Halomonas aestuarii sp. nov., a moderately halophilic bacterium isolated from a tidal flat

Abstract

Strain Hb3^T was isolated from a tidal flat in Jeollabuk-do Gunsan, Republic of Korea. Cells were Gram-stain-negative, oxidase- and catalase-positive, rod-shaped and motile. The strain grew optimally at 25-35 °C, at pH 6.0-6.5 and with 3.0-10.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Hb3^T belonged to the genus Halomonas. Strain Hb3^T was related most closely to Halomonas ventosae Al12^T (98.6 % 16S rRNA gene sequence similarity), Halomonas denitrificans M29^T (98.6 %) and Halomonas saccharevitans AJ275^T (98.4 %). Moreover, multilocus sequence analysis using the gyrB, rpoD and secA genes supported the phylogenetic position of strain Hb3^T. The genomic G+C content of strain Hb3^T was 67.9 mol%. DNA-DNA hybridization values for strain Hb3^T versus H. ventosae Al12^T, H. denitrificans M29^T and H. saccharevitans AJ275^T were 38.0, 54.5 and 47.4 %, respectively. The major quinone was ubiquinone Q-9 and the major fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and C19 : 0 cyclo ω8c. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, amino lipid, six unidentified phospholipids and an unidentified lipid comprised the polar lipid profile. On the basis of the data presented in this report, strain Hb3^T represents a novel species of the genus Halomonas. The name Halomonas aestuarii sp. nov. is proposed for this novel species. The type strain is Hb3^T (=KCTC 52253^T=JCM 31415^T).