Engineering Bafilomycin High-Producers by Manipulating Regulatory and Biosynthetic Genes in the Marine Bacterium .

Bafilomycin A is the representative compound of the plecomacrolide natural product family. This 16-membered ring plecomacrolide has potent antifungal and vacuolar H-ATPase inhibitory activities. In our previous work, we identified a bafilomycin biosynthetic gene cluster () from the marine bacterium ATCC BAA-1276, wherein a family regulatory gene and an family regulatory gene were revealed based on bioinformatics analysis. In this study, the positive regulatory roles of and for bafilomycin biosynthesis are characterized through gene inactivation and overexpression. Compared to the wild-type strain, the knockout of either or completely abolished the production of bafilomycins. The overexpression of or led to 1.3- and 0.5-fold increased production of bafilomycins, respectively. A genetically engineered strain (SLO-08) with overexpression and inactivation of the biosynthetic genes and , solely produced bafilomycin A with the titer of 535.1 ± 25.0 mg/L in an optimized fermentation medium in shaking flasks. This recombinant strain holds considerable application potential in large-scale production of bafilomycin A for new drug development.