Bacterial Lignin Peroxidase Mediated Biobleaching and Biodegradation of Paper and Pulp Mill Effluent

Abstract

Large amount of lingo-cellulosic waste generated by forestry, agricultural practices, paper-pulp industries and textile dye-stuff industries poses a severe environmental pollution problem. Paper factory effluent is one of the major pollutants on the earth because it is highly coloured. The persistent dark brown colour is due to dissolved lignin based synthetic, aromatic and chlorinated compounds derived from the blow heat condensate, pulp decker washing, chlorine and alkali bleach waste, black liquor spillage and foul evaporator condensate. Selection of correct and ecofriendly treatment method for paper-pulp mill waste-water prior to discharge into the environment is still a matter of concern. In the present study, the application of the lignin peroxidase enzyme as crude extracts of the bacterial isolate cultures was reported as an effective tool in biobleaching and biodegradation of paper pulp mill effluent which was measured spectrophotometrically. The isolates Sphingomonas paucimobilis and Corynebactrium jeikeium were found to be an efficient biobleaching agent as compared to the other isolates studied. They showed 91.32%, 86.57%, 84.21% and 83.82%, 82.43% and 78.94% biobleaching respectively when applied as axenic cultures while the mixed consortia being the most effective showed the biobleaching in the range of 91.61%, 89.47% and 86.84% of the effluent 50%, 75% and 100% respectively.