Mongoliitalea daihaiensis sp. nov., isolated from Daihai Lake in Inner Mongolia.

Abstract

A novel Gram-negative strain, designated X100-76T, was isolated from Daihai Lake in Inner Mongolia, Republic of China. The strain was non-motile, non-spore-forming, long-rod-shaped, oxidase positive and catalase positive. Colonies incubated at 33°C on 2216 marine agar medium for 3days were circular, smooth, transparent, convex with clear edges, orange-red in colour and approximately 1.0mm in diameter. Growth occurred at pH 6.5-12 (optimum pH 7.5), in 0-5.0% (w/v) NaCl (optimum 1.5%, w/v) and at 4-40°C (optimum 28-33°C). Phylogenetic analysis based on 16S rRNA gene sequences showed that X100-76T belongs to the genus Mongoliitalea and is most closely related to Mongoliitalea lutea MIM18T with 98.3% sequence similarity. The total genome size of X100-76T was 4,816,617bp with a G + C content of 39.6%. The digital DNA-DNA hybridization and average nucleotide identity values between strain X100-76T and M. lutea MIM18T were both below the recommended cut-off values. Chemotaxonomic analysis revealed iso-C15:0, Sum Feature 4 (anteiso-C17:1 B and/or iso-C17:1 I), C15:1ω6c, Sum Feature 9 (C16:0 10-methyl and/or iso-C17:1ω9c), C16:0 and iso-C15:1 G as the major fatty acids, menaquinone MK-7 as the major isoprenoid quinone, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol as the major cellular polar lipids. The results of polyphasic analysis demonstrated that X100-76T represents a novel species within the genus Mongoliitalea, for which the name Mongoliitalea daihaiensis sp. nov. is proposed. The type strain is X100-76T (= CGMCC 1.18762T = KCTC 82458T).