Cloning, expression and characterization of β-xylosidase from Aspergillus niger ASKU28.

β-Xylosidases catalyze the breakdown of β-1,4-xylooligosaccharides, which are produced from degradation of xylan by xylanases, to fermentable xylose. Due to their important role in xylan degradation, there is an interest in using these enzymes in biofuel production from lignocellulosic biomass. In this study, the coding sequence of a glycoside hydrolase family 3 β-xylosidase from Aspergillus niger ASKU28 (AnBX) was cloned and expressed in Pichia pastoris as an N-terminal fusion protein with the α-mating factor signal sequence (α-MF) and a poly-histidine tag.