Evaluation of brilliant green decolorization by LiP purified from a novel <i>Penicillium chrysogenum</i> 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 <i>P. chrysogenum</i> using 18S rRNA sequencing. The production of enzyme was optimized using Response Surface Methodology. LiP activity of <i>P. chrysogenum</i> 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 <i>P. chrysogenum</i> has significant potential in degrading brilliant green, which can be explored for bioremediation applications of industrial dyes.