Bacteroides paurosaccharolyticus sp. nov., isolated from a methanogenic reactor treating waste from cattle farms

Abstract

A strictly anaerobic bacterial strain (WK042T) was isolated from rice-straw residue in a methanogenic reactor treating waste from cattle farms in Japan. Cells were Gram-staining-negative, non-motile, non-spore-forming rods. Growth was stimulated well by haemin, and was enhanced by cobalamin (vitamin B12). Strain WK042Tutilized arabinose, xylose, glucose, mannose and aesculin as preferred substrates. Maltose, dextrin, glycogen, starch and pectin were also utilized, although growth on these substrates was much slower. The strain produced acetate, propionate and succinate from these saccharides. The strain was slightly alkaliphilic, with optimum growth at pH 7.7. The temperature range for growth was 10–40 °C, the optimum being 35 °C. The strain was sensitive to bile. The major cellular fatty acids were anteiso-C15 : 0, iso-C17 : 03-OH and C15 : 0. Menaquinone 11 (MK-11) was the major respiratory quinone and the genomic DNA G+C content was 41.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed the strain in the phylumBacteroidetes. Strain WK042Twas related distantly to the type strains of species in the cluster includingBacteroides massiliensis,Bacteroides vulgatusandBacteroides dorei(91–92 % 16S rRNA gene sequence similarity). Based on data from the present phylogenetic, physiological and chemotaxonomic analyses, strain WK042Tis considered to represent a novel species of the genusBacteroides, for which the nameBacteroides paurosaccharolyticussp. nov. is proposed. The type strain is WK042T(=JCM 15092T=DSM 21004T).