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

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.