THE CYTOPHAGA-LIKE BACTERIA: A SEARCH FOR KEY CHARACTERS

Abstract

Nearly 800 Cytophaga-like bacteria (CLB) were isolated from soil and freshwater. Mainly out of these isolates, 185 strains were chosen for a phenotypic analysis, employing 130 different tests. The aim was to find specific traits that would lead to a reasonable clustering and thus could be used as taxonomical key characters. An apparently reasonable classification was obtained with the following characters: gliding motility,cell morphology, cellular shape-change, presence of flexirubin-type pigments and of certain enzymes (catalase, cytochrome oxidase, lecithinase, urease, phenylalanine deaminase, DNase, starch hydrolysis, and gelatin liquefaction). The characters were weighted and used in the order given above. Obviously, this chosen hierarchy has an influence on the resulting arrangement of the strains. Nonetheless, it was possible to define certain groups quite reliably, such as Flexibacter and Lysobacter. However with other groups, particularly with subgroups, results were often ambiguous. A comparison with data obtained by DNA/DNA hybridization /4/ suggests, that for the different groups and subgroups of CLB different sets of key characters have to be applied, or that at least the hierarchy of the characters has to be altered.