Improvement of epothilone B production by in situ removal of ammonium using cation exchange resin in Sorangium cellulosum culture

A cation exchange resin was added at different stages in the growth of Sorangium cellulosum cultures to remove excess ammonium, which has a negative influence on the production of the anticancer agent, epothilone. When 8 g L−1 of cation exchange resin were added at the mid-death phase, the ammonium removal reached 83% and the maximum production of epothilone was 14.3 mg L−1, which was 2.6 times greater than that of the control culture.