Abstract

K.V.V.S.N. Bapiraju, P. Sujatha, P. Ellaiahand T. Ramana

The purpose of the present investigation is to enhance production of biomedically important enzyme lipase by subjecting the indigenous lipase producing strain Rhizopus sp. BTS-24 to improvement by natural selection and random mutagenesis (UV and N-methyl-N’-nitro-N-nitroso guanidine, NTG). The isolation of mutants and the lipolytic activity of selected mutants were described. The best natural selectant BTNS12 showed 110% higher lipase activity than the wild strain (BTS-24). The lipase yield of the best UV mutant BTUV3 was 164% higher than the parent strain (BTNS12) and 180% times higher than the wild strain (BTS-24). Also, the lipase yield of the best NTG mutant BTNT2 was 133 % higher than the parent strain (BTUV3) and 232% higher than the wild strain (BTS-24). The results indicated that UV and NTG were effective mutagenic agents for strain improvement of Rhizopus sp. BTS-24 for enhanced lipase productivity.