Carbon substrate assimilation profiles and other taxonomic features of Alcaligenes faecalis, Alcaligenes ruhlandii and Achromobacter xylosoxidans.

Abstract

Twenty-eight strains of faecalis, one strain of ruhlandii, and 10 strains of Achromobacter xylosoxidans were characterized by assimilation of 103 carbon compounds, investigation of more than 70 conventional phenotypic characteristics and estimation of DNA base composition. faecalis was divided into two homogeneous clusters with DNA base compositions of 55.6-58.9mol% and 63.8-68.6mol%, respectively, characterized by assimilation of 35 substrates and 13 other phenotypic features. faecalis should be confined to the low GC cluster. The high GC cluster corresponded to Alcaligenes denitrificans, and could not be distinguished from ruhlandii and Achromobacter xylosoxidans except for the inability of the strains in the high GC cluster to assimilate carbohydrates. The strains in the low GC cluster were differentiated from other strains by the following attributes: fruity odor formation, greening of blood agar, presence of deaminases for phenylalanine and tryptophan, decomposition of xanthine, formation of dark-brown pigment from tryptophan and histidine, and assimilation of malonate, glycine and phenol, in contrast to the ability of the strains in the high GC cluster to reduce nitrate to nitrite and to assimilate mucate, adipate, pimelate, suberate, azelate, sebacate, meso-tartrate, itaconate, mesaconate, β-alanine, L-serine, DL-citrulline, and pantothenate. The low GC strains denitrified nitrite, whereas denitrification of nitrate and nitrite by the high GC strains fluctuated.