The efficacy of different Pleurotus ostreatus (L.) isolates to treat pulp and paper industrial effluent on a shake flask and fermentor were studied. In the shake flask and fermentor studies, Pleurotus ostreatus decolorized the effluent 69.68% and 66.66% respectively, on 7TH day of incubation. The chemical oxygen demand was reduced by 61.3% by Pleurotus ostreatus on day 7 of incubation. Various cultural conditions including different glucose concentrations, nitrogen sources, pH, temperature and incubation period influence on biomass and different enzymes viz; xylanase, CMCase and laccase...