Polaribacter sejongensis sp. nov., isolated from Antarctic soil, and emended descriptions of the genus Polaribacter, Polaribacter butkevichii and Polaribacter irgensii

Abstract

A Gram-staining-negative, catalase- and oxidase-positive bacterium, non-motile, designated strain KOPRI 21160T, was isolated from Antarctic soil. Based on 16S rRNA gene sequence analysis, strain KOPRI 21160T was found to belong to the genus Polaribacter. Sequence similarity between strain KOPRI 21160T and the type strains of Polaribacter species was 94.2？ 98.3%. The nearest phylogenetic neighbors of strain KOPRI 21160T were Polaribacter butkevichii KCTC 12100T (98.3%) and Polaribacter irgensii KCTC 23136T (97.5%). The DNA-DNA relatedness value between strain KOPRI 21160T and P. butkevichii KCTC 12100T was 50.6%, and 45.2% between strain KOPRI 21160T and P. irgensii KCTC 23136T. Strain KOPRI 21160T grew at 4？ 37°C and at pH 7.0？ 8.5. It could hydrolyze DNA, starch and Tweens 20, 40, 60 and 80. Menaquinone-6 (MK-6) was the only respiratory quinone, and iso-C15:0 (18.1%), iso-C15:0 3OH (17.9%) and C15:1 ω6c (10.4%) were the major cellular fatty acids. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and one unidentified lipid. The DNA G+C content was 30.0 mol%. Based on polyphasic data, the organism is considered as a novel species of the genus Polaribacter, for which we propose the name Polaribacter sejongensis sp. nov. The type strain is KOPRI 21160T (= KCTC 23670T = JCM 18092T). Emended descriptions of the genus Polaribacter, Polaribacter butkevichii Nedashkovskaya e Polaribacter. Sequence similarity between strain KOPRI 21160T and the type strains of Polaribacter species was 94.2？ 98.3%. The nearest phylogenetic neighbors of strain KOPRI 21160T were Polaribacter butkevichii KCTC 12100T (98.3%) and Polaribacter irgensii KCTC 23136T (97.5%). The DNA-DNA relatedness value between strain KOPRI 21160T and P. butkevichii KCTC 12100T was 50.6%, and 45.2% between strain KOPRI 21160T and P. irgensii KCTC 23136T. Strain KOPRI 21160T grew at 4？ 37°C and at pH 7.0？ 8.5. It could hydrolyze DNA, starch and Tweens 20, 40, 60 and 80. Menaquinone-6 (MK-6) was the only respiratory quinone, and iso-C15:0 (18.1%), iso-C15:0 3OH (17.9%) and C15:1 ω6c (10.4%) were the major cellular fatty acids. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and one unidentified lipid. The DNA G+C content was 30.0 mol%. Based on polyphasic data, the organism is considered as a novel species of the genus Polaribacter, for which we propose the name Polaribacter sejongensis sp. nov. The type strain is KOPRI 21160T (= KCTC 23670T = JCM 18092T). Emended descriptions of the genus Polaribacter, Polaribacter butkevichii Nedashkovskaya e