Microbiologia

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

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Data inicial: 2010Data final: 2015Assunto: search.filters.subject.Pectin lyase

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Agora exibindo 1 - 3 de 3
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    Pectin lyase production by recombinant Penicillium griseoroseum strain 105
    (Canadian Journal of Microbiology, 2010) Teixeira, Janaina Aparecida; Queiroz, Marisa Vieira de; Araújo, Elza Fernandes de; Cardoso, Patrícia Gomes
    Recombinant Penicillium griseoroseum strain 105 overproduces an extracellular pectin lyase (PL) under the transcriptional control of the strong gpdA promoter of Aspergillus nidulans. Our aim was to evaluate PL production by recombinant P. griseoroseum strain 105 in submerged fermentation system bioreactors BioFloIII and BioFloIV using 2 or 10 L working volumes under different growth conditions and to analyze the production of cellulase, polygalacturonase, pectin methylesterase, and protease. PL overproduction by recombinant P. griseoroseum strain 105 was 112 times higher than that of P. griseoroseum PG63 grown in sugarcane juice. Cellulases and proteases were not detected in the culture filtrate, and evaluation for extracellular proteins in the culture medium by SDS–PAGE showed the presence of a 36 kDa predominant band, similar to the molecular mass estimated from the nucleotide sequence of plg1 gene for PL of P. griseoroseum strain 105. This recombinant strain provides the advantage of PL production, which predominates over other extracellular proteins usually present in most commercial pectinase preparations, using sugarcane juice as a substrate of low cost.
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    The minimal regulatory region necessary for the expression of the Penicillium griseoroseum plg1 gene
    (Annals of Microbiology, 2015-06) Bazzolli, Denise Mara Soares; Reis, Klédna Constância Portes; Teixeira, Janaina Aparecida; Ribon, Andréa Oliveira Barros; Queiroz, Marisa Vieira de; Araújo, Elza Fernandes de
    The expression of the Penicillium griseoroseum plg1 gene is induced by citric pectin and repressed by glucose. In this work, the minimal region of the plg1 gene promoter essential for expression in pectin and sucrose plus yeast extract was identified by using constructs containing the gfp ORF under control of the plg1 gene promoter. The fragment A (283 bp) is essential for plg1 expression in sucrose plus yeast extract. Fragment B (309 bp plus 184; core promoter) was critical for expression in pectin and abolished the catabolic repression by glucose. Therefore, the fragment of 776 bp (fragment A and B) is essential for the expression of the plg1 gene in natural inducing conditions (pectin as carbon source) and in sucrose plus yeast extract. The fragment B is a promising minimal promoter usable for heterologous expression in filamentous fungi, since genes that contain it could be activated by the presence of peel from citric fruits (which contains citric pectin) and are not affected by glucose in these agricultural by-products.
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    Improved pectinase production in Penicillium griseoroseum recombinant strains
    (Journal of Applied Microbiology, 2011-06-27) Teixeira, J.A.; Gonçalves, D.B.; Queiroz, M.V. de; Araújo, E.F. de
    To obtain recombinant strains of Penicillium griseoroseum that produce high levels of pectin lyase (PL) and polygalacturonase (PG) simultaneously. A strain with high production of PL was transformed with the plasmid pAN52pgg2, containing the gene encoding PG of P. griseoroseum, under control of the gpd promoter gene from Aspergillus nidulans. Southern blot analysis demonstrated that all strain had at least one copy of pAN52pgg2 integrated into the genome. The recombinant strain P. griseoroseum T20 produced levels of PL and PG that were 266‐ and 27‐fold greater, respectively, than the wild‐type strain. Furthermore, the extracellular protein profile of recombinant T20 showed two protein bands of c. 36 and 38 kDa, associated with PL and PG, respectively. This recombinant strain T20 produces PL and PG using carbon sources of low costs, and an enzyme preparation that is free of cellulolytic and proteolytic activities. PL and PG play an important role in the degradation of pectin. Owing to their use in the juice and wines industries, there is a growing interest in the inexpensive production of these enzymes. This work describes an efficient system of protein expression and secretion using the fungus P. griseoroseum.