Optimization of Culture Medium for Rifamycin SV Production by Amycolatopsis kentuckyensis 22-187

Abstract

A new strain harboring 3-amino-5-hydroxy benzoic acid (AHBA) synthase gene was isolated from China soil and taxonomically was identified as Amycolatopsis kentuckyensis 22-187. It was confirmed that the 22-187 strain mainly produced rifamycin SV and B by chemical identification. The culture medium for Amycolatopsis kentuckyensis 22-187 was optimized on a shake-flask scale by using Plackett-Burman design and response surface methodology for enhanced rifamycin SV production. The Plackett-Burman design indicated that the main factors that positively affect rifamycin SV production by Amycolatopsis kentuckyensis 22-187 were the concentration of glucose and peptone in the fermentation medium. A final concentration of 11.02% (w/v) glucose and 0.98% (w/v) of peptone was found to be best for rifamycin production. Using an optimized fermentation medium (Ammonium Citrate 0.5%, K₂HPO₄ 0.1%, MgSO₄ 0.1%, CaCO₃ 0.5%, glucose 11.02%, peptone 0.89%) the titer of fermentation of rifamycin SV was increased two folds comparing with that in the initial medium by HPLC analysis. But the rifamycin B production keeps the same as in initial medium.