Methods and systems for 1-butanol production

A system for 1-butanol production, comprising:

• an electrochemical bioreactor module for providing reducing equivalents;
• a first engineered pathway for producing 1-butanol from acetyl-CoA, comprising acetyl-CoA acetyltransferase (AtoB, EC 2.3.1.9), 3-hydroxybutyryl-CoA dehydrogenase (Hbd, EC 1.1.1.157), 3-hydroxybutyryl-CoA dehydratase (Crt, EC 4.2.1.5), trans-enoyl-CoA reductase (Ter, EC 1.3.1.38) and aldehyde/alcohol dehydrogenase (AdhE2, EC 1.2.157/EC 1.1.1.1);
• and
• a second engineered pathway for converting pyruvate into formate without producing CO2, and converting the formate to fructose-6-phosphate;
• wherein the second pathway comprises pyruvate:formate lyase (Pfl, EC 2.3.1.54), formaldehyde dehydrogenase (Fld, EC 1.2.1.46), hexulose-6-phosphate synthase (HPS, EC 4.1.2.43), and 6-phospho-3-hexuloisomerase (HPI, EC 5.3.1.27);
• wherein the reducing equivalents are provided to one or more redox enzymes in the first and/or second engineered pathways;
• and wherein optionally the first and second engineered pathways are present in an engineered cell selected from a bacterium or a fungus.