Catalyzes the anaerobic oxidation of oxalate using a broad range of electron acceptors, including ferredoxin and the nickel-dependent carbon monoxide dehydrogenase. Does not require coenzyme A as cosubstrate. Enables anaerobic growth on oxalate which is used as energy source by the bacteria. oxalate + oxidized 2[4Fe-4S]-[ferredoxin] = 2 CO2 + reduced 2[4Fe-4S]-[ferredoxin] Kinetic parameters determined with the heterodimer oxalate oxidoreductase complex. Optimum pH is 8.7. Dimer of heterotrimer of one alpha, one beta and one delta subunit.