Romboutsia sedimentorum sp. nov., isolated from an alkaline-saline lake sediment and emended description of the genus Romboutsia

Abstract

A Gram-stain-positive, spore-forming, obligately anaerobic bacterium, designated LAM201T, was isolated from sediment samples from an alkaline-saline lake located in Daqing oilfield, Daqing City, PR China. Cells of strain LAM201T were non-motile and straight or spiral rod-shapes. Strain LAM201T was able to utilize glucose, fructose, maltose, trehalose and sorbitol as the sole carbon source. Acetic acid, ethanol, iso-butanoic acid and iso-valeric acid were the main products of glucose fermentation. The major fatty acids of LAM201T were C16 : 0 (26.7 %) and C18 : 0 (11.2 %). The main polar lipids were four unknown glycolipids and five unknown phospholipids. The predominant cell-wall sugars were ribose and galactose. The cell-wall peptidoglycan of strain LAM201T contained alanine, glycine, glutamic acid and aspartic acid. Sodium sulfite was used as the electron acceptor. The G+C content of the genomic DNA was 32±0.8 mol%, as determined by the T m method. Analysis of the 16S rRNA gene sequence indicated that the isolate belonged to the genus Romboutsia and was most closely related to Romboutsia lituseburensis DSM 797T and Romboutsia ilealis CRIBT with 97.3 % and 97.2 % similarities, respectively. The DNA–DNA hybridization values between strain LAM201T and the two reference strains were 37 % and 31 %, respectively. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM201T is suggested to represent a novel species within the genus Romboutsia , for which the name Romboutsia sedimentorum sp. nov. is proposed. The type strain is LAM201T ( = ACCC 00717T = JCM 19607T).