Marinifilum fragile gen. nov., sp. nov., isolated from tidal flat sediment.

A facultatively anaerobic, moderately halophilic, Gram-negative, filamentous bacterium, designated JC2469T, was isolated from tidal flat sediment in Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the phylum Bacteroidetes and its closest taxonomic relative was Cytophaga fermentans NCIMB 2218T (89.6% sequence similarity). Cells appeared as filaments during exponential growth, but became fragmented to rods at stationary phase. Spherical cells were also observed in aged cultures. Strain JC2469T contained iso-C15:0 (56.2%) and MK-7 as the predominant fatty acid and respiratory quinone, respectively. On the basis of evidence from this polyphasic study, the isolate showed substantial differences from other genera. The phylogenetic and physiological data of the present study strongly suggest that the isolate represents a novel genus and species, for which the name Marinifilum fragile gen. nov., sp. nov. is proposed. The type strain of Marinifilum fragile is JC2469T (=IMSNU 14138T=KCTC 22488T=JCM 15579T).