Megasphaera stantonii sp nov., a butyrate-producing bacterium isolated from the cecum of a healthy chicken

A novel mesophilic, anaerobic, Gram-stain-negative bacterium was isolated from the cecum of a healthy white leghorn chicken, and designated AJH120(T). Cells were coccoid or diplococcoid with an average size of 0.8-1.8 mu m and were nonmotile with no evidence of spores. Phylogenetic analysis of 16S rRNA gene sequences revealed this organism to be a member of the genus Megasphaera, with the closest relatives being Megasphaera elsdenii (95% sequence identity) and Megasphaera cerevisiae (95% sequence identity). Growth was observed between 30 and 50 degrees C and between pH 5.0 and 9.0. AJH120(T) utilized a variety of carbon sources, including succinate, gluconate, fructose, ribose and pyruvate, as well as many individual amino acids. The DNA G+C content for the genome sequence of AJH120(T) was 52.1 mol%. Digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) between AJH120(T) and close taxonomic relatives, indicated divergence consistent with the strain representing a novel species. The major fatty acid methyl esters of the organism were C-12:0, C-14:0 3-OH, C-18:1 omega 9c, C-16:0 and C-16:1 omega 9c. AJH120(T) was able to produce several short chain fatty acids, including butyrate, acetate, propionate and isovalerate. Together, these data indicate that AJH120(T) represents a novel species within the genus Megasphaera. We propose the name Megasphaera stantonii sp. nov. for the species. The type strain of this species is AJH120(T) (= DSM 106750(T) = CCUG 71842(T)).