Rapid typing of Bacillus subtilis strains by their secondary metabolites using matrix-assisted laser desorption ionization mass spectrometry of intact cells

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spe ctrometry (TOFMS) has been used for rapid and efficient typing of Bacillus subtilis strains according to their secondary metabolite products using who le intact cells as targets. Cells were grown either in liquid media or on a gar plates, respectively, Strains were classified by their unique spectra o f bioactive peptides in the mit range from 500 to 5000, The lipopeptide pro ducts surfactin, fengycin and the members of the iturin family were structu rally characterized in situ by post-source decay (PSD) analysis. The potent ial of MALDI-MS for taxonomic studies, as well as for the investigation of the regulation and compartimentalization of secondary metabolites in the ba cterial cell, is demonstrated. These achievements qualify this methodology for rapid screening of microorganisms to exploit bioactive compounds for bi otechnological and pharmaceutical applications. Copyright (C) 1999 John Wil ey & Sons, Ltd.