HIGH-ACTIVITY XYLANASE FROM THERMOTOLERANT STREPTOMYCES-T7 - CULTURAL CONDITIONS AND ENZYME PROPERTIES

A thermotolerant Streptomyces T7 produced 70-72 U/ml of extracellular xylanase activity when grown at 50-degrees-C in submerged culture, in a medium containing 5% wheat bran as a carbon source. Among the various sugars tested, maltose showed the highest activity of 8 U/ml. Pure xylan was less effective as an inducer as compared to wheat bran. Ammonium sulphate at a concentration of 0.7% was found to be optimum for maximum yield of the enzyme. The optimum period and pH for maximum production were 72h and 7.0, respectively. The culture filtrate was devoid of amylase, cellulase and beta-xylosidase activity. The xylanase was exceptionally stable and did not show any loss in activity after storage at 50-degrees-C at pH 5.0 for 6 days.