Georgenia wangjunii sp. nov. and Georgenia sunbinii sp. nov. isolated from the faeces of Cygnus atratus in the Qinghai-Tibet Plateau of China.

Abstract

Four novel, Gram-stain-positive, catalase-positive, oxidase-negative, aerobic and non-motile strains, designated MJ206^T, MJ278, MJ170^T and MJ173, were isolated from the faeces of Cygnus atratus in the Qinghai-Tibet Plateau of China. A comparative analysis of 16S rRNA gene sequences revealed that strain pairs MJ206^T and MJ278, as well as MJ170^T and MJ173, belong to the genus Georgenia. Strain pair MJ206^T/MJ278 is most closely related to 'Georgenia faecalis' ZLJ0423 (98.19% 16S rRNA gene sequence similarity), while the strain pair MJ170^T/MJ173 is most related to Georgenia satyanarayanai JC82^T (98.00% 16S rRNA gene sequence similarity). These relationships were further confirmed by phylogenetic analyses based on the 16S rRNA gene and genome sequences. The two type strains (MJ206^T and MJ170^T) have low digital DNA-DNA hybridization values (20.3-23.9%) and average nt identity values (75.3-80.9%) with all available genomes in the genus Georgenia. The DNA G+C contents of strains MJ206^T and MJ170^T were 73.5 and 72.0 mol%, respectively. The predominant cellular fatty acids of both strains (MJ206^T and MJ170^T) were anteiso-C_15 : 0 and anteiso-C_{15:1 A}, but strain MJ206^T has an additional major fatty acid, which is anteiso-C_16 : 0. MK-8 (H₄) was the major menaquinone. The major polar lipids detected in strains MJ206^T and MJ170^T included diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The cell wall aa detected in the two novel species were alanine (Ala), glutamic acid (Glu), glycine (Gly), aspartic acid (Asp) and ornithine acid (Orn); the shared whole cell wall sugars consisted of ribose (Rib), glucose (Glu) and galactose (Gal). All genotypic and phenotypic data indicated that these four strains represented two novel species in the genus Georgenia, for which the names Georgenia wangjunii sp. nov. and Georgenia sunbinii sp. nov. are proposed, respectively. The type strains are MJ206^T (=CGMCC 1.4699^T=JCM 37421^T) and MJ170^T (=CGMCC 1.4698^T=JCM 37420^T).