Catalyzes the oxidation of C1-C3 aldehydes. Involved in peptides fermentation. an aldehyde + H2O + 2 oxidized [2Fe-2S]-[ferredoxin] = a carboxylate + 3 H(+) + 2 reduced [2Fe-2S]-[ferredoxin] Binds 1 [4Fe-4S] cluster per subunit. Binds 1 W-bis(molybdopterin guanine dinucleotide) (W-bis-MGD) cofactor per subunit. Inhibited by arsenite, iodoacetate and cyanide. Significant activity only with aliphatic aldehydes up to C3 and only at high concentration (15 mM). Optimum pH is above 10 (at 80 degrees Celsius). Optimum temperature is above 90 degrees Celsius (at pH 8.4). Homotetramer. A low amount of aldehyde ferredoxin oxidoreductase activity has been observed. Belongs to the AOR/FOR family.