Purification and Properties of Thermostable Xylanase from Talaromyces byssochlamydoides YH-50

Abstract

Thermostable xylanase from Talaromyces byssochlamydoides YH-50 was fractionated into three components, tentatively named X-a, X-b-I and X-b-II during the purification steps. X-a, X-b-I and X-b-II were further purified by consecutive column chromatographies until found to be in homogeneous states on disc electrophoresis. X-a, X-b-I and X-b-II contained 36.6%, 31.5% and 14.2% carbohydrate residues, respectively. The carbohydrate residues were glucose, mannose and fucose. X-a, X-b-I and X-b-II were optimally active at 7075°C and pH 4.55.5. X-a, X-b-I and X-b-II retained 65, 54 and 30%, respectively, of the original activity after heating at 95°C for 5 min. The activities of X-a, X-b-I and X-b-II were considerably inhibited by HgCl₂ and KMnO₄. The hydrolysis products from xylan with X-a were xylose, arabinose, glucose, xylobiose and other xylooligosaccharides, whereas the hydrolysis products from xylan with X-b-I and X-b-II were xylose and xylobiose.