Resting Escherichia coli as Chassis for Microbial Electrosynthesis: Production of Chiral Alcohols.

Chiral alcohols constitute important building blocks that can be produced enantioselectively using NAD(P)H-dependent oxidoreductases. For NAD(P)H regeneration, electricity delivers the cheapest reduction equivalents. Enzymatic electrosynthesis suffers from cofactor and enzyme instability, whereas microbial electrosynthesis (MES) exploits whole cells. Here, we demonstrate MES using resting Escherichia coli as biocatalytic chassis for a production platform towards fine chemicals using electric power. This chassis was exemplified for the synthesis of chiral alcohols by using a NADPH-dependent alcohol dehydrogenase from Lactobacillus brevis for synthesis of (R)-1-phenylethanol from acetophenone. The E. coli strain and growth conditions affected the performance. Maximum yields of 39.4±5.7% at a coulombic efficiency of 50.5±6.0% with eeR >99% was demonstrated at a rate of 83.5±13.9 μM h-1, confirming the potential of MES for synthesis of high value compounds.