Actinomyces ruminicola sp. nov., isolated from cattle rumen

Abstract

Two obligate anaerobic bacterial strains, B71Tand D471, were isolated from cattle rumen. The novel strains were Gram-positive and rod-shaped. The strains hydrolysed xylan and starch, fermented some mono-, di- and oligosaccharides and produced formic, acetic and lactic acids as end products from glucose. Growth of the isolates was observed at 20–55 °C and pH 6.5–9.0. The DNA G+C contents of strains B71Tand D471 were 68.06 and 68.26 mol%, respectively. Although the two novel strains met the genus description forActinomyces, some phenotypic characteristics, such as optimum growth temperature, requirement for O2and the end products of fermentation, distinguished them from previously described members of the genus. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the novel strains belonged to the genusActinomyces(88.3–93.6 % sequence similarity) and formed a distinct line within the clade containingActinomyces bovis. On the basis of these results, a novel species,Actinomyces ruminicolasp. nov., is proposed. The type strain is B71T(=JCM 13352T=CGMCC 1.5030T).