Yeast cells having reductive TCA pathway from pyruvate to succinate and overexpressing an exogenous NAD(P)+ transhydrogenase enzyme

Patent metadata

Field	Value
Publication number	US-11041176-B2
Application number	US-201715816779-A
Country	US
Kind code	B2
Filing date	Nov 17, 2017
Priority date	Jul 25, 2012
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

Yeast cells having a reductive TCA pathway from pyruvate or phosphoenolpyruvate to succinate, and which include at least one exogenous gene overexpressing an enzyme in that pathway, further contain an exogenous transhydrogenase gene.

First claim

The invention claimed is:

1. A fermentation broth comprising at least one carbon source and recombinant yeast cells engineered to produce succinate through an active reductive tricarboxylic acid (TCA) pathway from pyruvate or phosphoenolpyruvate, wherein the recombinant yeast cells are genetically modified to express a soluble nicotinamide adenine dinucleotide phosphate (NAD(P)+) transhydrogenase enzyme in the cytosol of the yeast cells by having integrated into their genomes an exogenous gene encoding the soluble NAD(P)+ transhydrogenase enzyme, wherein the recombinant yeast cells are further modified by having integrated into their genomes at least one of:
(i) an exogenous pyruvate carboxylase gene that encodes an enzyme which catalyzes the conversion of pyruvate to oxaloacetate;
(ii) an exogenous malate dehydrogenase gene which encodes an enzyme that catalyzes the conversion of oxaloacetate to malate;
(iii) an exogenous fumarase gene that encodes an enzyme which catalyzes the conversion of malate to fumarate; and
(iv) an exogenous fumarate reductase gene which encodes an enzyme which catalyzes the conversion of fumarate to succinate, and
wherein the recombinant yeast cells produce more succinate through the active reductive TCA pathway as compared to a corresponding parent yeast cell lacking the soluble NAD(P)+ transhydrogenase enzyme.

Assignees

• Cargill Inc

Inventors

• Rush Brian J
• Watts Kevin T
• Mcintosh Jr Vernon L
• Fosmer Arlene M
• Poynter Gregory M
• Mcmullin Thomas W

Classifications

• C12N15/52

  Genes encoding for enzymes or proenzymes · CPC title

• Y02E50/30

  Fuel from waste, e.g. synthetic alcohol or diesel · CPC title

• C12Y101/01

  with NAD+ or NADP+ as acceptor (1.1.1) · CPC title

• C12N9/0006

  acting on CH-OH groups as donors (1.1) · CPC title

• C12Y106/01001

  NAD(P)+ transhydrogenase (B-specific) (1.6.1.1) · CPC title