Engineered microorganisms for producing n-butanol and related methods

A recombinant microorganism expressing a heterologous pathway for the conversion of a carbon source to n-butanol, the heterologous pathway comprising the following substrate to product conversions:

• acetyl-CoA to acetoacetyl-CoA, acetoacetyl-CoA to hydroxybutyryl-CoA, hydroxybutyryl-CoA to crotonoyl-CoA, crotonyl-CoA to butyryl-CoA, butyryl-CoA to butyraldehyde, and butyraldehyde to n-butanol,
• the recombinant microorganism engineered to inactivate one or more native pathways for the conversion of a substrate to a product wherein the substrate is pyruvate or acetylCoA,
• the recombinant microorganism further engineered to activate at least one of an anaerobically active pyruvate dehydrogenase, a NADH dependent formate dehydrogenase, and a heterologous pathway for the conversion of glycerol to pyruvate, and
• the recombinant microorganism capable of producing n-butanol at a yield of at least 5 percent of theoretical.

A recombinant microorganism expressing a heterologous pathway for the conversion of a carbon source to n-butanol, the heterologous pathway comprising the following substrate to product conversions:

• acetyl-CoA to acetoacetyl-CoA;
• acetoacetyl-CoA to hydroxybutyryl-CoA;
• hydroxybutyryl-CoA to crotonoyl-CoA;
• crotonyl-CoA to butyryl-CoA;
• butyryl-CoA to butyraldehyde, and butyraldehyde to n-butanol,
• the recombinant microorganism engineered to inactivate one or more native pathways for the conversion of a substrate to a product wherein the substrate is pyruvate or acetylCoA, the recombinant microorganism capable of producing n-butanol at a yield of at least 2% percent of theoretical.

Recombinant microorganism capable of producing mixtures of butyrate and n-butanol at a yield of at least 5 percent of theoretical, the recombinant microorganism obtainable by:

• engineering the microorganism to activate an NADH-dependent heterologous pathway for conversion of a carbon source to butyrate through production of one or more metabolic intermediates;
• engineering the microorganism to activate an NADH-dependent heterologous pathway for conversion of a carbon source to n-butanol through production of one or more metabolic intermediates;
• and
• engineering the microorganism to inactivate a native pathway for the conversion of a substrate to a product wherein the substrate is one of the one or more metabolic intermediates.