Oxalate oxidase （Enzyme Commission number EC 1.2.3.4[2]）occurs mainly in plants. It can degrade oxalic acid into carbon dioxide and hydrogen peroxide.[3]
Oxalate decarboxylase (OXDC，EC 4.1.1.2) is a kind of oxalate degrading enzyme containing Mn2+,[4] found mainly in fungi or some bacteria. Brown rot fungi secrete oxalate to break down cellulose fibers of wood, but deploy this enzyme to permit regulatory control over the total quantity of oxalate present.[5] It can appear in the absence of other cofactors under the action of the degradation of oxalic acid directly to form formic acid and CO2.
Oxalyl-CoA decarboxylase（EC 4.1.1.8）mainly mediates degradation of bacterial oxalic acid.
Formyl-CoA transferase （EC 2.8.3.16）mediates the exchange of oxalyl and formyl groups on coenzyme A, interconverting formyl-CoA and oxalyl-CoA.
