Mangrovivirga cuniculi gen. Nov., sp. nov., a moderately halophilic bacterium isolated from bioturbated red sea mangrove sediment, and proposal of the novel family mangrovivirgaceae fam. nov.

Abstract

A strictly aerobic, Gram-stain-negative, non-motile, rod-shaped bacterium, designated strain R1DC9T, was isolated from sediments of a mangrove stand on the Red Sea coast of Saudi Arabia via diffusion chamber cultivation. Strain R1DC9T grew at 20–40 °C (optimum, 37 °C), pH 6–10 (optimum, pH 8) and 3–11% NaCl (optimum, 7–9%) in the cultivation medium. The genome of R1DC9T was 4661901 bp long and featured a G+C content of 63.1 mol%. Phylogenetic analyses based on the 16S rRNA gene sequence and whole-genome multilocus sequence analysis using 120 concatenated single-copy genes revealed that R1DC9T represents a distinct lineage in the order Cytophagales and the phylum Bacteroidetes separated from the Roseivirgaceae and Marivirgaceae families. R1DC9T displayed 90 and 89% 16S rRNA gene sequence identities with Marivirga sericea DSM 4125T and Roseivirga ehrenbergii KMM 6017T, respectively. The predominant quinone was MK7. The polar lipids were phosphatidylethan-olamine, two unknown phospholipids and two unknown lipids. The predominant cellular fatty acids were the saturated branch chain fatty acids iso-C15:0, iso-C17:0 3-OH and iso-C17:0, along with a low percentage of the monounsaturated fatty acid C16:1 ω5c. Based on differences in phenotypic, physiological and biochemical characteristics from known relatives, and the results of phylogenetic analyses, R1DC9T (=KCTC 72349T=JCM 33609T=NCCB 100698T) is proposed to represent a novel species in a new genus, and the name Mangrovivirga cuniculi gen. nov., sp. nov. is proposed. The distinct phylogenetic lineage among the families in the order Cytophagales indicates that R1DC9T represents a new family for which the name Mangrovivirgaceae fam. nov. is proposed.