Mutagenic Effect of Gamma Irradiation on Phenotype and Enzyme Activities in Aspergillus niger

THIS STUDY aimed at investigating the effect of gamma irradiation…… on the phenotypic characters of Aspergillus niger and its impacton the activities of some enzymes such as lipase, protease, cellulase,pectinase and amylase. Two phenotypically different mutants wereobtained after gamma irradiation at doses of 1 and 3 kGy. SEMmicroscopy showed clear morphological changes in conidiophores,conidial heads and spores among all strains. The activities of lipase,protease and cellulase in both mutants become less than that of theparent strain, while, pectinase showed no significant difference amongthe tested strains. Amylase activity was enhanced by gammairradiationin the mutants. The obtained mutants were molecularlycharacterized using RAPD-PCR. The results demonstrated theoccurrence of polymorphic pattern between parent and mutant strainsdue to change in the genetic makeup.