Spongiibacterium pacificum sp. nov., isolated from seawater of South Pacific Gyre and emended description of the genus Spongiibacterium.

Abstract

A Gram-stain-negative, strictly aerobic, non-flagellated, non-gliding, oxidase-positive and yellow-pigmented rod-shaped bacterium, designated strain SW169(T), was isolated from a surface seawater sample collected from the South Pacific Gyre (27° 55' S 123° 10' W) during the Integrated Ocean Drilling Program (IODP) Expedition 329. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SW169(T) belonged to the genus Spongiibacterium and showed the highest 16S rRNA gene sequence similarity with Spongiibacterium flavum A11(T) (95.9 %). It showed 16S rRNA gene sequence similarities of 93.2-94.8 % with members of the genera Croceitalea and Flagellimonas in the family Flavobacteriaceae. Optimal growth occurred in the presence of 3-4 % (w/v) NaCl, at pH 8.0 and at 28 °C. The DNA G+C content of strain SW169(T) was 43.3 mol%. The major fatty acids were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c,). The major respiratory quinone was menaquinone-6. The major polar lipids were phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. On the basis of the polyphasic analyses, strain SW169(T) is considered to represent a novel species of the genus Spongiibacterium, for which the name Spongiibacterium pacificum sp. nov. is proposed. The type strain is SW169(T) ( = JCM 18379(T) = LMG 26997(T)). An emended description of the genus Spongiibacterium is also provided.