Genetic switches for butanol production

摘要

The invention relates to suitable screening strategies for evaluating various candidate promoters for differential gene expression during the propagation and production phases of a fermentation process. The invention also relates to recombinant host cells that comprise identified promoter nucleic acid sequences and methods for producing fermentation products employing the same.

主权项

1. A method of producing butanol or 2-butanone comprising:
A) contacting a recombinant host cell comprising a heterologous polynucleotide, said heterologous polynucleotide comprising i) a promoter nucleic acid sequence, wherein the promoter nucleic acid sequence is selected from SEQ ID NO: 775, 776, 777, 778, 772, 773, 768, 769, or 711; and ii) a nucleic acid sequence encoding a biocatalyst polypeptide, wherein the biocatalyst polypeptide catalyzes a substrate to product conversion of pyruvate to acetolactate; with a carbon substrate under a first set of conditions; and B) contacting the recombinant host cell with a carbon substrate under a second set of conditions; wherein the first set of conditions and second set of conditions differ and wherein the nucleic acid sequence encoding a biocatalyst polypeptide is differentially expressed under the first set of conditions than under the second set of conditions; and wherein the host cell produces butanol or 2-butanone under at least one of the first set or the second set of conditions.