RAPID TYPING AND ELUCIDATION OF NEW SECONDARY METABOLITES OF INTACT CYANOBACTERIA USING MALDI-TOF MASS-SPECTROMETRY

Toxic cyanobacterial blooms are a threat because of secondary metaboli te production. We used matrix-assisted laser desorption/ionization tim e-of-flight mass spectrometry to identify intact microorganisms. Micro gram quantities of prepared cells, including solvent (acetonitrile and ethanol) and alpha-cyano-4-hydroxycinnamic acid matrix, display spect ra showing predominantly the secondary metabolites including known mic rocystins, micropeptin, and anabaenopeptolin. A new cyclic anabaenopep tolin has been identified using the Post-Source-Decay mode. Strains of various origins can easily be typed according to their cyclic peptide production, and toxic and nontoxic algal blooms can be differentiated within minutes.