Candidatus Enterousia, Bacteria with Reduced Genomes from the Intestines of Farm Animals.

As a result of metagenomic analysis of feces of farm animals, 5 genomes of alpha-proteobacteria of the candidate genus Enterousia of the order Rs-D84 were assembled. The genomes ranged in size from 850 to 984 kb and contained from 835 to 961 protein-coding genes. Analysis of the genomes showed that these bacteria have fermentative metabolism and could produce lactate and acetate. Most of the genes for the Embden−Meyerhof glycolytic pathway and the non-oxidative phase of the pentose phosphate pathway are present, but the genes for glucokinase, glucose-6-phosphate isomerase and transaldolase were not found. Enterousia lack aerobic and anaerobic respiratory pathways, complete pathways for the amino acid, lipid and nucleotide biosynthesis, as well as secreted glycoside hydrolases and conventional transporters for the import of sugars and amino acids. Enterousia appear to have adopted the lifestyle of a symbiont/parasite or a scavenger obtaining metabolites from other cells or lysed biomass. Comparative genome analysis revealed that genome reduction is a common trait of the vast majority of other members of the candidate order Rs-D84. [ABSTRACT FROM AUTHOR]