K. SELVAMP, K.P. SARITHA, K. SWAMINATHAN, M. MANIKANDAN, K. RASAPPAN AND E CHINNASWAMV
Abstract
Two white rot fungi Fomes lividus and Tra metes versicolor, isolated from the Western Ghats region of Tamilnadu, India, were used to treat Eucalyptus grandis wood chips and hard wood Kraft pulp. Hand sheets that were prepared by conventional chemicals methods and had 20 kappa points and 14.0 ISO brightness were used as a control. Hand sheets prepared by fungal pretreatment followed by treatment with 50% Na20 chemicals (as that of control) had 15 and 14 kappa points 16 and 17 ISO brightness, of F.lividus and T.versicolor respectively. Biobleaching and delignification of hard wood and kraft pulp (HWKP) by pretreatment with F.lividus and Tversicolor in shaking culture reduced the kappa number by 38.7 and 67.7% and increased ISO brightness by 29.8 and 29.9% of on 6"' and on 5'h day, respectively. Partially purified enzymes of these fungal lignin peroxidase (LiP), manganese dependent peroxidase (IvInP) laccase and mixture of these enzymes were treated to hard wood kraft pulp. Laccase at 15U/ml of both fungi reduced the kappa number by 36.1% and increased ISO brightness in T. versicolor mixture enzymes by 36.1%. These results revealed and F.lividus and Tversicolor pretreatment could reduce the chemical usage in paper industries without affecting the paper quality.