Nioella aestuarii sp. nov., of the family Rhodobacteraceae, isolated from tidal flat.

A bacterium, designated strain MME-018, was isolated from a tidal flat of the Muui-do in the Republic of Korea and identified within the family Rhodobacteraceae. The 16S rRNA gene sequence of the isolate showed the highest similarity to that of Nioella sediminis JS7-11 (98.9 %), followed by Nioella nitratireducens SSW136 (97.1 %). In phylogenetic analyses, these taxa formed a clade at neighbour-joining, maximum-likelihood, and maximum-parsimony algorithms, in which it was separated from other genus belonging to the family Rhodobacteraceae. Ubiquinone-10 (Q-10) was the major respiratory quinone. Major polar lipids included phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two unidentified phospholipids, and an unidentified lipid. Major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) C16 : 0, cyclo C19 : 0ω8c, and 11-methyl C18 : 1ω7c. Genomic DNA G+C content was 61 mol%. Cells were Gram-stain negative, non-motile, aerobic, and rod-shaped. This strain grew in 1‒4 % (w/v) NaCl, at 4-40 °C and pH 6.0‒8.0, with optimal growth in 2 % (w/v) NaCl, at 25‒30 °C and pH 7.0. DNA-DNA hybridization values between strain MME-018 and Nioella sediminis KCTC 42144 and Nioella nitratireducens KCTC 32417 were 17±3 and 13±1 %, respectively. On the basis of polyphasic taxonomic analysis, strain MME-018 is proposed to represent a novel species of the genus Nioella, for which the name Nioellaaestuarii sp. nov. The type strain of Nioellaaestuarii is MME-018 (=KCCM 43135=JCM 30752).