Genetic Engineering of Streptomyces natalensis VTCC-A-3245 to Improve Its Natamycin Production

Abstract

Natamycin, a polyene compound with broad-spectrum activity against yeasts and fungi, was firstly found in Streptomyces natalensis. Because of its low toxicity to mammalian cells, natamycin is widely used in food industry and medicine to prevent fungal growth. Although natamycin has been used worldwide, this antifungal compound has not been produced in Vietnam. One of the reasons is that we do not own any industrial-scale production strain. In order to develop such production strain, strain improvement must be involved. Therefore, we carried out the study “Genetic engineering of Streptomyces natalensisVTCC-A-3245 to improve its production of natamycin”. In this study, we introduced a copy of the gene pimM, a positive regulator gene in the natamycin biosynthetic pathway, into S. natalensischromosome, hence boosting the expression of the structural genes, resulting in the increase of natamycin production. As a result, a recombinant pSET152 plasmid containing pimMwas constructed and transformed successfully into E. coli ET12567. After conjugation, a S. natalensismutant carrying an additional copy of pimMwas obtained. The result showed that the level of natamycin produced by the S. natalensismutant strain increased 3 fold compared to the S. natalensiswildtype strain