We propose a physically-realisable biochemical device that is coupled to a
biochemical reservoir of mutual information, fuel molecules and a chemical
bath. Mutual information allows work to be done on the bath even when the fuel
molecules appear to be in equilibrium; alternatively, mutual information can be
created by driving from the fuel or the bath. The system exhibits diverse
behaviour, including a regime in which the information, despite increasing
during the reaction, enhances the extracted work. We further demonstrate that a
modified device can function without the need for external manipulation,
eliminating the need for a complex and potentially costly control.