Abstract The asymmetric bioreduction of C= C-bonds bearing an electron-withdrawing group, such as an aldehyde, ketone, imide, nitro, carboxylic acid, or ester moiety by a novel enoate reductase from Zymomonas mobilis and Old Yellow Enzymes OYE 1–3 from yeasts furnished the corresponding saturated products in up to> 99% ee. Depending on the substrate type, stereocontrol was achieved by variation of the substrate structure, by ...