ABSTRACT
Twenty-four different strains of Streptomyces spp. isolated from Egyptian soil were tested for their ability to produce extracellular xylanases. Of all these isolates a Streptomyces sp. that had the highest potential for xylanolytic activity was chosen. From various morphological, physiological and antagonistic properties, this isolate was found to belong to Streptomyces lividans. Factors affecting xylanase production by this organism in a basal salt medium containing purified sugar-cane bagasse xylan as a sole carbon source were examined. A noticeable increase in enzyme activity was observed in the presence of peptone or soyabean meal. However, a slight increase was noticed with ammonium sulphate. Optimum production for xylanase was achieved after five days incubation on a rotary shaker (180 rpm) at 30 degrees C. The initial pH values were around neutrality. In addition, this organism has high potential for xylanolytic activity when grown on lignocellulosic wastes including corn cobs, wheat bran, peanut shells, sawdust, wheat straw and sugar-cane-bagasse. Partial purification of the enzyme in the culture supernatant was achieved by salting out at 50-80% ammonium sulphate saturation with a purification of 9.03-fold and 57.9% recovery.
