Paraneptunicella aestuarii gen. nov., sp. nov., a member of the family Alteromonadaceae isolated from seawater in East China Sea

Abstract

An aerobic Gram-stain-negative, curved rod-shaped and non-spore-forming bacterial strain (NBU2194T) was isolated from seawater collected in an intertidal zone in Ningbo, Zhejiang Province, PR China. It was motile though a single polar flagellum and grew at 20–42 °C (optimum, 30 °C), in 0–2.0 % NaCl (0 %, w/v) and at pH 5.0–9.0 (pH 6.0–7.0). The sole respiratory quinone was ubiquinone-8. The major cellular fatty acids were C16 : 0, C16 : 1  ω7c and/or C16 : 1  ω6c. The polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid and two unidentified aminophosphoglycolipids. A phylogenetic analysis based on 16S rRNA gene sequences and 65 genomic core genes showed that strain NBU2194T formed a distinct lineage in the family Alteromonadaceae . The genome of strain NBU2194T was 4 913 533 bp with a DNA G+C content of 43.9 mol% and coded 3895 genes, 12 rRNA genes and 47 tRNA genes. The average nucleotide identity, amino acid identity and digital DNA–DNA hybridization values between strain NBU2194T and related species of Alteromonadaceae were below the threshold limit for prokaryotic species delineation. NBU2194T could be distinguished from other genera in the family Alteromonadaceae based on phenotypic, chemotaxonomic and genomic characteristics. On the basis of the polyphasic taxonomic evidence collected in this study, strain NBU2194T is considered to represent a novel genus and species in the family Alteromonadaceae , for which the name Paraneptunicella aestuarii is proposed. The type strain is NBU2194T (=KCTC 82442T=GDMCC 1.2217T).