Methods for the improvement of product yield and production in a microorganism through the addition of alternate electron acceptors

摘要

The present invention provides for novel metabolic pathways to reduce or eliminate glycerol production and increase product formation. More specifically, the invention provides for a recombinant microorganism comprising a deletion of one or more native enzymes that function to produce glycerol and/or regulate glycerol synthesis and one or more native and/or heterologous enzymes that function in one or more engineered metabolic pathways to convert a carbohydrate source, such as lignocellulose, to a product, such as ethanol, wherein the one or more native and/or heterologous enzymes is activated, upregulated, or downregulated. The invention also provides for a recombinant microorganism comprising one or more heterologous enzymes that function to regulate glycerol synthesis and one or more native and/or heterologous enzymes that function in one or more engineered metabolic pathways to convert a carbohydrate source to ethanol, wherein said one or more native and/or heterologous enzymes is activated, upregulated or downregulated.

主权项

1. A recombinant microorganism comprising:
(a) a deletion of one or more native enzymes that function to produce glycerol and/or regulate glycerol synthesis, wherein said one or more enzymes is encoded by a glycerol-3-phosphate dehydrogenase (gpd1), glycerol-3-phosphate dehydrogenase (gpd2) glycerol 3-phosphatase 1′, glycerol 3-phosphatase 2 or fps1 polynucleotide; and (b) one or more native and/or heterologous enzymes that function in one or more engineered metabolic pathways to convert a carbohydrate source to ethanol, wherein one of said metabolic pathways comprises conversion of pyruvate to acetyl-CoA and formate by a pyruvate formate lyase, wherein one of said metabolic pathways comprises conversion of acetyl-CoA to ethanol by an acetaldehyde dehydrogenase, alcohol dehydrogenase, or a bifunctional acetaldehyde/alcohol dehydrogenase, and wherein said one or more native and/or heterologous enzymes is activated, upregulated or downregulated.