Leptobacterium flavescens gen. nov., sp nov., a marine member of the family Flavobacteriaceae, isolated from marine sponge and seawater

Six obligately aerobic, Gram-negative, non-motile, pale-yellow-pigmented, rod-shaped bacterial strains, designated YM3-301(T), HG868, 04PA2 Co4-8B, 04PA2 Co4-99A, 04PA2 018SW-3 and 04PA2 018SW-18, were isolated from a marine sponge and seawater and were subjected to a polyphasic taxonomic investigation. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the novel isolates were affiliated with the family Flavobacteriaceae (phylum Bacteroidetes) and that they showed the highest sequence similarity (90.3-90.9%) to members of the genus Leeuwenhoekiella and to Zhouia amylotica. The 16S rRNA gene sequence similarities with respect to members of other related genera were only 86.3-89.1%. In contrast, the six isolates shared high levels of 16S rRNA gene sequence similarity (99.7-100%) and DNA-DNA relatedness (72-94%) with each other. The novel isolates were phenotypically and physiologically different from members of related genera. The G + C content of the DNA was 41.8-43.5 mol%, MK-6 was the major menaquinone and i 15: 0, i 15: 1 and i 17: 0 3-OH were the major fatty acids. On the basis of the data from the taxonomic studies, it was concluded that these six novel strains represent a novel genus and species of the family Flavobacteriaceae, for which the name Leptobacterium flavescens gen. nov., sp. nov. is proposed. The type strain of Leptobacterium flavescens is YM3-301(T) (=KCTC 22160(T)= MBIC 06275(T) =NBRC 104141(T)).