PYROLYSIS MASS-SPECTROMETRY - DATA-PROCESSING IN CLASSIFICATION STUDIES

A scheme for numerical processing of pyrolysis mass spectrometry (Py-M S) data is detailed, along with methods for combining the results of c onventional phenotypic and PyMS taxonomic surveys. The importance of t his combined approach in polyphasic taxonomy is emphasised; it yields data on cell composition and the nutritional and physiological interac tions of strains with their environment. Large collections of strains can be surveyed rapidly and economically yielding presumptive classifi cations, which may then be confirmed with a few representative strains in more demanding, difficult and expensive approaches. An objective, non-arbitrary method of establishing suitable cut-off points to deline ate group structures in dendrograms is also described.