Sunxiuqinia indica sp. nov., isolated from deep sea.

Abstract

A Gram-stain-negative, facultative anaerobic, red-pigmented, rod-shaped and non-motile strain (RC1_OXG_1FT) was isolated from deep sea water of the Indian Ocean. It was able to grow at pH 5-8 (optimum, pH 7), at 5-37 °C (optimum, 30 °C), and at salinity (% NaCl, w/v) of 0.5-5 % (optimum, 1-2 %). Catalase- and oxidase-positive. It had highest 16S rRNA gene similarity (96.7 %) to 'Sunxiuqinia dokdonensis' DH1T, followed by Sunxiuqinia faeciviva JAM-BA0302T (96.6 %), Sunxiuqinia elliptica CGMCC 1.9156T (96.2 %), Sunxiuqinia rutila HG677T (96.0 %) and species (less than 92.3 %) of other genera. It belongs to the genus Sunxiuqinia within the phylum Bacteroidetes, based on the phylogenetic analysis. The results of digital DNA-DNA hybridization and average nucleotide identity analyses indicated that the strain belonged to a novel species. Its genome size is 5,250, 885 bp, with DNA G+C content of 40.5 mol%. Genome analysis revealed that the strain possessed many genes involved in polysaccharide degradation, especially hemicellulose degradation, indicating that the strain could maintain its normal metabolism by using recalcitrant organic matter in the oligotrophic deep sea environment. Its principal fatty acids were anteiso-C15 : 0 and iso-C15 : 0 and the major polar lipids were phosphatidylethanolamine, two unidentified glycolipids, three unidentified phospholipids and two unidentified polar lipids. The isoprenoid quinone was MK-7. Based on the phenotypic, chemotaxonomic and genotypic data, the strain represents a novel species within the genus Sunxiuqinia, for which the name Sunxiuqinia indica sp. nov. is proposed. The type strain is RC1_OXG_1FT (=MCCC 1A13858T=KCTC 62805T).