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Physiological and genetic engineering of cytosolic redox metabolism in Saccharomyces cerevisiae for improved glycerol production

Paper ID Volume ID Publish Year Pages File Format Full-Text
31815 44841 2006 11 PDF Available
Title
Physiological and genetic engineering of cytosolic redox metabolism in Saccharomyces cerevisiae for improved glycerol production
Abstract

Previous metabolic engineering strategies for improving glycerol production by Saccharomyces cerevisiae were constrained to a maximum theoretical glycerol yield of 1 mol·(mol glucose)−1 due to the introduction of rigid carbon, ATP or redox stoichiometries. In the present study, we sought to circumvent these constraints by (i) maintaining flexibility at fructose-1,6-bisphosphatase and triosephosphate isomerase, while (ii) eliminating reactions that compete with glycerol formation for cytosolic NADH and (iii) enabling oxidative catabolism within the mitochondrial matrix. In aerobic, glucose-grown batch cultures a S. cerevisiae strain, in which the pyruvate decarboxylases the external NADH dehydrogenases and the respiratory chain-linked glycerol-3-phosphate dehydrogenase were deleted for this purpose, produced glycerol at a yield of 0.90 mol·(mol glucose)−1. In aerobic glucose-limited chemostat cultures, the glycerol yield was ca. 25% lower, suggesting the involvement of an alternative glucose-sensitive mechanism for oxidation of cytosolic NADH. Nevertheless, in vivo generation of additional cytosolic NADH by co-feeding of formate to aerobic, glucose-limited chemostat cultures increased the glycerol yield on glucose to 1.08 mol mol−1. To our knowledge, this is the highest glycerol yield reported for S. cerevisiae.

Keywords
Saccharomyces cerevisiae; Glycerol; Cofactor; Cytosolic redox metabolism; Metabolic engineering; NADH dehydrogenase
First Page Preview
Physiological and genetic engineering of cytosolic redox metabolism in Saccharomyces cerevisiae for improved glycerol production
Publisher
Database: Elsevier - ScienceDirect
Journal: Metabolic Engineering - Volume 8, Issue 6, November 2006, Pages 532–542
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering