Engineering the precursor supply pathway in Streptomyces gilvosporeus for overproduction of natamycin / 生物工程学报

Natamycin is a safe and efficient antimycotics which is widely used in food and medicine industry. The polyene macrolide compound, produced by several bacterial species of the genus Streptomyces, is synthesized by type Ⅰ polyketide synthases using acetyl-CoA, malonyl-CoA, and methylmalonyl-CoA as substrates. In this study, four pathways potentially responsible for the supply of the three precursors were evaluated to identify the effective precursor supply pathway which can support the overproduction of natamycin in Streptomyces gilvosporeus, a natamycin-producing wild-type strain. The results showed that over-expressing acetyl-CoA synthetase and methylmalonyl-CoA mutase increased the yield of natamycin by 44.19% and 20.51%, respectively, compared with the wild type strain under shake flask fermentation. Moreover, the yield of natamycin was increased by 66.29% compared with the wild-type strain by co-overexpression of acetyl-CoA synthetase and methylmalonyl-CoA mutase. The above findings will facilitate natamycin strain improvement as well as development of strains for producing other polyketide compounds.

STREPTOMYCIN RESISTANCE MUTATION——A STUDY ON THE BREEDING OF HIGH NATAMYCIN-PRODUCING STRAIN / 微生物学通报

A method of streptomycin resistance screening was applied to improve t he productivity of Natamycin by Streptomyces gilvosporeus(ATCC13326) The sp ores treated with UV light were regenerated on agar plates containing 0 6?g/mL stre p tomycin 122 streptomycin resistant(str) mutants were obtained The Natamycin y iel ds of 13 mutants were higher than the original strain The mutants with high Na t amycin productivity were screened at a high frequency(10 6%) The highest one that demonstrated 1 46 times that of the original strain in Natamy cin productivity was obtained