A new bacterial strain, designated as FF42(T), was isolated from feces of domestic pigs-collected from Suwon, Korea-and was characterized to determine its taxonomic position. Strain FF42(T) was observed to be Gram negative, aerobic, non-spore forming, motile, and rod-shaped cells. Based on the phylogenetic and 16S rRNA sequence analyses, it was revealed that strain FF42(T) belonged to the genus Comamonas. The highest degree of sequence similarities was determined to be with Comamonas zonglianii BF-3(T) (96.3 %), Comamonas composti CC-YY287(T) (96.1 %), and Comamonas nitrativorans 23310(T) (95.9 %), while showing less than 95.6 % identity with the remaining Comamonas species. Growth of strain FF42(T) occurred between 25 and 40 A degrees C (optimum, 28 A degrees C) and at pH of 5-9 (optimum, pH 6.0). It grew in the presence of 0-3 % (w/v) NaCl while minimally tolerating at 3 % (w/v) NaCl. Biochemical and physiological tests revealed phenotypic differentiation of strain FF42(T) to other members of the genus Comamonas. The predominant quinone is ubiquinone (Q-8). The major cellular fatty acids were C-10:0 3OH, C-16:0, summed feature 3 (C-16:1 omega 7c/C-16:1 omega 6c), and summed feature 8 (C-18:1 omega 6c/C-18:1 omega 7c), all of which have previously been reported to occur in the species of the genus Comamonas. The G+C molar content for strain FF42(T) is 60.2 mol %. Based on phylogenetic and phenotypic analyses, strain FF42(T) (=KEMC 1002-058(T)=JCM 17561(T)) is clearly referred to be a novel species for the genus Comamonas, for which the name Comamonas faecalis sp. nov. is proposed.