Harnessing noncanonical redox cofactors to advance synthetic assimilation of one-carbon feedstocks.

One-carbon (C1) feedstocks, such as carbon monoxide (CO), formate (HCOH), methanol (CHOH), and methane (CH), can be obtained either through stepwise electrochemical reduction of CO with renewable electricity or via processing of organic side streams. These C1 substrates are increasingly investigated in biotechnology as they can contribute to a circular carbon economy. In recent years, noncanonical redox cofactors (NCRCs) emerged as a tool to generate synthetic electron circuits in cell factories to maximize electron transfer within a pathway of interest.