis of the distribution and diversity of streptomycin biosynthetic and resistance genes in populations of Streptomyces." Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343828.
Full textCoyne, Vernon Errol. "Genetic studies of Streptomyces cattleya and Streptomyces olivaceus." Doctoral thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/17599.
Full textActinophage VCll is able to virulently infect 11 of the 20 Streptomyces strains tested. Examination of VCll infection of Streptomyces cattleya, Streptomyces olivaceus and Streptomyces lividans TC10 indicated the absence of restriction-modification systems which affect VCll infectivity of these Streptomyces strains.
Thamm, Sven. "Genetische und biochemische Untersuchungen von StrR dem "pathway"-spezifischen Transkriptionsaktivator von Genen der Streptomycin-Biosynthese in Streptomyces griseus N2-3-11 /." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=975452363.
Full textGenay, Magali Decaris Bernard Dary Annie. "Impact de la réponse stringente sur la mutabilité de Streptomyces coelicolor et Streptomyces ambofaciens au cours de la différenciation." [S.l.] : [s.n.], 2006. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2006_0123_GENAY.pdf.
Full textMurad, Fatima. "Etude de la résistance aux macrolides chez Streptomyces ambofaciens et Streptomyces lividans." Paris 11, 2003. http://www.theses.fr/2003PA112172.
Full textMacrolide antibiotics inhibit protein synthesis by binding to ribosomes. Streptomyces ambofaciens produces spiramycin and possesses several resistance mechanisms to spiramycine and other macrolides. The srmC determinant was studied in the work reported here. It is comprised of three genes: srmC1, srmC2 and srmC3. SrmC1/srmC2 encode the two sub-units of an ABC (ATP Binding Cassette) transporter. They confer resistance to several macrolides, including spiramycin, and to daunorubicin. The two genes srmC1/srmC2 are co-transcribed and their expression is repressed by SrmC3, a repressor of the TetR family. The srmC genes are not localized in the spiramycin biosynthetic gene cluster and are dispensable in S. Ambofaciens. During the study of the induction of srmCl/C2 expression in S. Lividans, a new mechanism of resistance to macrolides and other antibiotics, inducible by the macrolide rosaramicin was discovered in this strain. Genes sclA and sclB, orthologous to srmC1/C2, encoding an ABC transporter are involved in this resistance. SclA and sclB confer multidrug resistance (resistance to macrolides daunorubicin and ethidium bromide). Their expression is controlled by SclR (a TetR-like repressor). The study of a SclA ̄SclR ̄mutant strain suggested that other resistance determinant(s) might be involved in the rosaramicin-inducible resistance. Among macrolide resistance genes from S. Ambofaciens, some have homologues in S. Lividans, others do not. This suggests that some S. Ambofaciens resistant determinants could be directly linked to spiramycin biosynthesis and important for self-protection against spiramycin. Others, including srmC might protect the strain against other toxic compounds encountered in the environment
Carter, T. P. "Keratinase from Streptomyces fradiae." Thesis, Cranfield University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280938.
Full textCalcutt, Michael John. "Pactamycin resistance in Streptomyces." Thesis, University of Leicester, 1987. http://hdl.handle.net/2381/35191.
Full textBourn, William Richard. "Investigation of Streptomyces promoters." Doctoral thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/9651.
Full text[The work described here had multiple aims: to create a promoter probe that was suitable for the isolation of developmentally regulated Strepcomyces promoters, to isolate such promoters, to develop a computer assisted analysis system whereby potential promoter sequences could be determined and to use this in the analysis of the cloned promoters. Initially the suitability of the Streptomyces antibioticus me1C operon for use as a reporter system in Streptomyces was investigated. It was established that late-expressed promoters could be identified and that it was possible to use the me1C2 gene alone for this purpose. However, it was shown that the use of both me1C1 and me1C2 resulted in a more sensitive reporter system. High copy number promoter probe vectors were constructed and tested. A low copy number promoter probe (which used the Streptomyces penemefaciens pSPN1 origin of replication) was also constructed. The characteristics (copy number, stability and mobility) of the probe were established. The conditions in which sporulation was induced by phosphate limitation were identified. Under such conditions late expressing, phosphate dependent promoters were isolated, using the promoter probes previously developed. The expression of these promoters was tested in Streptomyces coelicolor bldA mutants, and the bldA dependent promoters identified. These were sequenced. Computer assisted analysis of DNA sequence bias was conducted, with the intention of using bias patterns to identify potential regulatory regions. The initial approach of using the sequence bias of protein coding regions (based on the premise that regulatory sites are likely to be under represented in these regions) was unsuccessful. Further analysis in which the positional preference of sequences that were over represented in regulatory regions was conducted. Based on this the known promoters of Streptomyces were partially classified. The sequence bias of protein coding DNA regions was used to develop a novel method to identify the protein coding regions of Streptomyces DNA. The computer programs were then used to identify protein coding and potential regulatory regions.
O'Connor, Tamara J. Nodwell J. R. "Establishing cell fate in the multicellular bacterium Streptomyces coelicolor." *McMaster only, 2005.
Find full textNERYS, Laís Ludmila de Albuquerque. "Avaliação das atividades antimicrobiana e anticâncer de metabólitos produzidos por Streptomyces sp UFPEDA 3407." Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/18542.
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Actinobactérias são bactérias Gram-positivas que se destacam pela sua grande potencialidade de produzir diversos metabólitos secundários bioativos de interesse científico e industrial. Mais de 50% dos metabólitos microbianos bioativos descobertos são produzidos, tais como antimicrobianos e antitumorais, pelas actinobactérias principalmente pelo gênero Streptomyces.O câncer é considerado um importante problema de saúde pública em países desenvolvidos e em desenvolvimento, sendo a segunda causa de morte no Brasil e no mundo. Diante da diversidade de tecnologias e pesquisas aplicadas no campo das neoplasias, ainda não há uma terapia eficaz para o tratamento de todos os tipos de câncer e os quimioterápicos utilizados atualmente apresentam elevada toxicidade. Neste contexto, o presente projeto objetivou avaliar o potencial antimicrobiano e anticâncer dos extratos brutos produzidos pela por Streptomyces UFPEDA 3407. Após fermentação e extração dos metabólitos com diferentes solventes, foram realizados ensaios para avaliar a atividade antimicrobiana e citotóxica nas diferentes linhagens de células cancerígenas humanas (HL- 60, HT-29 e MCF- 7) e em eritrócitos murinos. Os resultados obtidos demonstraram que os extratos da biomassa extraídos com acetona, etanol e metanol apresentaram um bom espectro de ação contra bactérias Gram-positivas e leveduras. Nos ensaios de citotoxicidade, os mesmos extratos reduziram de maneira significativa a viabilidade das linhagens tumorais, mostrando resultados bastante promissores.
Actinomycetes are Gram-positive bacteria with high potential to produce various bioactive secondary metabolites of scientific and industrial interest. More than 50% of bioactive microbial metabolites discovered to date are produced by actinomycetes mainly by gender Streptomyces. Cancer is considered a major public health problem in developed and developing countries, and the second cause of death in Brazil and in the world. Given the diversity of technologies and applied research in the field of cancer, there is still no effective therapy for the treatment of all types of cancer and the chemotherapy drugs used today have high toxicity. In this context, this project aimed to evaluate the antimicrobial potential anticancer and crude extracts produced by Streptomyces actinobacteria UFPEDA 3407. After fermentation and extraction of metabolites with different solvents, tests were conducted to evaluate the antimicrobial and cytotoxic activity in different strains of human cancer cells (HL- 60, HT-29 and MCF-7) and murine erythrocytes. Partial results showed that the extracts of biomass extracted with acetone, ethanol and methanol had a good spectrum of action against Gram-positive bacteria and yeasts. In the cytotoxicity assays, the same extracts significantly reduced the viability of tumor cell lines, showing promising results.
Hooten, Jody J. (Jody Jeran). "Identification and Characterization of the Pyrimidine Biosynthetic Operon in Streptomyces griseus." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc277975/.
Full textCong, Lina. "Identification of the midecamycin biosynthetic gene cluster in Streptomyces mycarofaciens UC189B (ATCC 21454) and analysis of the enzymes for dTDP-D-mycaminose biosynthesis." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959140468.
Full textSchindl, Kathrin geb Schmidt [Verfasser]. "Characterisation of Interspecies Interactions between Streptomyces violaceoruber and Streptomyces aburaviensis / Kathrin, geb. Schmidt Schindl." Konstanz : KOPS Universität Konstanz, 2017. http://d-nb.info/1218971711/34.
Full textMoss, Steven J. "Fluorometabolite biosynthesis in Streptomyces cattleya." Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4603/.
Full textHussain, Haitham Ali. "Plasmid transformation in streptomyces niveus." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306525.
Full textCooper, Howard N. "Tetronasin biosynthesis in Streptomyces longisporoflavus." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240902.
Full textKeenan, Tessa. "Protein O-glycosylation in Streptomyces." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/16889/.
Full textHughes, Lee E. (Lee Everette). "Pyrimidine Metabolism in Streptomyces griseus." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc278710/.
Full textMacedo, Juliana Alves 1982. "Produção, purificação, caracterização e aplicação de transglutaminase de Streptomyces sp. CBMAI 837." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254362.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A transglutaminase (TGase) (EC 2.3.2.13; proteina-glutamina ?-glutaminiltransferase) é uma enzima capaz de catalisar reações de transferência de grupos acil utilizando resíduos de glutamina das ligações peptídicas de proteínas como doadores de grupos acil, e diversas aminas primárias como receptores. As ligações covalentes cruzadas entre inúmeras proteínas e peptídeos pela transglutaminase promovem mudanças nas propriedades de proteínas de alimentos. Por essa razão, a transglutaminase é amplamente utilizada nas indústrias de processamento de alimentos para o desenvolvimento de novos produtos e modificação de características como: viscosidade, capacidade emulsificante e valores nutricionais. Uma cepa de Actinomyceto, isolada de amostras de solo brasileiro, foi investigada taxonomicamente por uma combinação de técnicas moleculares e morfológicas, resultando na conclusão de que a cepa pertence ao gênero Streptomyces sp. A cepa, chamada de Streptomyces sp. CBMAI 837 produziu transglutaminase quando cultivada a 30°C por cinco dias, em agitador rotatório, no meio de fermentação otimizado, composto por: 0,2% KH2PO4, 0,1% MgSO4.7H2O, 2% farinha de soja, 2% amido de batata, 0,2% glicose, e 2% peptona, atingindo uma atividade enzimática de 1,37 U.mL-1. A transglutaminase foi purificada cerca de 5 vezes através de duas passagens cromatográficas sucessivas em uma coluna de filtração em gel Sephadex G-75, com 17% de recuperação. A purificação da proteína foi comprovada por homogeneidade eletroforética em SDS-PAGE. A massa molar da TGase foi estimada em cerca de 45 kDa. A transglutaminase de Streptomyces sp CBMAI 837, tanto na forma bruta quanto purificada, apresentou atividade enzimática ótima em pH 6,0-6,5, e em 35-40°C. Um segundo pico de atividade ótima foi observado em pH 10,0 na enzima no estado bruto. Ambas as formas da enzima foram estáveis na faixa de pH de 4,5 a 8,0 e até 45°C. A transglutaminase na forma bruta e purificada mostrou-se independente de íons cálcio, mas foi ativada na presença de K+, Ba2+, e Co2+; e inibida por Cu2+ e Hg2; o que sugere a presença de um grupo tiol no sítio ativo da enzima. A TGase purificada apresentou um Km de 6,37 mM e um Vmax de 1,70 U/mL, enquanto a enzima bruta apresentou Km de 6,52 mM e um Vmax de 1,35 U/mL para o substrato N-carbobenzoxi-L-glutaminil-glicina. A influência da transglutaminase de Streptomyces sp CBMAI 837 bruta, nas propriedades de géis ácidos de caseinato de sódio foi investigada, tendo como parâmetro géis preparados com a TGase comercial (Ajinomoto Inc.). Os géis com a enzima comercial tiveram um valor de módulo de elasticidade maior, porém, dependendo da concentração de proteína, estes foram menos deformáveis. Os géis com enzima bruta de Streptomyces sp. CBMAI 837 se mostraram muito mais rígidos e menos elásticos. Resultados da eletroforese indicaram que a enzima comercial promoveu a formação de polímeros de proteínas de massa molecular mais alta do que a enzima de Streptomyces sp. CBMAI 837. Os testes de microscopia eletrônica de varredura e da capacidade de retenção de água mostraram que características particulares de cada um dos géis poderiam estar associadas ao tipo específico de interação promovida por cada uma das amostras enzimáticas testadas
Abstract: Transglutaminase (EC 2.3.2.13; protein-glutamine ?-glutaminyltransferase) is an enzyme that catalysis an acyl transfer reaction using protein or peptide-bond glutamine residues as acyl donors and several primary amines as receptors. The covalent cross-links between a number of proteins and peptides introduced by transglutaminase promote modification of the functional properties of the food proteins. Therefore, transglutaminase are widely used by food-processing industries for the purpose of new product development, modification of the product properties such as viscosity, emulsification foaming and nutritional values. An actinomycete strain, isolated from Brazilian soil, was taxonomically investigated using a combination of molecular and morphological basedmethods, resulting on the conclusion that the strain belongs to the genus Streptomyces sp. The strain, named Streptomyces sp. CBMAI 837, produce transglutaminase when cultivated at 30°C for 5 days at 200 rpm in a rotatory shaker, on the optimized fermentation medium composed of 0.2% KH2PO4, 0.1% MgSO4.7H2O, 2% soybean flour, 2% potato starch, 0.2% glucose, and 2% peptone, with a enzymatic activity of 1.37 U.mL-1. The enzyme purification was performed by of two successive chromatographies on Sephadex G-75 columns with yields of 48% and 17%, respectively. The protein purification was successfully achieved to electrophoretical homogeneity on SDS-PAGE. The molecular mass of the MTGase was estimated to be about 45 kDa. The enzyme from Streptomyces sp., in both crude and pure forms, exhibited optimal activity in the 6.0-6.5 pH range and at 35-40°C. A second maximum of activity was observed at pH 10.0 on the crude Streptomyces sp. enzyme. Both forms of transglutaminase were stable over the pH range from 4.5 to 8.0 and up to 45°C. The activities of all the TGase samples were independent of Ca+2 concentration, but they were elevated in the presence of K+, Ba2+, and Co2+ and inhibited by Cu2+ and Hg2+, which suggests the presence of a thiol group in the TGase¿s active site. The purified enzyme presented Km of 6.37 mM and Vmax of 1.7 U/mL, while the crude enzyme demonstrated Km of 6.52 mM and Vmax of 1.35 U/mL. The influence of the transglutaminase on acid-gel properties was studied. Texture parameters showed that the commercial TGase (Ajinomoto Inc.) gels had greater values of elasticity modulus and could promote the formation of more elastic and soft food systems, while addition of the crude TGase of Streptomyces sp. CBMAI 837 to the gel led to the formation of more rigid and less elastic gels. The electrophoresis showed that the commercial TG enzyme in this system promoted higher molecular mass protein polymers than the enzyme from Streptomyces sp. CBMAI 837. Microscopy and water holding capacity (WHC) observations showed that all the gel characteristics could be associated to specific interactions promoted by each TGase tested
Doutorado
Doutor em Ciência de Alimentos
Hudson, Michael E. J. Nodwell J. R. "The central role of RamC in Streptomyces coelicolor development /." *McMaster only, 2004.
Find full textRebois, Rolando. "Étude de la production de biomolécules par AFM-IR." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS517.
Full textStreptomyces is a genus of Gram+ filamentous soil bacteria well known for their ability to produce antibiotics and other molecules useful as therapeutic or phytosanitary agents in medicine or agriculture. Under specific growth conditions some strains can store an excess of carbon into TriAcylGlycerols (TAGs), a direct Bio-diesel precursor. Streptomyces is thus an interesting canditate to generate bio-oils by fermentation. In this study, our goal is to evaluate, at the subcellular scale, the size/shape and localization of storage lipid inclusions in different Streptomyces strains (such as Streptomyces lividans (TK24), Streptomyces coelicolor (M145)…).In a previous study, the global TAGs content of those strains was easily and precisely quantified using infrared (IR) spectroscopy and thin layer chromatography revealing among other things that S. coelicolor has a very low TAGs content whereas S. lividans has an high TAG content. This was possible since TAG molecules show a specific response in the mid-infrared (IR) region, quite distinct from that of the other cellular constituants.Triacylglycerols posses several absorption bands in IR. In particular we can easily distinguish the band of the C=O stretching of the esters at 1741 cm-1 from the amide I band (protein signature) of the bacterium.For the study of the local repartition of TAG inside the cells, a combination of atomic force microscopy and infrared spectroscopy was employed in order to create sub-cellular chemical maps that allow label-free identification of TAG inclusions in Streptomyces cytoplasm using their specific absorption properties at 1741 cm-1. AFM-IR is a user-friendly benchtop technique that enables infrared spectroscopy with a spatial resolution well below conventional optical diffraction limits. It acquires IR absorption imaging with lateral resolution down to 100 nm.This technique coupled with classical FTIR measurements constitutes a powerful tool to study TAG metabolism in Streptomyces and can be easily used to control the rate of lipid accumulation during the fermentation process. Hence, the AFM-IR technique is likely to provide new insights into the constitution of the fatty inclusions and the role of TAGs in the morphological and metabolic differentiation processes that characterize Streptomyces developmental cell cycle
Soror, Sameh. "Characterisation of esterase genes in the genomes of Streptomyces coelicolor A3(2) and Streptomyces avermitilis." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=983770069.
Full textCattini, Nicola. "Phosphate regulation in Streptomyces coelicolor and Streptomyces lividans : transcriptomic analysis of phoP and Ppk mutants." Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/843545/.
Full textMersinias, Vassilios. "DNA microarray-based analysis of gene expression in Streptomyces coelicolor A3(2) and Streptomyces lividans." Thesis, University of Manchester, 2004. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488026.
Full textNezbedová, Šárka. "Métabolisme secondaire chez Streptomyces ambofaciens et Streptomyces lividans et sa régulation : nouvelles voies de biosynthèse." Paris 11, 2010. http://www.theses.fr/2010PA112369.
Full textThe presented work is focused on secondary metabolism and its regulation in Streptomyces ambofaciens and Streptomyces lividans with special interest in new biosynthetic pathways. The sequencing of bacterial and fungal genomes revealed that the number of their secondary metabolite biosynthetic gene clusters greatly exceeds the number of produced secondary metabolites. Further studies showed that at least some of the newly discovered clusters, called cryptic since no product had been associated to them, were expressed in certain conditions and that they directed the biosynthesis of exploitable secondary metabolites. Therefore, these cryptic clusters have been considered as one of the promising reservoirs of new bioactive molecules. Using different approaches I studied the cryptic secondary metabolite biosynthetic gene clusters of Streptomyces ambofaciens, a strain exploited industrially for the production of the antibiotic spiramycin. In the second part of this work, I was interested in the regulation of secondary metabolite biosynthesis and in manipulating regulatory proteins in order to activate the expression of cryptic clusters. The third part of this work studied the effect of the inactivation of the ppk gene, encoding the enzyme polyphosphate kinase, on the production of secondary metabolites and on the whole protein expression pattern in Streptomyces lividans
Bagagli, Marcela Pavan 1981. "Produção de transglutaminase de Streptomyces sp. P20 = caracterização da enzima bruta." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254327.
Full textDissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Engenharia de Alimentos
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Resumo: A transglutaminase (TGase, EC 2.3.2.13) é uma enzima que catalisa a formação de ligações cruzadas entre resíduos de glutamina e aminas livres de proteínas formando agregados protéicos. Foi estudado o aumento da escala de produção da transglutaminase de Streptomyces sp. P20, de frascos Erlenmeyer agitados de 50 mL contendo 15 mL de meio de cultivo para fermentador de bancada de 6 L com volume útil de 3 L. Para a fermentação em frascos agitados foi utilizado o meio de cultivo otimizado por MACEDO et al. (2007) e para a fermentação do microrganismo em reator de bancada foi utilizado esse útimo meio de cultivo modificado, composto de extrato de 2,5% de farinha de soja, 2% de amido de batata, 1% de peptona, 0,1% de glicose, 04% de KH2PO4 e 0,2% de MgSO4, ajustado para pH 7,0. Foi estudado, através de delineamento fatorial, os efeitos da temperatura, agitação e aeração na fermentação da linhagem de Streptomyces sp. P20 no reator de bancada e a produção de transglutaminase. O aumento da escala de 200 vezes proporcionou uma elevação na atividade enzimática de 7,2 vezes, e o tempo para obtenção desta atividade foi reduzido de 120 horas para 42 horas de fermentação, utilizando dois estágios de temperatura. A atividade máxima obtida em reator de bancada foi de 2,05 U/mL de caldo fermentado. No estudo da produção da transglutaminase de Streptomyces sp. P20, por fermentação em meio semi-sólido, utilizando-se como substratos farinha de feijão branco e farinha de amendoim, foram obtidos, respectivamente, atividade de transglutaminase iguais a 0,88 U/g de substrato seco e 0,77 U/g de substrato seco. A caracterização bioquica da transglutaminase bruta de Streptomyces sp. P20 foi estudada, bem como a aplicação da enzima em carne bovina e proteína texturizada de soja. Os valores de temperatura ótima e pH ótimo desta enzima foram avaliados, sendo verificado que a temperatura ótima de atividade foi de 35°C e o pH 6,5, sendo encontrada uma segunda faixa de pH ótimo em 9,0, o que pode indicar a presença de isoenzimas. A MTGase mostrou-se estável na faixa de pH 6,0 ¿ 9,0, e at·a temperatura de 35°C em pH 6,0 por 30 minutos. O aminoácido L-cisteína aumentou a estabilidade térmica da MTGase de Streptomyces sp. P20. O efeito de íons metálicos, do EDTA, L-cisteína, L-glutationa e PEG 6000 na atividade da MTGase foram avaliados. Os íons Hg2+, Cu2+, Zn2+ e Mn2+, inativaram a enzima, sugerindo a presença de grupos tiol no seu sítio ativo. O íon Mg2+ aumentou a atividade da MTGase cerca de 100%. A aplicação da MTGase de Streptomyces sp. P20 em carne bovina e em prote?a texturizada de soja foi eficiente quando comparada a aplicação da enzima comercial Activa TG-BP aplicada nas mesmas condições
Abstract: Transglutaminase (TGase, EC 2.3.3.13) is an enzyme that catalyzes cross-linking between the glutamine and free amine residues of proteins leading to the formation of protein aggregates. The scale up of the production of transglutaminase by Streptomyces sp. P20 from shaken flasks to a bench fermenter was studied. Initially, the effect of temperature and agitation on the microorganism was studied in 50 mL conical flasks containing 15 mL of culture medium previously optimized by MACEDO et al. (2007). The production in 250 mL conical flasks containing 50 mL of the same culture medium was then studied. For fermentation in the bench reactor the same medium was used, modified, containing extract of 2.5% powdered soy, 2% potato starch, 1% peptone, 0.1% glucose, 0.4% KH2PO4 and 0.2% MgSO4, pH 7.0. A factorial design was used to study the effects of temperature, agitation and aeration on the fermentation of the strain Streptomyces sp. P20 in a 6L bench fermenter. The x200 scale up led to a x7.2 enhancement in enzymatic activity, and the fermentation time decreased from 120 h to 42 h using two temperature (from 34°C during the first 24 hours to 26°C for the remaining time) and agitation (from 350 rpm during the first 24 hours to 150 rpm for the remaining time) shifts. The maximum transglutaminase activity obtained was 2.05 U/mL. In the solid state fermentation study using semi-solid media containing white bean flour and peanut flour, transglutaminase activities of 0.88 U/mg dried substrate and 0.77 U/mg dried substrate, respectively, were obtained. The biochemical characterization of the crude transglutaminase obtained from Streptomyces sp. P20 and its application in beef and texturized soy protein were studied. The optimum temperature and pH values for MTGase activity were investigated, exhibiting optimum activity at 35°C and at both pH 6.5 and pH 9.0, probably due to the presence of an isoenzyme. The enzyme was stable in the pH range from 6.0 ¿ 9.0, and at temperatures of up to 35?C it was stable for 30 minutes at pH 6.0. The amino acid Lcysteine enhanced the thermal stability of the MTGase from Streptomyces sp. P20. The effects of metal ions, EDTA, L-cysteine, L-glutathione and PEG 6000 on the activity of MTGase were investigated. The ions Hg2+, Cu2+, Zn2+ and Mn2+ inhibited enzyme activity, suggesting the presence of a thiol group at the active site of the enzyme. The ion Mg2+ increased MTGase activity by 100%. The application of MTGase from Streptomyces sp. P20 in beef and texturized soy protein was efficient when compared to the application of commercial Activa TG-BP under the same conditions
Mestrado
Mestre em Ciência de Alimentos
Sairre, Mirela Inês de. "Estudos sobre a síntese de butirolactonas auto-reguladoras de bactérias Streptomyces." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-14052007-083437/.
Full textStreptomycetes are Gram-positive filamentous bacteria well known for the ability to produce a wide variety of secondary metabolites and biologically active substances. These activities are controlled by low-molecular-weight compounds called butyrolactone autoregulators. The greater number of these compounds with autoregulators properties have as common characteristic a 2,3-disubstituted-g-butyrolactone sketeton, but show minor structural differences in the side chain. These molecules, whose structures are shown below, are classified following the types: virginiae butanolides (VB) A-E, Gräfe\'s factors, IM-2 butanolide, I-factor and A-factor. In this work, studies were developed with aim to test a new synthetic pathway to obtain A-factor analogous, which by enantioselective reduction of the carbonyl group of the side chain can be converted into others butyrolactone autoregulators. First of all, the necessary intermediary for the synthesis of the desired compounds was prepared by a transesterification reaction, which was widely studied. After that, an intramolecular cyclization reaction of this intermediary could to produce the A-factor analogous. However, after several attempts employing different reactional conditions, the desired compounds were not obtained. Theoretical calculation was realized as an attempt to explain the experimental results obtained and should possible to conclude this study adequately. Two other two synthetic approaches for the preparation A-factor analogous were developed and tested, but the results were not good enough. Thus, a new study based on a method of intermolecular synthesis of butyrolactones was developed. This new synthetic strategy would allow to obtain the A-factor in only 3 steps: a reaction of oxirane ring opening, followed by an ozonolysis reaction and a selective reduction of an aldehyde group. The different groups present in the epoxides tested showed different effects, which were better understood with the aid of theoretical calculation. The attainment of the desired butyrolactone with 52% yield, a product containing a terminal olefin, confirm the success of this new synthetic strategy. However, up to this moment, the ozonolysis reaction was not giving good results. The difficulty for this step is probably associated with the volatileness, the high solubility in water and/or the degradation of the aldehyde formed, making difficult its isolation. However, as this type of reaction is already reported in the literature employing the reagents K2OsO4, N-methylmorpholine N-oxide (NMO) and NaIO4 to cleave the terminal double, we have the conviction that our aim could be accomplished with modifications on the reactional conditions and/or of the reagents which are necessary to realize with success this final step.
Previdi, Daniel. "Estudos sobre a síntese de derivados de cyclophostin inibidores da acetilcolinesterase (AChE)." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-31072014-155044/.
Full textBacteria of the genus Streptomyces produce many kinds of butyrolactones; e.g., cyclophostin, compounds belonging to the cyclipostin family, and -butyrolactones autoregulators. Cyclophostin is a potent inhibitor of the enzyme acetylcholinesterase, the compounds of the cyclipostin family inhibit lipases, and -butyrolactones autoregulators stimulate antibiotics production in bacterial cultures of the genus Streptomyces. This work aimed to obtain cyclophostin derivatives and -butyrolactones autoregulators derivatives via two proposed synthesis designs as illustrated in schemes 8 and 10 (Section: III. Synthetic Planning). The key step in the design shown in scheme 8 consisted of a Barbier reaction between butenolide 43, several aldehydes, and a metal (zinc or indium), in aqueous medium. Although this reaction has long been known, the tests performed here did not afford any of the target compounds. The main product was compound 56, arising from the reduction of butenolide 43. An explanation for the results was proposed on the basis of possible mechanisms for the Barbier reaction and of comparison with similar compounds of butenolide 43, which have been successfully used in the Barbier reaction. Studies carried out according to the synthesis design presented in scheme 10 provided satisfactory results. The reaction between butadiene monoxide and various -ketoesters furnished 2,3-disubstituted--butyrolactones as a single diastereoisomer and 2,4-disubstituted--butyrolactones as a mixture of diastereoisomers (shown in Table 7). NOEDiff-NMR analysis together with literature data and computer calculations of coupling constants helped to determine the relative configuration of the 2,3-disubstituted--butyrolactones substituent groups as trans. Three 2,3-disubstituted--butyrolactones ozonolysis reactions were conducted by reductive cleavage of the ozonide with sodium borohydride, which afforded three compounds as diastereoisomers mixtures bearing structures analogous to those of IM-2 and virginiae butanolides (shown in Table 8). Reaction of -butyrolactone 54a with diethyl chlorophosphate as phosphorylating agent produced the enol-phosphate 55a (reaction shown in Scheme 23). Ozonolysis reactions of this compound using sodium borohydride or dimethyl sulfide to cleave the ozonide did not provide satisfactory results (reaction shown in Scheme 24). Other attempts to achieve cyclophostin derivatives using different starting materials failed during the ozonolysis step or the cyclization to form the cyclic enol-phosphate skeleton present in cyclophostin. Despite the poor results described above, some of the intermediates were submitted to a biological assay to monitor production of the antibiotic nigericin in Streptomyces actinomycetes cultures. Some of the tested compounds stimulated, others inhibited, and others did not affect nigericin production, indicating existence of a structure-activity relationship.
Galey, Laurent. "Géosmine, sesquiterpènes, alkylpyrazines et dérivés aromatiques chez "Streptomyces griseus" : étude génétique et biochimique." Paris 5, 1989. http://www.theses.fr/1989PA05P619.
Full textGenay, Magali. "Impact de la réponse stringente sur la mutabilité de Streptomyces coelicolor et Streptomyces ambofaciens au cours de la différenciation." Nancy 1, 2006. http://docnum.univ-lorraine.fr/public/SCD_T_2006_0123_GENAY.pdf.
Full textIn nature, organisms are constantly subjected to chemical, physical or nutritional variations of the environment. The modulation of the mutation rate constitutes one of the mechanisms contributing to the adaptation of bacterial species to rapid environmental modifications. The aim of this work was to highlight the influence of environmental factors on the genetic instability characterized in Streptomyces species. Through the study of S. Ambofaciens and S. Coelicolor mutants, not pigmented, unable to sporulate and produced during the aerial mycelium growth, we showed that a limitation in amino acids constituted a mutagen condition. Indeed, on amino acid-limited media, the production of these mutants was strongly increased. A mutation in their whiG or whiH genes, two genes intervening in the first stages of the sporulation process, was frequently detected. We could highlight, via the study of the relA mutant of S. Coelicolor, the existence of a link between stringent response, the physiological response induced during an amino acid limitation, and increase in the mutability of these genes. There is thus a relation between a nutritive limitation and an increase in genetic instability via the establishment of a local or global mutator state, initiated by the induction of the stringent response. The produced mutants could contribute to the survival of the colony during an amino acid limitation metabolising substances different from the rest of the colony or allowing the release of nutrients, food for the neighbour cells
Hughes, Lee E. (Lee Everette). "Pyrimidine Biosynthesis in the Genus Streptomyces : Characterization of Aspartate Transcarbamoylase and Its Interaction with Other Pyrimidine Enzymes." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc278797/.
Full textHaug, Iris. "Das Streptomyces coelicolor A3(2) Plasmid SCP2* : Ermittlung der vollständigen Sequenz und daraus abgeleitete Funktionen /." [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10605150.
Full textKYRIAKIDIS, XENOPHON. "Contribution a l'etude du systeme d'excretion des proteines chez streptomyces : clonage d'un gene codant pour une protease extracellulaire d'une souche de streptomyces sp. chez streptomyces violaceoniger." Toulouse 3, 1989. http://www.theses.fr/1989TOU30027.
Full textBauer, Norbert. "Curdlanase, ein extrazelluläres hefelytisches Enzym von Streptomyceten." [S.l.] : [s.n.], 2002. http://edoc.ub.uni-muenchen.de/archive/00000642.
Full textNeusser, Dietmar. "Untersuchungen zur Biosynthese der Propylprolin-Untereinheit des Antibiotikums Lincomycin A aus Streptomyces lincolnensis." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=958333629.
Full textArnold, Antje. "Untersuchungen zur Biosynthese der Methylthiolincosaminid (MTL) Untereinheit des Antibiotikums Lincomycin A aus Streptomyces lincolnensis NRRL 2936." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=95913669X.
Full textHaase, Malte. "Untersuchungen zum Mechanismus der Kondensation zwischen Trans-4-n-Propyl-L-Prolin und [alpha]-Methylthiolincosaminid [Alpha-Methylthiolincosaminid] der Lincomycin-A-Biosynthese aus Streptomyces lincolnensis NRRL 2936." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971614377.
Full textAnttonen, Katri Pauliina. "Protein glycosylation in actinomycetes." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=92515.
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Full textBrunelliere, Jérôme. "Caractérisation des voies métaboliques d'une souche de Streptomyces impliquée dans la production de vanilline." Clermont-Ferrand 2, 2009. http://www.theses.fr/2009CLF21947.
Full textTronquet, Claude. "Production, extraction et caractérisation de la sohbumycine, une nouvelle molécule produite par Streptomyces sp. No 82-85." Montpellier 1, 1990. http://www.theses.fr/1990MON13512.
Full textSurowitz, Kenneth Gene. "Carbon source metabolism and differentiation in Streptomyces alboniger /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487262513409327.
Full textSchlasner, Steven Mark. "On-line, adaptive, optimal control of a high-density, fed-batch fermentation of Streptomyces C5 /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487329662146826.
Full textSmith, Todd M. "Genetic and biochemical studies of thiostrepton biosynthesis in Streptomyces laurentii /." Thesis, Connect to this title online; UW restricted, 1993. http://hdl.handle.net/1773/8187.
Full textBlanchard, Josée. "Étude des 10 hélices-[alpha] de la chitosanase de Streptomyces sp. N174 en vue d'augmenter la thermostabilité et/ou l'activité de cette enzyme." Sherbrooke : Université de Sherbrooke, 2002.
Find full textPlouffe, Bertrand. "Production de chitosanases modulaires munies d'un site d'attachement à la cellulose et étude de leur activité en bioréacteur." Sherbrooke : Université de Sherbrooke, 1998.
Find full textKheder, Fadi Girardin Michel Delaunay Stéphane. "Production et purification d'acide férulique estérases. Application à la synthèse d'esters phénoliques." S. l. : INPL, 2007. http://www.scd.inpl-nancy.fr/theses/2007_KHEDER_F.pdf.
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