Aequorivita lutea sp. nov., a novel bacterium isolated from the estuarine sediment of the Pearl River in China, and transfer of Vitellibacter todarodis and Vitellibacter aquimaris to the genus Aequorivita as Aequorivita todarodis comb. nov. and Aequorivita aquimaris comb. nov.

Abstract

A Gram-negative, aerobic, rod-shaped, non-motile by gliding bacterium was isolated from the estuarine sediment of the Pearl River in PR China and designated as strain q18T. Colonies were circular, smooth and yellow on marine agar after 48 h cultivation. Salinity, temperature and pH for optimal growth were 5 % (NaCl), 30 °C and 7, respectively. The 16S rRNA gene sequence of the strain q18T showed the highest similarity of 97.3 % to the type strain of Aequorivita echinoideorum CC-CZW007T. 16S rRNA gene-based phylogenetic analysis indicated that strain q18T grouped into the genus Aequorivita in the family Flavobacteriaceae of the phylum Bacteroidetes , and was distinct from all known species in the genus. Menaquinone (MK-6) was the main respiratory quinone detected in strain q18T. The major fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipids of strain q18T mainly comprised phosphatidylethanolamine, two unidentified aminolipids, two unidentified phospholipids and one unidentified polar lipid. The G+C content of the genome was ~42.8 mol%. The draft genome size of strain q18T was 3.3 Mbp. The average nucleotide identity values were around 79.0 % between strain q18T and reference Aequorivita strains. Based on the polyphasic analysis, strain q18T was confirmed to represent a novel species of the genus Aequorivita , for which the name Aequorivita lutea sp. nov., is proposed. The type strain is q18T (=CICC 24821T=KCTC 72764 T). Further, based on the results of phylogenetic, chemotaxonomic and phenotypic analyses, two species previously classified into the genus Vitellibacter , Vitellibacter todarodis Kim et al. 2018 and Vitellibacter aquimaris Thevarajoo et al. 2016, are transferred to the genus Aequorivita as Aequorivita todarodis comb. nov. and Aequorivita aquimaris comb. nov. respectively.