Fig. 1.

The biosynthetic gene cluster and productions of epothilones in S. cellulosum So0157-2 and So0157-2-esi ⁻. a A physical map of the epothilone gene cluster, showing the upstream esi gene SCE1572_25030, which was insertional inactivation (red arrow). The 17-bp sequence containing the four inverted repeat bases (in red) locates in the epothilone promoter. b Production of epothilones in So0157-2 and the esi ⁻ mutant in EMP medium. The error bars represent the standard deviation of three independent experiments. **P < 0.01