- Purification and characterization of the tungsten enzyme aldehyde:ferredoxin oxidoreductase from the hyperthermophilic denitrifier Pyrobaculum aerophilum. Hagedoorn, P.L., Chen, T., Schröder, I., Piersma, S.R., de Vries, S., Hagen, W.R. J. Biol. Inorg. Chem. (2005)