Chemotaxonomic and phenotypic characterization of the strains of species in the Flavobacterium-cytophaga complex.

Abstract

Quinone systems, DNA base composition, cellular fatty acid composition, and phenotypic characteristics of 41 strains of named Flavobacterium species, 10 strains of named Cytophaga species, and 16 isolates belonging to the Flavobacterium-Cytophaga complex were investigated. These strains were divided into two major groups on the basis of the quinone systems and DNA base composition: The ubiquinone system (Q-8 or Q-10) and high values in DNA base composition (64.1 to 69.2%) were found in one group. The strains in this group were divided into three clusters based on the cellular fatty acid composition and phenotypic characteristics. In this respect they were related to Pseudomonas or Alcaligenes species. The other group was characterized by the presence of the menaquinone system (MK-6 or MK-7), low values in DNA base composition (30.6 to 44.8%), and the presence of iso- and anteiso-acids in the cellular fatty acids. The strains of this group were separated into four clusters based on cellular fatty acid composition. All the named strains of Cytophaga species were included in this group. Cytophaga species were recognized by chemotaxonomic characteristics, and the accommodation of Flavobacterium aquatile strain Taylor F36 (=ATCC 11947=NCIB 8694), the type strain of the type species of the genus Flavobacterium, was discussed.