Salinivibrio kushneri sp. nov., a moderately halophilic bacterium isolated from salterns

Abstract

Ten Gram-strain-negative, facultatively anaerobic, moderately halophilic bacterial strains, designated AL184^T, IB560, IB563, IC202, IC317, MA421, ML277, ML318, ML328A and ML331, were isolated from water ponds of five salterns located in Spain. The cells were motile, curved rods and oxidase and catalase positive. All of them grew optimally at 37°C, at pH 7.2-7.4 and in the presence of 7.5% (w/v) NaCl. Based on phylogenetic analyses of the 16S rRNA, the isolates were most closely related to Salinivibrio sharmensis BAG^T (99.6-98.2% 16S rRNA gene sequence similarity) and Salinivibrio costicola subsp. costicola ATCC 35508^T (99.0-98.1%). According to the MLSA analyses based on four (gyrB, recA, rpoA and rpoD) and eight (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA) concatenated gene sequences, the most closely relatives were S. siamensis JCM 14472^T (96.8-95.4% and 94.9-94.7%, respectively) and S. sharmensis DSM 18182^T (94.0-92.6% and 92.9-92.7%, respectively). In silico DNA-DNA hybridization (GGDC) and average nucleotide identity (ANI) showed values of 23.3-44.8% and 80.2-91.8%, respectively with the related species demonstrating that the ten isolates constituted a single novel species of the genus Salinivibrio. Its pangenome and core genome consist of 6041 and 1230 genes, respectively. The phylogeny based on the concatenated orthologous core genes revealed that the ten strains form a coherent phylogroup well separated from the rest of the species of the genus Salinivibrio. The major cellular fatty acids of strain AL184^T were C_16:0 and C_18:1. The DNA G+C content range was 51.9-52.5mol% (T_m) and 50.2-50.9mol% (genome). Based on the phylogenetic-phylogenomic, phenotypic and chemotaxonomic data, the ten isolates represent a novel species of the genus Salinivibrio, for which the name Salinivibrio kushneri sp. nov. is proposed. The type strain is AL184^T (=CECT 9177^T=LMG 29817^T).

Keywords: Genomic analysis; Moderately halophilic bacteria; New species; Salinivibrio; Salterns; Vibrionaceae.