Oceanospirillum sediminis sp. nov., Isolated From Coastal Sediment in the Yellow Sea

Abstract

A novel Gram-negative, motile, aerobic, spiral-shaped bacterium designated D5^T, was isolated from a coastal sediment collected in the Yellow Sea. Optimal growth occurred at 30 °C, pH 7.0-8.0 and in the presence of 1-3% (w/v) NaCl. Strain D5^T contained ubiquinone 8 (Q-8) as the predominant respiratory quinone. The major fatty acids (> 10%) were C_16:0, C_16:1 ω7c/C_16:1 ω6c and C_18:1w7c/C_18:1w6c. The main polar lipids were phosphatidylglycerol and phosphatidylethanolamine. The draft genome is 5.6 Mb in length, and DNA G + C content is 47.2 mol%. 16S rRNA gene sequences showed that strain D5^T is most closely related to Oceanospirillum beijerinckii NBRC 15445^T (97.8%, sequence similarity). However, the digital DNA-DNA hybridization (dDDH) value and average nucleotide identity (ANI) between strain D5^T and O. beijerinckii is only 27.8% and 77.1%. Phylogenetic trees based on 16S rRNA gene sequences and whole genomes all indicated that strain D5^T formed a separate branch in the genus Oceanospirillum. Combined results of the polyphasic analyses suggested that strain D5^T represents a novel species in the genus Oceanospirillum, for which the name Oceanospirillum sediminis sp. nov. is proposed. The type strain is D5^T (= MCCC 1K06061^T = KCTC 62987^T).