Biochemical characterization of an organic solvent- and salt-tolerant xylanase and its application of arabinoxylan-oligosaccharides production from corn fiber gum

A endo-xylanase, of the glycoside hydrolase family 10 from Schizophyllum commune DB01, was expressed in P. pastoris. Recombinant xylanase (Scxyn5) retained above 80 % maximum activity in 10 % dimethyl sulfoxide and retained 90 % maximum activity in 5 M NaCl on the substrate of birchwood xylan. The effect of NaCl on the catalytic activity of Scxyn5 was significantly different toward various substrates, which was caused by the difference of monosaccharide composition and sturcture of the substrates. Furthermore, when corn fiber gum (CFG) was used as a substrate, the catalytic activity of Scxyn5 increased by 1.3-2.03 times in 1-5 M NaCl. Based on response surface methodology, the highest catalytic activity of Scxyn5 in hydrolyzing CFG were achieved with enzymatic temperature of 50 degrees C, pH value of 6.0, and 4 M NaCl. These properties of Scxyn5 suit the arabinoxylan-oligosaccharides (AXOs) preparation from CFG and some other potential applications in food industry.