Characterization of Enzyme Endoxylanase Produced by Mutants Strains of Aspergillus Awamori K-1

Xylanolytic enzymes of microbial origin have received great attention due to their biotechnological utility and potential applications in a range of industrial processes but the observed effects vary depending on xylanase specificities. The goal of this investigation was to determine the endoxylanase enzyme production ability and molecular characteristics of fungal strains Aspergillus awamori K-1 and its mutant strains A59, A50, A45 and A60. The strains were cultivated in liquid culture with 1% wheat bran and 2% ground corn-cobs as inducer. Maximum enzyme production of parent strain Aspergillus awamori K-1 of 42,35 IU/ml and of mutant strains A59 - 96,91 IU/ml, A50 - 71,67 IU/ml, A45 - 74,04 IU/ml and A60 - 62,59 IU/ml was determined after 72-96 h of cultivation. Extracellular endoxylanase was partially purified from the culture filtrates of five strains, using molecular sieve chromatography with two type of Sephadex-G 50 and G100. The purification conditions were optimized and the main endoxylanase activity was determined in second fraction in case of Sephadex G100. The partial purified enzyme fractions showed the same band for all strains on SDS polyacrylamide gel electrophoresis (SDS-PAGE) with an apparent molecular weight of 32 kDa.