Draconibacterium aestuarii sp.nov., a Glycolipid-Producing Bacterium Isolated from Tidal Flat Sediment and Emended Description of the Genus Draconibacterium

Abstract

A facultatively anaerobic, Gram-negative, curved rod-shaped bacterium (4.0-17.0 μm long, 0.6-0.9 μm wide), designated Z1-6^T, was obtained from tidal flat sediment collected from YueAo village in Zhoushan, Zhejiang, People's Republic of China. Strain Z1-6^T occurred at 15-45 °C (optimum 28-32 °C), pH 6.0-9.0 (optimum 7.0-7.5), and in the presence of 1-5% (w/v) NaCl (optimum 1-2%). The strain contained iso-C_15:0 and antesio-C_15:0 as the major fatty acids. An unsaturated menaquinone with seven isoprene units (MK-7) was the predominant respiratory quinone. The polar lipids included phosphatidylethanolamine (PE), one aminophospholipid (APL), two phospholipids (PL1 and PL2), three glycolipids (GL1, GL2, and GL3), and two unidentified lipids (L1 and L2). The genomic DNA G+C content of strain Z1-6^T was 39.2%, and the genome size was 6.4 Mb. The strain showed the highest average nucleotide identity (ANI) value of 73.5-74.6%, digital DNA-DNA hybridization (dDDH) value of 19.3-20%, average amino acid identity (AAI) value of 72.0-73.1% with the members of genus Draconibacterium. Phylogenetic analysis based on 16S rRNA gene sequences and genome revealed that strain Z1-6^T formed a distinct branch in the clade of the genus Draconibacterium. Based on the phenotypic, phylogenetic, chemotaxonomic analyses and genomic data, strain Z1-6^T represents a novel species of the genus Draconibacterium, for which the name Draconibacterium aestuarii sp. nov. (The type strain Z1-6^T = MCCC 1K07533^T = KCTC 92310^T) is proposed.