Production and characterization of thermostable xylanase from Talaromyces byssochlamydoides YH-50.

Abstract

Strain YH-50 from a thermophilic fungus isolated from compost heaps produced the highest amount of thermostable xylanase among 180 isolates tested. This xylanase-producing strain YH-50 was identified as Talaromyces byssochlamydoides Stolk & Samson by taxonomical characteristics. When it was cultivated in solid wheat bran medium containing xylan as an additive carbon source, the maximal amount of thermostable xylanase was produced after 3 days at 50°C. This culture filtrate hydrolyzed 90 % of xylan as xylose, and the sugars formed were xylose, arabinose, glucose and galactose. The optimal pH and temperature were 5.5 and 70°C, respectively. The enzyme was quite stable after heating at 65°C for 5 min and retained 55 % of original activity after heating at 95°C for 5 min.