Characterization of a pathway-specific activator of milbemycin biosynthesis and improved milbemycin production by its overexpression in Streptomyces bingchenggensis

Abstract

A LAL regulator, MilR, was characterized in the mil gene cluster of S. bingchenggensis BC04. MilR could activate milbemycin biosynthesis through direct interaction with the promoter of the milA4-E operon and that of milF. Overexpression of milR increased milbemycin A3/A4 production by 38 % compared with the parental strain BC04, suggesting that genetic manipulation of this activator gene could enhance the yield of antibiotics.