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 spp., 10 strains of named Cytophaga spp., and 16 isolates belonging to the Flavobacterium-Cytophaga complex were investigated. These strains were divided into 2 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 (64.1-69.2%) were found in 1 group. The strains in this group were divided into 3 clusters based on the cellular fatty acid composition and phenotypic characteristics. In this respect they were related to Pseudomonas or Alcaligenes spp. The other group was characterized by the presence of the menaquinone system (MK-6 or MK-7), low values in DNA base composition (30.6-44.8%) and the presence of iso- and anteiso-acids in the cellular fatty acids. The strains of this group were separated into 4 clusters based on cellular fatty acid composition. All the named strains of Cytophaga spp. were included in this group. Cytophaga spp. were recognized by chemotaxonomic characteristics and the accommodation of F. aquatile strain Taylor F36 (= ATCC 11947 = NCIB 8694), the type strain of the type species of Flavobacterium, was discussed.