Penicillium chrysogenum mutants with increased penicillin production under solid and submerged cultures conditions

Abstract EN

Two mutants G2U and G3 were selected from different mutants produced after exposing the parental strain Pencillium chrysogemum IMI 037767 to six rounds of mutation by UV and gatmna rays at different doses.

The mutant G3 was isolated after three rounds of gamma ray and the mutant G2U was selected after two rounds of gamma and one round of UV ray.

The parental strain produced 53 and 86 unit/ml of penicillin, while mutant G2U and G3 produced 61, 272 and 149,229 u/ml under solid state and submerged fermentation conditions, respectively.

It was found that wheat bran was the most convenient solid substrate for penicillin production by solid state fermentation as compared with wood shaves or olive pomace.

The optimum moisture content for the solid culture was 69% and the highest penicillin production from the parent strain and the mutant G2U (87 and 162u/ml)were obtained after 8 days under submerged culture conditions.

While the highest production of penicillin from the parent strain and mutant G3 (93 and 153u/ml) was achieved after 6 days of incubation by solid state fermentation.

The UV mutants gave lower penicillin production than gamma mutants.