The Metabolism of One-Carbon Compounds by Micro-Organisms

Abstract

One-carbon compounds occur abundantly at all oxidation levels between methane and carbon dioxide. Methane occurs in coal and oil deposits and is also evolved on a large scale as an end-product of many fermentations. Carbon dioxide is also abundantly present in the atmosphere, in natural waters, and as carbonates in the earth. A considerable number of micro-organisms have developed the ability to utilize such compounds as carbon or energy sources. This chapter examines these micro-organisms and the biochemical problems, which are posed by energy transduction and biosynthesis of cell constituents from the one-carbon substrate. It explains the description and physiology of one-carbon-utilizing micro-organisms along with their energy metabolism and carbon assimilation. The utilization of one-carbon compounds is largely confined to prokaryotic organisms. Many enzymes that catalyze the oxidation of one-carbon compounds at a variety of oxidation levels are also extensively studied. The chapter also considers mechanisms that offer a solution to the problem of net biosynthesis from one-carbon units at reduction levels ranging from carbon dioxide to methane.