Microbiologia

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840

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Data inicial: 2002Data final: 2009Assunto: search.filters.subject.Pectin lyase

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Agora exibindo 1 - 3 de 3
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    Molecular characterization and expression profile of pectin-lyase-encoding genes from Penicillium griseoroseum
    (Canadian Journal of Microbiology, 2006) Bazzolli, Denise S.; Ribon, Andrea O. B.; Queiroz, Marisa V. de; Araujo, Elza F. de
    Penicillium griseoroseum has been studied by our group because of its good pectinase production. Attempts have been done to clone pectinolytic genes, aiming to obtain pectinase-overproducing strains for industrial purposes. Here, two genes coding for pectin lyase were isolated from the P. griseoroseum genome. The plg1 gene has an open reading frame of 1341 bp coding for a putative protein of 374 amino acids with a calculated molecular mass of 40.1 kDa. The plg2 gene is characterized by an open reading frame of 1400 nucleotides and codes for a polypeptide of 383 amino acids. The plg1 gene 5'-flanking region contains putative binding sites for the transcription factors involved in regulation by ambient pH and catabolite repression. The primary structure of Plg1 and Plg2 proteins showed a relatively high homology (varying between 32.4% and 74.8%) to fungal pectin lyases characterized to date. Southern blotting analysis revealed that both genes are present as single copies in the fungus genome. Expression studies revealed a differing pattern of gene expression of plg1 and plg2 when mycelium was cultivated on medium containing different pectic components. Citric pectin followed by apple pectin were the carbon sources that best induced plg1 expression, and transcripts were detected from 24 to 76 h. The expression of the plg2 gene was monitored by reverse transcriptase--polymerase chain reaction, since Northern analysis failed to detect hybridization signals. The differential expression of these genes may provide means for the fungus to adapt to various growth conditions.
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    Molecular characterization and evaluation of pectinase and cellulase production of Penicillium spp.
    (Biotechnology Letters, 2002-05) Pereira, Jorge Fernando; Queiroz, Marisa Vieira de; Gomes, Eliane Aparecida; Muro-Abad, Júpiter Israel; Araújo, Elza Fernandes de
    Penicillium species were analyzed with molecular markers and for pectinase and cellulase production. RAPD and PCR-RFLP analysis indicated high polymorphism among at least 5 of 10 Penicillium species. Five species were chosen for pectinase and cellulase production in liquid medium and four of which appeared similar based on molecular analyses. P. brevicompactum and P. griseoroseum gave the highest pectinase production and were highly divergent by molecular techniques.
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    Differential expression of plg genes from Penicillium griseoroseum: plg1 a pectinolytic gene is expressed in sucrose and yeast extract
    (Journal of Applied Microbiology, 2008-04-22) Bazzolli, D.M.S.; Ribon, A. de O.B.; Reis, K.C.P.; Queiroz, M.V. de; Araújo, E.F. de
    To study the regulation of the plg1 and plg2 genes of Penicillium griseoroseum, in order to identify the industrial potential of their products in alternative carbon sources that are cheaper and widely available in Brazil. RT-PCR and Northern blot were used to investigate if plg1 and plg2 expression is under influence of catabolic repression, ambient pH and cAMP. Results demonstrated that the genes were differentially regulated depending on the carbon sources in the culture medium and pH. Sucrose, a noninducing carbon source of the pectinolytic system, was able to promote plg1 transcription but only when yeast extract was added into the culture medium. The plg genes are differentially expressed. The plg1 gene is more attractive for industrial use due to its expression in alternative carbon sources like sucrose and yeast extract. In recent years, industries have been trying to replace the toxic conventional treatments employed in these processes by more eco-friendly enzyme treatment. Alternative carbon sources will be tested with the aim to reduce the costs associated to pectin lyase production in Brazil.