biobleaching of kraft pulp

A thermoalkalophilic and cellulase free xylanase produced from Arthrobacter sp. MTCC 5214 in solid state fermentation using wheat bran as a carbon source was evaluated for prebleaching of kraft pulp. The UV absorption spectrum of the compounds released by enzyme treatment showed a characteristic peak at 280 nm indicating the presence of lignin in the released coloring matter. Enzymatic prebleaching of kraft pulp showed 20 % reduction in kappa number of the pulp without much change in viscosity. Enzymatic treatment reduced the amount of chlorine by 29 % without any decrease in brightness. The viscosity of xylanase treated pulp was 4.0 p. where as of the pulp treated exclusively with chlorine was 4.1 p