Abstract: Xylanase, an enzyme that randomly cleaves internal β-1,4-xylosidic linkages of xylan backbone, has
wide applications in feed, food, pulp and paper, and textile industries. In the
present study, gene xynC encoding
xylananse from Aspergillus niger CICIM F0510 was cloned and expressed in Pichia
pastoris, and the recombinant strain GS115 (pPIC-xynC) was subsequently
constructed. At the
shake flask level, the activity of the recombinant enzyme XynC was 1.14 U/mL.
The optimum temperature and pH of XynC was determined to be 30 ℃ and 2.5,
respectively. This enzyme was also stable at 25-40 ℃ or pH 2.0-5.0. K+ slightly enhanced the activity of XynC, whereas Ca2+, Co2+, Mn2+, Zn2+, Cu2+,
Fe3+, Sn2+ EDTA and SDS had different inhibitory effects on its activity. Besides, XynC can hydrolyze pentosan to
yield short chain xylooligosaccharides with degree of polymerization of 3-6.
Such good biochemical properties lay a solid foundation for the applications of
XynC in feed and food fields.