Abstract
The lignin mineralizing enzymes system of white rot fungi has tremendous catalytic prospect for oxidative bioremediation of a number of toxic pollutants and many other industrial uses. Immobilization enables the reuse of enzymes and making them industrially relevant and economical biocatalysts. Schizophyllum commune IBL-06 was cultivated for the secretion of lignin peroxidase (LiP) in pre-optimized solid state fermentation medium of corn stover. A high yield of lignin peroxidase (1347.3 U/mL) was recorded in crude culture supernatant. LiP was purified (5.65 folds) by a pre-standardized four step protocol comprising ammonium sulphate fractionation, dialysis, DEAE cellulose ion exchange and Sephadex G-100 column chromatography. The 38 kDa single polypeptide S. commune IBL-06 LiP migrating as a single clear band on both native and SDS-PAGE gels. The purified enzyme was then immobilized on chitosan beads activated with gluteraldehyde (cross-linker). Scanning electron microscopy (SEM) was conducted for the confirmation of LiP attachment on chitosan beads. The highest textile dye decolorization (95.45%) potential was observed with chitosan-immobilized enzyme at 30 degrees C without hemolytic toxicity. The chitosan beads-LiP retained approximately more than 70% activity after three repeated runs that gradually decreased to 35 % after 7th cycle of reusability. The immobilized LiP was found to show superior dye removal properties as compared to free LiP. Higher thermo stability, lower Kmand high V-max features of chitosan beads immobilizedLiP suggested its suitibility for variousbiotechnological and industrial applictaions.