Flavobacterium marinum sp. nov., isolated from seawater

A Gram-staining-negative, strictly aerobic, non-gliding, rod-shaped bacterial strain, designated SW105(T), was isolated from a seawater sample collected from the Indian Ocean. The strain produced flexirubin-type pigments and grew at 15-45 °C (optimum, 35 °C), at pH 5.5-8.5 (optimum, pH 7.0-7.5) and in the presence of 0-5.0 % (w/v) NaCl (optimum, 1.0-1.5 %). The predominant cellular fatty acids were iso-C15 : 0, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 1ω9c and iso-C17 : 0 3-OH. The major menaquinone was menaquinone 6 (MK-6) and the major polar lipids were phosphatidylethanolamine and two unidentified aminophospholipids. The genomic DNA G+C content of strain SW105(T) was 36.2 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the novel isolate was related to members of the genus Flavobacterium, showing the highest similarity to Flavobacterium ummariense DS-12(T) and Flavobacterium ceti CCUG 52969(T) (94.3 and 93.0 % sequence similarity, respectively). On the basis of phylogenetic inference and phenotypic characteristics, it is proposed that strain SW105(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium marinum sp. nov. is proposed. The type strain is SW105(T) ( = CGMCC 1.10825(T) = JCM 18132(T)).