Significance of Cellular Fatty Acids and Sugars in Defining the Genus Porphyromonas

Abstract

It has recently been proposed that three asaccharolytic species forming pigmented colonies on blood agar should be transferred from the genus Bacteroides to the new genus Porphyromonas. In the taxonomy of the genus Bacteroides cellular fatty acid profiles obtained by gas chromatography and mass spectrometry after methylation and derivatization of whole cells have proved to be useful. In this study cellular fatty acids and sugars were analyzed in strains of Porphyromonas and Bacteroides species, and the resulting multivariate data were investigated by using principal component analysis. This analysis clearly separated the Porphyromonas spp. strains from the strains of Bacteroides fragilis, Bacteroides melaninogenicus, Bacteroides intermedius, and Bacteroides levii. In the description of the genus Porphyromonas the presence of various hydroxylated fatty acids was not discussed. In this study we show that these cellular components are useful taxonomic markers.