Regulation of slnN gene in salinomycin biosynthesis

Abstract:

[Objective] To study the potential of regulatory gene slnN upstream of salinomycin biosynthesis gene cluster. [Methods] We used genetic manipulation technique to knock out and overexpress the slnN gene in the original strain Streptomyces albus BK3-25. Then, using inhibition zone test and fermentation experiment, we detected the changes of the production of salinomycin biosynthesis in different derivative strains. At the same time, we used qRT-PCR technique to analyze the difference of the structural gene expression between the derived strains and the original strain. [Results] The production of salinomycin was increased by about 35% in the slnN gene-deleted strain (slnNDM), whereas the production of salinomycin was decreased by about 43% in the slnN gene-overexpressing strain (slnNOE). qRT-PCR analysis revealed that loss of slnN gene caused up-regulation of slnO and slnA1 genes. The slnN gene overexpression, on the one hand down-regulated the expression of slnO and slnA1 gene, on the other hand caused slnT1 and slnF gene up-regulation. [Conclusion] The slnN gene has a significant negative regulatory effect on the biosynthesis of salinomycin.