Aestuariibaculum lutulentum sp. nov., a marine bacterium isolated from coastal sediment in Beihai.

A Gram-stain negative, strictly aerobic, and rod-shaped bacterium, designated as strain L182T, was isolated from coastal sediment in Beihai, Guangxi Province, PR China. Colonies of strain L182T were yellow, 2 mm in diameter, round, opaque, smooth and convex after incubation on marine ager at 30 °C for 3 days. Cells were catalase-positive but oxidase-negative. Growth of strain L182T was observed at 4-40 °C (optimum, 25 °C), pH 5.5-10.0 (optimum, pH 5.5-8.0) and with 0-6% (w/v) NaCl (optimum, 0.5-4.0%). The G + C content based on the genome sequence was 36.0%. The only respiratory quinone was MK-6. The main polar lipids included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, one unidentified glycolipids, four unidentified aminolipids and six unidentified lipids. The major fatty acids (> 10%) were iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The 16S rRNA gene sequence similarity between strain L182T and Aestuariibaculum suncheonense SC17T was 98.2%, and the similarities with other type strains of the genus Aestuariibaculum were 96.1-97.2%. The average nucleotide identity and in silicon DNA-DNA hybridization values between the strain L182T and its closely related Aestuariibaculum species were 80.8-85.2% and 22.0-29.5%. According to the above results, Aestuariibaculum lutulentum sp. nov. was proposed as a novel species. The type strain is L182T (= MCCC 1K08065T = KCTC 92530T).