Produção de xilanase por fungos filamentosos isolados de solo de área de caatinga
Carregando...
Data
2006-07-28
Autores
Simões, Maria Lúcia Garcia [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Neste estudo, foram isoladas 67 linhagens de fungos filamentosos de solo de área de caatinga, sendo as coletas efetuadas em períodos seco e chuvoso, com o objetivo de se conhecer a biodiversidade deste bioma não explorado e avaliar o potencial destes fungos na produção de xilanase. Algumas linhagens não foram identificadas por inexistência de metodologias específicas e outras foram identificadas através de métodos microscópicos e bioquímicos. Foi efetuada uma triagem dos fungos potencialmente produtores desta enzima em meio de Vogel contendo xilano 1% como única fonte de carbono e avaliou-se através do Método Turbidimétrico Automatizado (Bioscreen-C), a melhor fonte de carbono para crescimento dos fungos selecionados. Os resultados obtidos nos cultivos em MFS, foram inexpressivos quando comparados aos obtidos em MFT. Os melhores produtores de xilanase em MFT foram cultivados em meio líquido de Vogel e MFT com adição individual de outras fontes de carbono a 1% (carbometilcelulose- CMC, xilano e a melhor fonte de carbono para crescimento, determinada pelo Bioscreen-C) em temperaturas apropriadas, pH 5, por 5 dias, inóculo de 1 x 107 esporos/mL. O CMC causou repressão catabólica na síntese de xilanase por estes fungos tendo a adição do xilano apresentado o mesmo efeito, com exceção de Trichoderma viride, que teve sua atividade aumentada para 143,0 U/mL e Aspergillus niger 11 que teve sua atividade aumentada de 33,4 U/mL para 57,1 U/mL.
In this study, 67 strains of filamentous fungi were isolated from caatinga area, the collections were performed during the dry and rainy period, aiming to know the biodiversity of this not explored bioma and to evaluate the potential of these fungi to produce xylanase. Some of the strains were not identified due to the lack of specific methodologies and others were identified through microscopic and biochemical methods. A selection of the fungi which were considered potentially producers of xylanase was carried out in Voguel medium containing 1% of xylan as an only carbon source, and through a Automatized Turbidimetric Method (Bioscreen - C) the best carbon source for the fungi growth was evaluated. The results obtained in SBM were not expressive when compared to the ones obtained in WBM. The best xylanase producers in WBM were cultivated in Voguel liquid medium and WBM adding individually other carbon sources at 1% (carboxymethylcellulose -CMC; xylan; and the best growth carbon source determined by Bioscreen-C) at appropriated temperatures, pH 5,0 ; for 5 days, and a spore concentration of 1 x107 spores/mL. The CMC addition caused catabolic repression in xylanase production by these fungi, xylan addition showed the same effect, but Trichoderma viride 13 and Aspergillus niger 11 which have their activities increased from 39,21 U/mL to 143,0 U/mL and from 33,4 U/mL to 57,1 U/mL, respectively.
In this study, 67 strains of filamentous fungi were isolated from caatinga area, the collections were performed during the dry and rainy period, aiming to know the biodiversity of this not explored bioma and to evaluate the potential of these fungi to produce xylanase. Some of the strains were not identified due to the lack of specific methodologies and others were identified through microscopic and biochemical methods. A selection of the fungi which were considered potentially producers of xylanase was carried out in Voguel medium containing 1% of xylan as an only carbon source, and through a Automatized Turbidimetric Method (Bioscreen - C) the best carbon source for the fungi growth was evaluated. The results obtained in SBM were not expressive when compared to the ones obtained in WBM. The best xylanase producers in WBM were cultivated in Voguel liquid medium and WBM adding individually other carbon sources at 1% (carboxymethylcellulose -CMC; xylan; and the best growth carbon source determined by Bioscreen-C) at appropriated temperatures, pH 5,0 ; for 5 days, and a spore concentration of 1 x107 spores/mL. The CMC addition caused catabolic repression in xylanase production by these fungi, xylan addition showed the same effect, but Trichoderma viride 13 and Aspergillus niger 11 which have their activities increased from 39,21 U/mL to 143,0 U/mL and from 33,4 U/mL to 57,1 U/mL, respectively.
Descrição
Palavras-chave
Enzimas, Fungos, Caatinga, Xilanase, Xylanase, Filamentous fungi
Como citar
SIMÕES, Maria Lúcia Garcia. Produção de xilanase por fungos filamentosos isolados de solo de área de caatinga. 2006. xviii, 133 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, 2006.