Zeaxanthinibacter aestuarii sp. nov., isolated from estuary sediment and emended description of the genus Zeaxanthinibacter Asker et al. 2007.

A Gram-staining-negative, strictly aerobic and yellow-pigmented bacterium, designated strain S2-22T, was isolated from estuary sediment in South Korea. Cells of strain S2-22T were oxidase- and catalase-positive rods without gliding motility. Growth was observed at 15-43 °C (optimum, 35-37 °C), at pH 5.5-9.0 (optimum, pH 6.5-7.5) and in the presence of 0.0-10.0 % (w/v) NaCl (optimum, 2.0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S2-22T formed a tight phyletic lineage with Zeaxanthinibacter enoshimensis TD-ZE3T with a high bootstrap value and their 16S rRNA gene sequence similarity was 94.6 %. The respiratory quinone detected was menaquinone 6 (MK-6) only and iso-C15 : 0, iso-C17 : 0 3-OH, summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c) and iso-C15 : 1G were the major fatty acids. Phosphatidylethanolamine was identified as the major polar lipid and five unidentified aminolipids, two unidentified phospholipids and three unidentified lipids were also detected as minor polar lipids. The G+C content of the genomic DNA was 45.5 mol%. Based on the phenotypic, chemotaxonomic and molecular features, strain S2-22T clearly represents a novel species of the genus Zeaxanthinibacter, for which the name Zeaxanthinibacter aestuarii sp. nov. is proposed. The type strain is S2-22T (=KACC 18503T=JCM 31155T). An emended description of the genus Zeaxanthinibacter is also proposed.