Evaluation of brilliant green decolorization by LiP purified from a novel Penicillium chrysogenum isolated from Similipal forest soil, Odisha.

Lignin peroxidase (LiP) is a haem-containing microbial ligninolytic enzyme that has gained much attention for its potential application to degrade industrial effluents. In the current study, seven fungi (SLF1-7) showing ligninolytic activity were isolated from Similipal forest soil, and screened for LiP activity. SLF3 showed the highest LiP activity (3.351 U/mL.min) at un-optimized conditions and was identified as P. chrysogenum using 18S rRNA sequencing. The production of enzyme was optimized using Response Surface Methodology. LiP activity of P. chrysogenum was enhanced to 9.38 U.mL^-1.min (2.79 folds) at pH 6, temperature 37.5 °C, substrate concentration 1.75%, and time 108 h. The LiP enzyme was purified by ammonium sulfate precipitation followed by dialysis and Sephadex G-100 column chromatography. The purified protein showed a single band of approximately 40 kDa by SDS-PAGE analysis. The purified LiP also showed the highest catalytic efficiency with K_m of 0.316 M and V_max of 147.059 U/mL.min. The purified LiP reduced brilliant green color (69.53 ± 0.003%) after 80 min of incubation at 37 °C and pH 6.0. It is apparent from the study that the strain P. chrysogenum has significant potential in degrading brilliant green, which can be explored for bioremediation applications of industrial dyes.