Enzymatic decarboxylation of oxalic acid.

Large quantities of oxalic acid accumulate in the cell sap of various plants and as a major product of carbohydrate metabolism by many molds. A recent investigation in our laboratory revealed that oxalic acid was produced from oxalacetic acid by an enzyme system which was isolated from the mycelia of Aspergillus niger (1). It was also demonstrated that oxalic acid was converted to formic acid and CO2 by an enzyme isolated from a soil bacterium (2). The latter reaction proceeded anaerobically and required ATP,l CoA, Mg++, ThPP, and acetate. The present communication is concerned with the purification and properties of an enzyme which is obtained from the mycelia of a wood-destroying fungus, Collyvia veltipes. This enzyme catalyzes the decarboxylation of oxalic acid with the formation of stoichiometric quantities of formic acid and carbon dioxide as follows: