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

Strain YH-50 from a thermophilic fungus isolated from compost heaps produced the highest amount of thermostable xylanase among 1 80 isolates tested.This xylanase-producing strain YH-50 was identified as Talaromyces byssochlamydoides Stolk & Samson by taxonomical characteristics.Whenit was cultivated in solid wheat bran mediumcontaining xylan as an additive carbon source, the maximalamount of thermostable xylanase was produced after 3 days at 50°C.This culture filtrate hydrolyzed 90%ofxylan 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.Wehave been considered that thermophilic