Department of  Indian Institute of Petroleum, Uttarakhand, India

Lignin, a high molecular weight, structurally complex carbohydrate having stable linkages due to non-hydrolysable bonds, is difficult to breakdown, and serve as a source of pollution from pulp-paper industrial effluent, as it has intense unaesthetic brown color, hydrophobic in nature with poor mechanical properties. Colored effluents released from various pharmaceutical, textile and other dye-based industries contain mixture of dyes, which may be hazardous to various life forms. Extracellular enzymes for instance lignin peroxidases have potential ligninolytic activity and also serve in biobleaching of effluents containing complex aromatic dyes. From various pharmaceuticals and textile industries 75 isolates were screened for ligninolytic activity, out of which four bacterial isolates Bacillus subtilis, Pseudomonas sp., Bacillus megaterium and Arthobacter sp. were found to decolorize lignin, and also have a potential dye-degrading activity. Percentage decolorisation of Lignin was 85.49%, 84.5%, 82.74 and 87.64% respectively, whereas percentage decolorization of dye due to enzymatic activity was 91.66%, 80.2%, 90.62% and 94.79% respectively.