Bacteroides graminisolvens sp. nov., a xylanolytic anaerobe isolated from a methanogenic reactor treating cattle waste.

A strictly anaerobic bacterial strain, designated XDT-1T, was isolated from plant residue from a methanogenic reactor treating waste from cattle farms. Cells of the strain were Gram-negative, non-motile, non-spore-forming rods. Haemin was required for growth. The strain utilized xylan as well as various sugars including arabinose, xylose, glucose, mannose, cellobiose, raffinose, starch and pectin. The strain produced acetate, propionate and succinate from saccharides in the presence of haemin. The optimum pH for growth was approximately 7.2 and the optimum growth temperature was 30-35 degrees C. The strain was sensitive to bile. The major cellular fatty acids of the strain were anteiso-C15:0 and iso-C17:0 3-OH, MK-10(H0) was the major respiratory quinone and the genomic DNA G+C content was 38.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed the strain in the phylum Bacteroidetes. The closest phylogenetic neighbour of strain XDT-1T was Bacteroides ovatus NCTC 11153T, with a 16S rRNA gene sequence similarity of 94.2%. On the basis of data from the phylogenetic, physiological and chemotaxonomic analyses, strain XDT-1T represents a novel species of the genus Bacteroides, for which the name Bacteroides graminisolvens sp. nov. is proposed. The type strain is XDT-1T (=JCM 15093T=DSM 19988T).