LAUSR

The genus Prevotella plays an important role in polysaccharide degradation and fermentation in the rumen. To further understand the function of the phylogenetically diverse genus Prevotella, it is necessary to explore the individual characteristics at the species level. In this study, Gram-negative anaerobic bacterial strains isolated from the rumen of Holstein cows were identified. Strain R5019T was classified within the genus Prevotella based on 16S rRNA gene sequence-based phylogenetic analysis. The values of 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization between strain R5019T and its phylogenetically nearest species Prevotella multisaccharivorax PPPA20T were 89.8, 82.6, and 29.3 %, respectively. The genome size of R5019T was estimated to be ca. 4.19 Mb with a genomic G+C content of 49.5 mol%. The major cellular fatty acids and menaquinones were C15 : 0 anteiso and C17 : 0 anteiso and MK-11 and MK-12, respectively. Succinate, lactate, malate, acetate and formate were produced as the fermentation end products using glucose. Based on phylogenetic, physiological, biochemical and genomic differences between 11 strains and other phylogenetically related Prevotella species, a novel species, Prevotella lacticifex sp. nov., is proposed within the genus Prevotella. The type strain is R5019T (=JCM 34664T=DSM 112675T).