Improvement of industry-applied rifamycin B-producing strain, Amycolatopsis mediterranei, by rational screening.

Zhi Hua Jin, Jiang Ping Lin, Zhi Nan Xu, Pei Lin Cen

Index: Int. J. Syst. Evol. Microbiol. 57(Pt 8) , 1876-80, (2007)

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Abstract

An industrially applied rifamycin B-producing strain, Amycolatopsis mediterranei XC 1-02, was used for further screening. A special mutation and screening procedure was adopted to select a strain, which can alleviate the inhibition caused by both aromatic amino acid and p-hydroxybenzoic acid in the pathway of rifamycin B biosynthesis as well as enhance the production of propionate, one of the precursors of rifamycin B biosynthesis. By the above methods, a strain A. mediterranei XC 9-25 was obtained, and its rifamycin B productivity in shaking flask reaches 10 g/L, which is 2.38 times higher than that of the ancestral strain XC 1-02. The productivity of rifamycin B fed-batch fermentation in 60000 L fermentor with A. mediterranei XC 9-25 reached 19.11 g/L.