Vibrio aquamarinus sp. nov., a luminous marine bacteria isolated from the Black Sea

Three novel bioluminescent bacterial strains, VNB-15 T , VNB-16 and SChm4, were isolated from water of the Black Sea (Russia) and intestines of the Black Sea horse mackerel. Cells of the isolated strains are motile Gram negative slightly curved rods with single polar flagellum. The temperature range for growth was 10-35°C, the optimum being 20-25°C. The pH range for growth was 6.0-9.0, the optimum being 7.0-8.0. The bacteria were able to grow in the presence of 0.5 to 5.0% NaCl (w/v), the optimum being 1.0-4.0% (w/v). Phylogenetic analysis based on comparison of 16S rRNA sequences shows these strains to have kinship with the species Vibrio jasicida, Vibrio hyugaensis, Vibrio alginolyticus, Vibrio campbelli, Vibrio rotiferianus, Vibrio harveyi and Vibrio owensii with sequence similarity from 99.6 to 98.0%. Phylogenetic analysis based on comparison of the sequences of genes gyrB , recA , pyrH , gapA, rpoA, mreB, ftsZ, topA shows that the strains VNB-15 T , VNB-16 and SChm4 to form a cluster within the V. harveyi clade and belong to a new species of the Vibrio genus. Comparison of the complete genomic sequence of VNB-15 T with typical strains of nearby species also indicates that VNB-15 T belongs to a separate species (maximum similarity 98% with V. hyugaensis and 96% with V. jasicida ). VNB-15 T differs from closely related species by its ability to utilize glucose, mannitol, inositol, sorbitol, rhamnose and sucrose, and to form lysine decarboxylase, ornithine decarboxylase, lipase, acid phosphatase, α-glucosidase, β-glucosidase and N-acetyl-β-D-glucosaminidase enzymes. Based on phylogenetic analysis and phenotypic characteristics, Vibrio aquamarinus sp. nov. is proposed. The type strain is VNB-15 T (= VKPM B-11245 T = DSM 26054 T ). Repositories The GenBank accession numbers for the gapA , 16S rRNA, gyrB , pyrH, rpoA, recA, mreB, ftsZ, topA genes sequences of strain VNB-15 T are JQ319116-JQ319121, KX242381, KX 242384, KX242387, respectively. The GenBank accession numbers for the gapA, gyrB , pyrH, recA, rpoA ,16S rRNA, mreB, ftsZ, topA genes sequences of strain VNB-16 are KP221561-KP221566, KX242382, KX 242385, KX242388 respectively. The GenBank accession numbers for the 16S rRNA, gapA gyrB, rpoA , recA, pyrH, mreB, ftsZ, topA genes sequences of strain SChm4 are KX242375-KX242380, KX242383, KX 242386, KX242389, respectively. The GenBank/EMBL/DDBJ accession numbers for the housekeeping gene sequences used in this study are detailed in supplementary Table S1, Figures S1-S8. The genome of Vibrio aquamarinus sp. nov. VNB-15 T , comprising two chromosomes and a plasmid, has been assembled and deposited in the NCBI database under the submission number SUB14585067