IMPROVEMENT OF P. CHRYSOGENUM BY UV MUTATION FOR OVERPRODUCTION OF CELLULASE AND LIGNINASE

Abstract

The improvement of microbial strains for the overproduction of lignocellulolytic enzymes production by mutagenesis has attracted attention in the commercial fermentation industry. The present study was designed to modify a Penicillium chrysogenum strain, overproduce cellulase and ligninase, and see the relationship between exposure time and distance of delivering UV rays to fungal strains for the improvement of enzyme production.UV radiation source was placed above the surface of P. chrysogenum suspension spores. Radiation was delivered at 30W at various distances between 10cm ~ 50cm for 10 ~ 60mins intervals of 10min. Mutants obtained from the irradiation were selected and cultured in mineral salt media for enzyme assays. Reducing sugars released were determined as well as enzyme activity of the cellulase (FPase and CMCase) and ligninase (Laccase, MnP, LiP). Growths on plates were also monitored and studied.The FPase and CMCase activity of the mutant strains were two folds higher than that of the parent strains. Similar trend was observed with the LiP, MnP and Laccase where there was 5 fold, 15 fold, and 9.6 fold respectively.There was no significant difference in FPase activities (P>;0.05) for the different exposure time and distance from source of radiation, however, there was in the case of CMCase. There was no significant difference (P>;0.05) for Laccase and Manganese Peroxidase, however there was significant difference for Lignin peroxidase. The distance at which Ultraviolet Irradiation is delivered and the exposure time could significantly affect the mutation of fungi for production of lignocellulolytic enzymes.