Pseudohoeflea coraliihabitans sp. nov., a poly-β-hydroxybutyrate-producing, halotolerant bacterium isolated from coral sediment in the Dapeng peninsula (Guangdong, China)

Abstract

A Gram-stain-negative, strictly aerobic, motile, flagellated, rod-shaped, halotolerant, and poly-β-hydroxyalkanoate-producing bacterium, designated DP4N28-3T, was isolated from offshore sediment surrounding hard coral in the Dapeng peninsula (Guangdong, PR China). Growth occurred at 15–35 °C (optimal at 30 °C), pH 6.0–9.5 (optimal at 6.0–7.0), and 0.0–30.0 % NaCl concentration (w/v, optimal at 0.0–2.0 %), showing halotolerance. Phylogeny based on 16S rRNA gene sequences, five housekeeping genes, and genome sequences identified Pseudohoeflea suaedae DSM 23348T (98.1 %, 16S rRNA gene sequence similarity) as the most related species to strain DP4N28-3T. Average nucleotide identity, digital DNA–DNA hybridization, and average amino acid identity values between strain DP4N28-3T and P. suaedae DSM 23348T were all below the threshold of species demarcation. Major phenotypic differences were the flagella type and the limited sources of single carbon utilization by strain DP4N28-3T, which only included acetic acid, acetoacetic acid, d-glucuronic acid, and glucuronamide. Strain DP4N28-3T harboured the class I poly-β-hydroxyalkanoate synthase gene (phaC) and produced poly-β-hydroxybutyrate. The fatty acids were summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c, 49.4 %) and C16 : 0 (13.4 %). The major cellular polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, and sulfoquinovosyl diacylglycerol. The respiratory quinone was Q-10. The results of the phylogenetic, genomic, phenotypic, and chemotaxonomic analysis indicated that the isolated strain represents the type strain of a novel species. Based on these results, strain DP4N28-3T (=MCCC 1K05639T=KCTC 82803T) is proposed as the type strain of the novel species Pseudohoeflea coraliihabitans sp. nov.