PRODUCTION OF XYLANASE BY PENICILLIUM SP. AND ITS BIOBLEACHING EFFICIENCY IN PAPER AND PULP INDUSTRY

The main objective of this study is to evaluate the ability of production of xylanase by a fungal strain Penicillium sp. isolated from decaying wood. Xylanases are hydrolytic enzymes produced by many microorganisms which catalyze the hydrolysis of xylan polymer to xylose monomer. The xylanase production was carried out under submerged fermentation xylose as the main substrate, and the enzyme yield was regularly monitored. Maximum xylanase production was observed on the 4^th day of incubation with 123.1 U/ml. The protein secretion was high on the 6^th day with 787 μg/ml; total sugar was on the 7^th day of incubation (982 μg/ml). Among natural substrates used in this study, corn cobs amended medium had yielded more xylanase production by Penicillium sp. after 6 days of incubation (167.2 U/ml) followed by sawdust and rice bran (128.1 and 120.8). The crude enzyme was used in bleaching of paper pulp and in biobleaching sample kappa number was reduced from 23.1 to 20.8 and brightness was increased to 40.1 from 39.2. It was also observed that chromophores and hydrophobic compounds were removed in xylanase treated pulp samples. Thus by this study, it is highlighted that xylanase by present fungus Penicillium sp. would be useful as a promising biobleaching agent in paper and pulp industry.