Improved thermostability of an acidic xylanase from Aspergillus sulphureus by combined disulphide bridge introduction and proline residue substitution.

ABSTRACT: As a feed additive, xylanase has been widely applied in the feed of monogastric animals, which contains multiple plant polysaccharides. However, during feed manufacture, the high pelleting temperatures challenge wild-type xylanases. The aim of this study was to improve the thermostability of Aspergillus sulphureus acidic xylanase. According to the predicted protein structure, a series of disulphide bridges and proline substitutions were created in the xylanase by PCR, and the mutants were expressed in Pichia pastoris. Enzyme properties were evaluated following chromatographic purification. All the recombinant enzymes showed optima at pH 3.0 and 50 °C or 55 °C and better resistance to some chemicals except for CuSO₄. The specific activity of the xylanase was decreased by introduc

SUBMITTER: Yang W 

PROVIDER: S-EPMC5431495 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature