Breeding Of Spinosad High Producing Strains Through MPMS Mutagenesis Combined With Antibiotics

Spinosad, produced by aerobic fermentation of saccharopolyspora spinosa, was a new kind of macrolide antibiotic which has high-effective insecticidal activity, efficacy against a wide range of insects and safe for nontarget animal. A fast and high throughput screening method was employed to screen mutant strains through physics mutagenesis combined with antibiotics in order to acquire high producing strains for industrial production.Two approaches were used on the original strain of S. spinosa ASAGF W2 to screen spinosad high producing strains by adding streptomycin(Str), gentamicin(Gen), chloramphenicol(Chl)and rifampicin( Rif) at low concentrations. The first one was inducing different resistance to antibiotics by antibiotic plates successively, which was marked as non-GYM group; As the effect of mutagenesis was determined by pure culture, the second one was inducing next kind of resistance to antibiotic by antibiotic plates after the mutants was isolated and purified through streak plate method,which was marked as GYM group. One mutant named ASAGF 13-8-1 showed enhanced spinosad production by 23.87%, compared to original strain, which have been obtained through five rounds screening from 774 isolates of antibiotic combination Str0.05Gen10 in non-GYM group.Antibiotic combinations of Str0.9Gen14 and Chl2Gen14Rif400Str0.9 were used to screen mutants after the spores of S. spinosa ASAGF 13-8-1 was mutated by MPMS. One mutant named ASAGF14-2 showed enhanced spinosad production by 28.68%, compared to original strain, which have been obtained through five rounds screening from 576 isolates of MPMS combined with the antibiotic combination of Chl2Gen14Rif400Str0.9.In this study, an approach to screen spinosad high yield strains using physics mutagenesis combined with antibiotics was developed. One mutant named ASAGF 14-2 showed accumulatively enhanced spinosad production by 52.55%, compared to original strain ASAGF W2.As the experimental result was effective, it would be of guiding significance to acquaire spinosad high-producing strains that were suitable for industrial production.