Microbial H2/CO2 acetogenesis in animal guts: nature and nutritional significance.

The intestinal tract of invertebrate and vertebrate animals, including man, is an anoxic habitat wherein microbial formation of acetate from H2 + CO2 is often a major H2-consuming reaction. This paper will discuss the magnitude and microbiology of H2/CO2 acetogenesis in animal guts, its impact on host animal nutrition, competition for H2 between anaerobic microbes, and the global significance of intestinal H2/CO2 acetogenesis.