Secretion of functional formate dehydrogenase in Pichia pastoris.

Biofuels are an important tool for the reduction of carbon dioxide and other greenhouse emissions. NAD+-dependent formate dehydrogenase has been previously shown to be capable of the electrochemical reduction of carbon dioxide into formate, which can be ultimately converted to methanol. We established that a functional enzyme, tagged for immobilization, could be continuously secreted by Pichia pastoris. The protein can be easily separated from the growth media and its activity remains constant over an extended period of time. This is an important first step in creating a self-sustaining system capable of producing biofuels with minimal resources and space required.