Numerical Classification of Bacteria

Forty five organisms selected from 12 genera of bacteria listed in Bergey’s Manual (1957) were subjected to numerical analysis based on the two different similarity matrices representing the overall similarities of phenetic characters and the similarities of guanine + cytosine contents of DNA molecules.

The classification based on the similarities of GC-contents obtained “lump” taxa, in contrast with the classification based on the overall similarities of phenetic characters.

Rationale of the former classification is briefly discussed.