Isolation of Bacterial Strain from Sediment Core of Pulp and Paper Mill Industries for Production and Purification of Lignin Peroxidase (LiP) Enzyme

Five bacterial strains were isolated and purified (CSA101 to CSA105) from the sediment core of the effluent released from the Century Pulp and Paper Mill Ltd., India. These strains were grown in minimal salt medium (MSM) containing pulp (10% as a carbon source). The production of lignin peroxidase, CMCase, Fpase, and xylanase together with protein and reducing sugar by all bacterial strains was observed. All of the bacterial isolates responded differently with respect to growth and ligninocellulolytic enzyme production. The maximum lignin peroxidase (LiP) was obtained from the cell extract of Bacillus sp. (CSA105) strain, which was used for purification, fractionation and characterization. The culture filtrate from Bacillus sp. (CSA105) was purified with ammonium sulfate precipitation. Crude protein was desalted by dialyzing with Tris buffer. The lignolytic enzyme produced in the liquid medium was fractionated by gel filtration on Sephadex G-100. In the present study, 12.4-fold purification of LiP enzyme was obtained and 35.85% yield of lignin peroxidase was achieved in the cell extract of Bacillus sp. (CSA105). Lignin peroxidase enzyme plays an important role in lignin degradation process. The ligninolytic enzymes were produced by all of the bacterial strains but maximum lignin peroxidase activity was found in cell extract of CSA105. On the basis of the results obtained, the bacterial strain (CSA105) was found most suitable for the purification of the LiP enzyme.