Oceanobacter mangrovi Sp. Nov., a Novel Poly-β-hydroxybutyrate Accumulating Bacterium Isolated from Mangrove Sediment.

Abstract

A Gram-stain-negative, rod-shaped, motile, mesophilic, and aerobic bacterial strain, designated SM2-42T was isolated from a mangrove sediment. Catalase activity and oxidase activity were positive. Growth was observed at 20°C-40°C, pH 6.0-8.0, and in the presence of 0.5-5.0% NaCl. Cells of strain SM2-42T contained poly-β-hydroxybutyrate granules. The 16S rRNA gene of strain SM2-42T had maximum sequence similarity with Oceanobacter kriegii 197T of 97.1%. Phylogenetic analysis based on 16S rRNA gene sequence and 120 conserved concatenated proteins indicated that strain SM2-42T was affiliated to the genus Oceanobacter and formed a monophyletic branch with O. kriegii 197T. The average nucleotide identity and digital DNA-DNA hybridization values between strain SM2-42T and O. kriegii 197T were 76.43% and 21.60%, respectively. The major isoprenoid quinone was Q-8. The major fatty acids (> 10%) comprised C16:0, summed feature 8 (C18:1ω7c and C18:1 ω6c), C18:0, and summed feature 3 (C16:1ω7c and/or C16:1 ω6c). The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and two unidentified lipids. The draft genome size was 5,115,008bp with DNA G + C content of 54.3%. Based on phylogenetic analyses and whole genomic comparisons, strain SM2-42T represented a novel species, for which the name Oceanobacter mangrovi sp. nov. was proposed. The type strain was SM2-42T (= MCCC 1K06300T = KCTC 82938T).