Emendation of the Genus Cytophaga and Transfer of Cytophaga agarovorans and Cytophaga salmonicolor to Marinilabilia gen. nov.: Phylogenetic Analysis of the Flavobacterium-Cytophaga Complex

A 16S rRNA sequence analysis revealed that the genera Cytophaga, Flavobacterium, and Flexibacter are all polyphyletic and should be redefined and reorganized. Cytophaga hutchinsonii, the type species of the genus Cytophaga, belongs to a lineage that also contains Cytophaga aurantiaca. The genus Cytophaga is emended so that it contains only these two species, which decompose distinctly crystalline cellulose. Cytophaga salmonicolor and Cytophaga agarovorans form a lineage which is intermediate between other aerobic species and anaerobic bacteroides. Phenotypically, these organisms are characterized by being facultative anaerobes, inhabiting marine environments, and containing menaquinone-7 and spermidine. We propose that C. salmonicolor and C. agarovorans should be transferred to the genus Marinilabilia gen. nov. as Marinilabilia salmonicolor comb. nov. and Marinilabilia agarovorans comb. nov., respectively.