Curie-point Pyrolysis Mass Spectrometry Applied to Characterization and Identification of Selected Bacillus Species

1 Department of Microbiology, The Medical School, University Walk, University of Bristol, Bristol BS8 1TD, UK 2 Cadbury Schweppes PLC, Group Research, Lord Zuckerman Research Centre, University of Reading, Reading RG6 2LA, UK ABSTRACT SUMMARY: The use of pyrolysis mass spectrometry in the characterization and identification of Bacillus species was studied. Fifty-three strains of four closely related groups, Bacillus subtilis, B. pumilus, B. licheniformis and " B. amyloliquefaciens ", were used in a study of both sporulated and non-sporulated cultures. Pyrolysis was carried out using a Pyromass 8-80, a novel pyrolysis mass spectrometer specifically designed for fingerprinting complex samples. The pyrolysis data obtained were analysed using multivariate statistical techniques. All four groups could be differentiated using data from non-sporulated cultures but the data from sporulated cultures did not separate B. subtilis from " B. amyloliquefaciens " or B. pumilus. In contrast, B. licheniformis was more clearly differentiated from the other three species using these data. Culture maturity affected the mass spectra obtained from non-sporulated cultures.