Acuticoccus mangrovi sp. nov., with an antibacterial property, isolated from mangrove sediment

A Gram-stain-negative, aerobic, milky white bacterium, designated B2012(T), was isolated from mangrove sediment collected at Beibu Gulf, South China Sea. Antimicrobial activity assay revealed that the isolate possesses the capability of producing antibacterial compounds. Strain B2012(T) shared the highest 16S rRNA gene sequence relatedness (96.9-95.5 %) with members of the genus Acuticoccus. The isolate and all known Acuticoccus species contain Q-10 as the main respiratory quinone and have the same polar lipid components (phosphatidylcholine, unidentified glycolipid, unidentified lipid, unidentified amino lipid and phosphatidylglycerol). However, genomic relatedness referred by values of average nucleotide identity, digital DNA-DNA hybridization, average amino acid identity and the percentage of conserved proteins between strain B2012(T) and other type strains of the genus Acuticoccus were below the proposed thresholds for species discrimination. The genome of strain B2012(T) was assembled into 65 scaffolds with an N50 size of 244239 bp, resulting in a 5.5 Mb genome size. Eight secondary metabolite biosynthetic gene clusters were detected in this genome, including three non-ribosomal peptide biosynthetic loci encoding yet unknown natural products. Strain B2012(T) displayed moderately halophilic and alkaliphilic properties, growing optimally at 2-3% (w/v) NaCl concentration and at pH 8-9. The major cellular fatty acids (>10%) were anteiso-C-15:0, C-16:0 dimethyl aldehyde (DMA) and C-16:0. Combined data from phenotypic, genotypic and chemotaxonomic analyses suggested that strain B2012(T) represents a novel species of the genus Acuticoccus, for which the name Acuticoccus mangrovi sp. nov. is proposed. The type strain of the type species is B2012(T) (=MCCC 1K04418(T)=KCTC 72962(T)).