Abstract

A marine bacterium, designated IMCC3175T, was isolated from a seawater sample collected off the Antarctic coast. The strain was Gram-negative, obligately aerobic, carotenoid pigment-containing, and rod-shaped bacterium that divided by binary fission. As determined by 16S rRNA gene sequence comparisons, the most closely related genera were Formosa (92.9~93.3%), Bizionia (91.6~93.2%), Gaetbulibacter (91.5~92.8%), Sediminibacter (92.7%), Yeosuana (92.6%), Subsaximicrobium (92.1~92.2%), and Gillisia (89.5~92.2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a monophyletic clade together with the genera Sediminibacter and Subsaximicrobium but represented an independent phyletic line in this clade of the family Flavobacteriaceae. The DNA G+C content of the strain was 37.3 mol%. The major respiratory quinone was MK-6 and the predominant cellular fatty acids were C16:1 ω7c and/or iso-C15:0 2-OH (12.8%), anteiso-C15:0 (9.4%), and iso-C16:1 (9.4%). Low 16S rRNA gene sequence similarity, formation of a distinct phylogenetic branch, and several phenotypic characteristics, including a narrow range of temperature and salinity for growth, differentiated strain IMCC3175T from other related genera in the family Flavobacteriaceae. Therefore the name Antarcticimonas flava gen. nov., sp. nov. is proposed, with strain IMCC3175T (=KCCM 42713T =NBRC 103398T) as the type strain.

• Keywords: Antarcticimonas flava gen. nov.; sp. nov.; Flavobacteriaceae; Antarctic; seawater; phylogenetic analysis