Sporosarcina hypophthalmichthys sp. nov. Isolated From Gastrointestinal Tract of Fish Hypophthalmichthys molitrix (Valenciennes, 1844).

Abstract

A rod-shaped, motile, Gram-stain-positive bacterial strain RKN2^T, was isolated from gut of silver carp (Hypophthalmichthys molitrix) residing in Gobindsagar reservoir, Himachal Pradesh, India. Having the greatest sequence similarity to Sporosarcina koreensis F73^T (98.51%), Sporosarcina luteola Y1^T (98.4%) and Sporosarcina aquimarina SW28^T (98.36%), the 16S rRNA gene phylogeny confirmed the belonging of strain RKN2^T to genus Sporosarcina. Digital DNA-DNA hybridization values were 21.7%, 20.6%, and 19.2%, and average nucleotide identity values were 76.42%, 80.16%, 76.51%, of strain RKN2^T with Sporosarcina koreensis F73^T, Sporosarcina luteola Y1^T, and Sporosarcina aquimarina SW28^T, respectively. The genomic analysis of strain RKN2^T showed various biological properties including nitrate reduction, genes responsible for carbohydrate-active enzymes production, antimicrobial compounds, as well as potential metabolism of aromatic compounds and heavy metals. G+C composition of RKN2^T genome was 52.7%. This strain can grow in temperatures between 10°C and 40°C (optimum, 28°C-30°C), NaCl concentrations up to 6.0% (w/v), and 6.0-8.0 (optimum, 6.5-7.5) pH range. MK-7 was the dominant respiratory quinone, A-4 type cell wall peptidoglycan was present with anteiso-C_15:0, iso-C_15: 0, and anteiso-C17:0 being the major fatty acids and Lys-Glu being main amino acids. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were the strain RKN2^T's three main polar lipids. The strain is a novel species under genus Sporosarcina based on polyphasic approach and the name Sporosarcina hypophthalmichthys sp. nov. is given for strain RKN2^T. RKN2^T is a type strain (= MCC 4365^T = JCM34522^T = CCM9112^T).