Cellulases are naturally occurring enzymes to degrade cellulose into simpler components which are used in wide industrial bio-products. The activity of Cellulase enzymes can be enhanced through various mutations and modifications. In this study, cellulase from Aspergillus niger was targeted for mutation by physical and chemical methods using UV radiations and ethyl methane sulfonate (EMS), respectively. During physical mutagenesis, the maximum enzyme activity (322 µmol/mL/min) was observed at 10 min UV irradiation as compared to the control (94 µmol/mL/min), while during chemical mutagenesis, the maximum enzyme activity (390 µmol/mL/min) was observed after treatment of microbial culture with 150 µg/mL concentration of EMS. The enzyme activity was further increased (428.5 µmol/mL/min) by combined mutagenesis including 10 min UV irradiation followed by treatment of culture with 150 µg/mL concentration of EMS. Hence, it was found that treating fungal cultures with physical, chemical and combined mutagenesis can significantly enhance their enzyme activities.

Key words: Aspergillus niger, Cellulase, Physical mutagenesis, Chemical mutagenesis, Combined mutagenesis