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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847

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Data inicial: 2008Data final: 2009Assunto: search.filters.subject.Penicillium griseoroseum

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    Covalent immobilization of α-Galactosidase from Penicillium griseoroseum and its application in Oligosaccharides Hydrolysis
    (Applied Biochemistry and Biotechnology, 2008-10-21) Falkoski, Daniel Luciano; Guimarães, Valéria Monteze; Queiroz, Marisa Vieira de; Araújo, Elza Fernandes de; Almeida, Maíra Nicolau de; Barros, Everaldo Gonçalves de; Rezende, Sebastião Tavares de
    Partially purified α-Galactosidase from Penicillium griseoroseum was immobilized onto modified silica using glutaraldehyde linkages. The effective activity of immobilized enzyme was 33%. Free and immobilized α-galactosidase showed optimal activity at 45 °C and pH values of 5 and 4, respectively. Immobilized α-galactosidase was more stable at higher temperatures and pH values. Immobilized α-galactosidase from P. griseoroseum maintained 100% activity after 24 h of incubation at 40 °C, while free enzyme showed only 32% activity under the same incubation conditions. Defatted soybean flour was treated with free and immobilized α-galactosidase in batch reactors. After 8 h of incubation, stachyose was completely hydrolyzed in both treatments. After 8 h of incubation, 39% and 70% of raffinose was hydrolyzed with free and immobilized α-galactosidase respectively. Immobilized α-galactosidase was reutilized eight times without any decrease in its activity.
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    Gel mobility shift scanning of pectin-inducible promoter from Penicillium griseoroseum reveals the involvement of a CCAAT element in the expression of a polygalacturonase gene
    (Genetics and Molecular Biology, 2008-07-25) Ribon, Andréa de O.B.; Ribeiro, João Batista; Gonçalves, Daniel B.; Queiroz, Marisa V. de; Araújo, Elza F. de
    Previous reports have described pgg2, a polygalacturonase-encoding gene of Penicillium griseoroseum, as an attractive model for transcriptional regulation studies, due to its high expression throughout several in vitro growth conditions, even in the presence of non-inducing sugars such as sucrose. A search for regulatory motifs in the 5' upstream regulatory sequence of pgg2 identified a putative CCAAT box that could justify this expression profile. This element, located 270 bp upstream of the translational start codon, was tested as binding target for regulatory proteins. Analysis of a 170 bp promoter fragment by electrophoretic mobility shift assay (EMSA) with nuclear extracts prepared from mycelia grown in pectin-containing culture medium revealed a high mobility complex that was subsequently confirmed by analyzing it with a double-stranded oligonucleotide spanning the CCAAT motif. A substitution in the core sequence for GTAGG partially abolished the formation of specific complexes, showing the involvement of the CCAAT box in the regulation of the polygalacturonase gene studied.