Chemical analysis and biological activities of extracts from S. lavendulae wild-type and mutant strains. (A) HPLC analysis of authentic mitomycin C standard, mitomycin C production in the wild-type S. lavendulae, wild type with vector control, and mitA and mitB disruption mutants of S. lavendulae. For each analysis, 1 mg of crude extract was injected; 1 μg of MC was injected as a standard. (B) B. subtilis bioassay of MC production in mitA disruption mutant strain of S. lavendulae. Filter discs: 1, 100-μg injection of wild type (collected from 12.5 to 13.5 min); 2, 100-μg injection of mitA disruption mutant (collected from 12.5 to 13.5 min); 3, 100-μg injection of the wild type containing the vector (collected from 12.5 to 13.5 min); 4, 1 μg of MC collected from HPLC from 12.5 to 13.5 min; 5, Tris buffer negative control; 6) methanol solvent negative control.