Selective Electroenzymatic Oxyfunctionalization by Alkane Monooxygenase in a Biofuel Cell

Aliphatic synthetic intermediates with high added value are generally produced from alkane sources (e.g., petroleum) by inert carbon-hydrogen (C-H) bond activation using classical chemical methods (i.e. high temperature, rare metals). As an alternative approach for these reactions, alkane monooxygenase from Pseudomonas putida (alkB) is able to catalyze the difficult terminal oxyfunctionalization of alkanes selectively and under mild conditions. Herein, we report an electrosynthetic system using an alkB biocathode which produces alcohols, epoxides, and sulfoxides through bioelectrochemical hydroxylation, epoxidation, sulfoxidation, and demethylation. The capacity of the alkB binding pocket to protect internal functional groups is also demonstrated. By coupling our alkB biocathode with a hydrogenase bioanode and using H₂ as a clean fuel source, we have developed and characterized a series of enzymatic fuel cells capable of oxyfunctionalization while simultaneously producing electricity.