Fig 6.

Assay of the blasticidin S production of the ΔblsL mutant strain S. lividans WJ3. (A) High-performance liquid chromatography comparison of the blasticidin S standard to the purified fermentation broth of WJ3, WJ2, and HXY16. LC-MS analysis revealed the peak presented in the fermentation broth of LL2 and WJ2, with a dominant peak at m/z 409. (B) MS/MS analysis of the m/z 409 parent ion. Each labeled daughter peak (corresponding structures are shown in the inset) could be derived from demethylblasticidin S. (C) PCR confirmation of the genotype of the ΔblsL mutant WJ3 with primer Con-blsL (see Table S2 in the supplemental material). M, DNA marker; WJ2, PCR product targeting blsL from S. lividans WJ2; WJ3, PCR product targeting blsL from S. lividans WJ3.