Dongia sedimenti sp. nov., isolated from river sediment

A Gram-stain-negative, non-spore-forming and strictly aerobic bacterial strain, designated R-7^T, was isolated from river sediment in Wuxi, Jiangsu, PR China. Cells (1.6-3.8 µm long and 0.6-0.8 µm wide) were slightly curved to straight rods and motile by means of a polar flagellum. The strain grew optimally on Reasoner's 2A medium at 30 °C, pH 7.0 and with 1.0% (w/v) NaCl. Strain R-7^T exhibited closest 16S rRNA gene sequence similarities to <i>Dongia mobilis</i> CGMCC 1.7660^T (95.4%), <i>D. rigui</i> 04SU4-P^T (94.6%) and <i>D. soli</i> D78^T (93.8%). The phylogenetic trees based on genomic and 16S rRNA gene sequences showed that strain R-7^T was clustered in the genus <i>Dongia</i>. The obtained average nucleotide identity and digital DNA-DNA hybridization values between R-7^T and the three type strains of the genus <i>Dongia</i> were 73.4, 72.8 and 72.4% and 19.5, 19.0 and 18.7%, respectively. The major respiratory quinone was Q-10. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminolipids, two unidentified aminophospholipids and nine unidentified polar lipids. The major cellular fatty acids (>5% of the total) were cyclo-C_{19 : 0} <i> ω</i>8<i>c</i>, C_{16 : 0} and C_{16 : 0} 2-OH. The DNA G+C content was 65.5 mol%. On the basis of the evidence presented in this study, strain R-7^T represents a novel species of the genus <i>Dongia</i>, for which the name <i>Dongia sedimenti</i> sp. nov. is proposed, with strain R-7^T (=KCTC 8082^T=MCCC 1K08805^T) as the type strain.