Adenosinetriphosphate formation in the oxidation of succinic acid by bacteria.

In a previous paper (1) evidence was given to show that inorganic phosphate is esterified when succinate is incubated aerobically with cell-free extracts of Escherichia coli in the presence of inorganic phosphate. Based upon residual succinate determinations and upon the theoretical oxygen uptake for oxidation to fumarate, the data have been interpreted to mean that phosphorylation of inorganic phosphate occurs as a result of the single step oxidation from succinate to fumarate. However, no attempt was made to determine the actual end-products of the reaction. The compound containing the acid-labile phosphate was not identified. By the use of inorganic P32, carrier adenosinetriphosphate (ATP), and paper chromatography, it has been possible to show that the compound containing the acid-labile phosphate has the same Rp as known adenosinetriphosphate, and, by determining the end-products of succinic acid oxidation, it has been possible to confirm that a one-step oxidation is involved.