Abstract:A high epothilone B producing mutant SoF5-H23 was screened from Sorangium cellulosum SoF5-76 by combination treatment with UV and NTG. This mutant has good stability of producing epothilone B and production was 79.83 mg/L, which was 1.27 times higher than that of original strain. Plackett-Burman design and the response surface methodology(RSM) were applied to optimize medium for fermentation and conditions. The obtained optimal fermentation conditions were potato starch 4.8 g/L, skim milk powder 2.3 g/L, glucose 0.5 g/L, soybean powder 2 g/L, magnesium sulfate 2 g/L, chlorine calcium 2 g/L, EDTA-Fe3+ 2 mL/L, trace elements 0.5 mL/L, absorbent resin 2%, pH 7.4, liquid volume 50 mL/250 mL, inoculum size 8%, temperature 30 ℃. Under this optimal conditions, epothilone B production reached up to 108.67 mg/L which is the highest yield of epothilone B on home and overseas and was 36.13% higher than preliminary conditions.
