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You searched for subject:(Polyketide synthase genes). Showing records 1 – 2 of 2 total matches.

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1. Rojas, Juan Diego Rojas. Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar.

Degree: PhD, Biotecnologia, 2010, University of São Paulo

A partir de 280 isolados fúngicos de cana-de-açúcar, 18 cepas foram avaliadas quanto á presença de genes da policetídeo sintase por meio da técnica do PCR. Estes fungos foram identificados taxonomicamente por uma abordagem polifásica, classificando-os dentro de quatro ordens e nove gêneros. A avaliação da atividade biológica demonstrou a presença de metabolitos com propriedades antibióticas quando enfrentados a micro-organismos patogênicos. Segundo a análise de correspondência múltipla, esta atividade poderia estar associada com a local de isolamento dos fungos. Foram detectadas 36 seqüências similares a genes PKS a partir de 17 destes fungos. A análise filogenética do domínio KS, conduzida pelo método de neighbor-joining, indicou que 16 seqüências se acomodaram dentro do grupo monofilético dos PKS envolvidos na produção de policetídeos não reduzidos e as outras 10 seqüências se acomodaram dentro do grupo monofilético dos PKS envolvidos na produção de policetídeos reduzidos. A análise do domínio CMT também apontou que as seqüências podiam se acomodaram em grupos de PKS dependendo do grau de redução do policetídeo, todas as seqüências CMT se relacionaram com PKS envolvidos na produção de policetídeos reduzidos. As análises dos modelos estruturais também demonstraram que as seqüências estavam altamente relacionadas com estruturas protéicas da família das enzimas de condensação, destacando a presença de uma hélice característica que carrega o resíduo de cisteína, responsável pela atividade de condensação. Extratos orgânicos obtidos de cultivos dos fungos foram avaliados parar detectar a presença de compostos tipo lovastatina. Por meio de cromatografia CCDS, detectaram-se bandas de 10 extratos com o mesmo deslocamento que a lovastatina padrão, mas apenas 6 destas foram confirmados por CLAE. O isolado A. flavus CBMAI 1023, foi selecionado para a realização de experimentos de produção a maior escala onde foi possível isolar e caracterizar um novo policetídeo.

From a group of 280 sugarcane-derived fungi 18 strains were assessed for the presence of polyketide synthase genes by PCR approaches. These fungi were identified taxonomically by a polyphasic approach classifying into four orders and nine genres. Biological activity tests showed the presence of antibiotic metabolites against pathogenic microorganisms and the relationship of this activity might be linked with the fungal isolate location by multiple correspondence analyses. 36 sequences similar to PKS genes fragments were detected from 17 of these fungi. A neighbor-joining phylogenetic analysis of the KS domain showed that 16 sequences fit on the monophyletic group of PKS evolved with production of non reduced polyketides, and the other 10 sequences fit on the monophyletic group of PKS evolved with the production of reduced polyketides. CMT domain analysis also pointed that the sequences fit with groups of PKS depending on polyketide reduction grade, all ten related to PKS evolved with the synthesis of reduced polyketides. Protein structural analysis also pointed…

Advisors/Committee Members: Maldonado, Gabriel Padilla, Silva, Luiziana Ferreira da.

Subjects/Keywords: C methyltransferase (CMT); C-metiltransferase (CMT); Cetosintase (KS); Chromatography; Cromatografia; Endophytic fungi; Fungos endofíticos; Genes; Genes; Genética microbiana; Keto synthase (KS); Lovastatin; Lovastatina; Microbial genetics; Policetídeo sintase (PKS); Policetídeos (PK); Polyketide (PK); Polyketide synthase (PKS); Polymerase Chain Reaction (PCR); Reação em Cadeia por Polimerase (PCR)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rojas, J. D. R. (2010). Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/87/87131/tde-22122010-162031/ ;

Chicago Manual of Style (16th Edition):

Rojas, Juan Diego Rojas. “Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar.” 2010. Doctoral Dissertation, University of São Paulo. Accessed January 23, 2021. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-22122010-162031/ ;.

MLA Handbook (7th Edition):

Rojas, Juan Diego Rojas. “Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar.” 2010. Web. 23 Jan 2021.

Vancouver:

Rojas JDR. Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar. [Internet] [Doctoral dissertation]. University of São Paulo; 2010. [cited 2021 Jan 23]. Available from: http://www.teses.usp.br/teses/disponiveis/87/87131/tde-22122010-162031/ ;.

Council of Science Editors:

Rojas JDR. Prospecção de genes biossintéticos de policetídeos a partir de fungos isolados de cana-de-açúcar. [Doctoral Dissertation]. University of São Paulo; 2010. Available from: http://www.teses.usp.br/teses/disponiveis/87/87131/tde-22122010-162031/ ;


INP Toulouse

2. Bacha, Nafees. Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach).

Degree: Docteur es, Microbiologie et biocatalyse industrielles, 2009, INP Toulouse

Aspergillus westerdijkiaem qui est récemment démembré d'A. ochraceus est un producteur principal de plusieurs composés de type polycétone d'importance économique. Ces composés incluent l’ochratoxin A, mellein, l'acide penicillique, asperlactone et l’isoasperlactone et quelques intermédiaires comme l'acide 6- methylsalicylique et l’acide orsellinique. La biosynthèse de ces métabolites est catalysée par un groupe d'enzymes connues comme la polycétone synthases (PKSs). Ce travail a été visé pour cloner et a caractérisé fonctionnellement les différentes genes des PKS i.e. aoks1, aolc35-12 et aomsas, et de genes de polyketide synthases-non ribosomal peptide synthase (PKS-NRPS) i.e. aolc35-6, chez A. westerdijkiae. Ces gènes ont été inactivés par l'insertion du gène d’hygromycine B phosphotransferase d’Escherichia coli dans le génome d'A. westerdijkiae, pour obtenir les mutantes ao?ks1, ao?lc35-12, ao?msas et ao?lc35-6. Les mutants ao?ks1 et ao?lc35-12 ont été trouvés déficients dans la biosynthèse d’ochratoxin A, mais produisaient encore mellein. À notre connaissance, c’est la première fois que nous avons caractérisé les gènes impliquées dans la biosynthèse d’OTA, sachant que mellein, qui était proposé dans la littérature comme un intermédiaire, joue a cune role dans la biosynthesis de l'OTA. Ensuite le mutant ao?msas n'a pas seulement perdu la capacité de produire isoasperlactone et asperlactone, mais aussi il ne produit pas l’intermédiaire acide 6-methylsalicylique. Basé sur les expériences de la caractérisation génétique et de complémentation chimiques, nous avons proposé un shéma hypothétique de la biosynthèse d’asperlactone et isoasperlactone dans lequel l'acide 6-methylsalicylique, diepoxide et aspyrone jouent le rôle d’intermédiaires. La techniques de gène knock-out et de la reverse transcription PCR (RT-PCR) ont montré que seulle gène de type PKS-NRPS « aolc35-6 » identifié chez A. westerdijkiae codant pour un intermédiaire inconnu(s) qui pourrait inciter l'expression de gène aomsas et un gène impliqué dans la biosynthèse d'acide orsellinique et d'acide penicillique.

Aspergillus westerdijkiaem which is recently dismembered from A. ochraceusm is the principal producer of several economically important polyketide metabolites. These metabolites include ochratoxin A, mellein, penicillic acid, asperlactone and isoasperlactone and some intermediates like orsellinic acid and 6-methylsalicylic acid. The biosynthesis of these metabolites is catalyzed by a group of enzymes known as polyketide synthases (PKSs). This work was aimed to clone and functionally characterized various PKS i.e. aoks1, aolc35-12 and aomsas, and polyketide synthasesnon ribosomal peptide synthase (PKS-NRPS) genes i.e. aolc35-6, in A. westerdijkiae. These genes were inactivated by the insertion of Escherichia coli hygromycin B phosphotransferase gene in the genome of A. westerdijkiae to obtain ao?ks1, ao?lc35-12, ao?msas and ao?lc35-6 mutants. ao?ks1, ao?lc35-12 mutants were found deficient in ochratoxin A biosynthesis but are still producing…

Advisors/Committee Members: Lebrihi, Ahmed (thesis director), Mathieu, Florence (thesis director).

Subjects/Keywords: Aspergillus westerdijkiae; Polycétone synthase gènes; Caractérisation génétique; Genome walking; Transformation; Complémentation chimique; Ochratoxine A; Acide penicillique; Aspyrone; Acide 6-methylsalicylique; Isoasperlactone; Asperlactone; Aspergillus westerdijkiae; Polyketide synthase genes; Genetic characterization; Genome calking; Transformation; Chemical complementation; Ochratoxin A; Penicillic acid; Aspyrone; 6-methylsalicylic acid; Isoasperlactone; Asperlactone

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bacha, N. (2009). Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach). (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2009INPT004A

Chicago Manual of Style (16th Edition):

Bacha, Nafees. “Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach).” 2009. Doctoral Dissertation, INP Toulouse. Accessed January 23, 2021. http://www.theses.fr/2009INPT004A.

MLA Handbook (7th Edition):

Bacha, Nafees. “Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach).” 2009. Web. 23 Jan 2021.

Vancouver:

Bacha N. Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach). [Internet] [Doctoral dissertation]. INP Toulouse; 2009. [cited 2021 Jan 23]. Available from: http://www.theses.fr/2009INPT004A.

Council of Science Editors:

Bacha N. Caractérisation des polycétones synthases intervenant dans la biosynthèse d’ochratoxine A, d’acide pénicillique, d’asperlactone et d’isoasperlactone chez aspergillus westerdijkiae : Caracterization of the polyketide synthases involved in biosynthesis of ochratoxin A, penicillic acid, asperlactone and isoasperlactone in aspergillus westerdijkiae (a molecular approach). [Doctoral Dissertation]. INP Toulouse; 2009. Available from: http://www.theses.fr/2009INPT004A

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