 These reducing equivalents then go on to produce adenosine triphosphate in the cel through the electron transport chain.Most industrial plants for biooxidation of gold-bearing concentrates have been operated at 40 °C with mixed cultures of mesophilic bacteria of the genera "Acidithiobacillus" or "Leptospirillum ferrooxidans".In other studies the iron-reducing archaea "Pyrococcus furiosus" were shown to produce hydrogen gas which can then be used as fuel.