High levels of [beta]-xylosidase in Thermomyces lanuginosus: potential use for saccharification

Abstract

A new strain of Thermomyces lanuginosus was isolated from the Atlantic Forest biome, and its β-xylosidases optimization in response to agro-industrial residues was performed. Using statistical approach as a strategy for optimization, the induction of β-xylosidases activity was evaluated in residual corn straw, and improved so that the optimum condition achieved high β-xylosidases activities 1003 U/mL. According our known, this study is the first to show so high levels of β-xylosidases activities induction. In addition, the application of an experimental design with this microorganism to induce β-xylosidases has not been reported until the present work. The optimal conditions for the crude enzyme extract were pH 5.5 and 60 °C showing better thermostability at 55 °C. The saccharification ability of β-xylosidase in the presence of hemicellulose obtained from corn straw raw and xylan from beechwood substrates showed a xylo-oligosaccharide to xylose conversion yield of 80 and 50%, respectively, at 50 °C. Our data strongly indicated that the β-xylosidases activities was not subjected to the effects of potential enzyme inhibitors often produced during fermentation process. These data suggest the application of this enzyme studied for saccharification of hemicellulose, an abundant residue in the American continents, thus providing an interesting alternative for future tests for energy production.