Identification of Bacillus spores by matrix-assisted laser desorption ionization-mass spectrometry

Unique patterns of biomarkers were reproducibly characterized by matrix-ass isted laser desorption ionization (MALDI)-mass spectrometry and were used t o distinguish Bacillus species members from one another. Discrimination at the strain level was demonstrated for Bacillus cereus spores. Lipophilic bi omarkers were invariant in Bacillus globigii spores produced in three diffe rent media and in B. globigii spores stored for more than 30 years. The sen sitivity was less than 5,000 cells deposited for analysis. Protein biomarke rs were also characterized by MALDI analysis by using spores treated briefl y with corona plasma discharge. Protein biomarkers were readily desorbed fo llowing this treatment. The effect of corona plasma discharge on the spores was examined.