FIG. 5.

LC/MS analysis of culture supernatant of strain MSI011. The culture supernatant was prepared and analyzed by LC/MS as described in Materials and Methods. (A) Three-dimensional view of extracted ion chromatograms at different m/z values corresponding to possible LamD-derived peptide candidates. Twenty nanograms of nisin per milliliter was used for induction. Each m/z value used in the extracted ion chromatogram corresponds to a thiolactone peptide derived from the LamD fragment indicated in parentheses. (B) Three-dimensional view of extracted ion chromatograms at a m/z value of 559 (C25-W29) with increasing concentrations (conc.) of nisin added as indicated.