Abstract:[Background] Streptomyces sp. OUCMDZ-3434 was isolated from Enteromorpha prolifera collected from the Zhanqiao Beach, Qingdao, Shandong, and it produced wailupemycins with good α-glycosidase inhibitory activity, but at very low yield. [Objective] To develop the genetic system of marine-derived Streptomyces sp. OUCMDZ-3434 and investigate the role of wblA gene on wailupemycins production. [Methods] Escherichia coli-Streptomyces intergeneric conjugation manipulation was established for Streptomyces sp. OUCMDZ-3434 using pSET152. wblA gene was inactivated by using PCR-targeting strategy. After confirmation by PCR, the fermentation broths of the wild-type and mutant strains were analyzed by HPLC, and morphological differentiation was observed by using phase contrast microscope. [Results] The conjugation method for Streptomyces sp. OUCMDZ-3434 was established and the wblA gene inactivation mutant was constructed. The yield of wailupemycin G in the wblA inactivation mutant was increased by 3-fold compared to that of the wild-type strain. Additionally, the wblA gene mutant lost the ability of sporulation. [Conclusion] The wblA gene in Streptomyces sp. OUCMDZ-3434 negatively regulates the biosynthesis of wailupemycins and is involved in regulation of sporulation as well. These results laid the foundation for yield improvement of wailupemycins by genetic manipulation.
