Glycerol overproduction by engineered Saccharomyces cerevisiae wine yeast strains leads to substantial changes in by-product formation and to a stimulation of fermentation rate in stationary phase

• Published in: Applied and Environmental Microbiology Vol. 65; no. 1; pp. 143 - 149
• Main Authors: Remize, F, Roustan, J.L, Sablayrolles, J.M, Barre, P, Dequin, S
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 1999
• Subjects: Biological and medical sciences; Biotechnology; Ecology, environment; Fermentation; food microbiology; food processing; Fundamental and applied biological sciences. Psychology; Genetic engineering; Genetic technics; horticultural crops; Life Sciences; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Modification of gene expression level; Physiology and Biotechnology; Saccharomyces cerevisiae; Wines; Yeast; Recombinant microorganism; Yeast; Ethanol; Enzyme; Glycerol; Gene overexpression; Enology; Wine yeast; Fungi; Glyceraldehyde-3-phosphate dehydrogenase (phosphorylating); Batchwise; Alcoholic fermentation; Production; Microorganism culture; Ascomycetes; Oxidoreductases; Saccharomyces cerevisiae; By product; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.65.1.143-149.1999

Six commercial wine yeast strains and three nonindustrial strains (two laboratory strains and one haploid strain derived from a wine yeast strain) were engineered to produce large amounts of glycerol with a lower ethanol yield. Overexpression of the GPD1 gene, encoding a glycerol-3-phosphate dehydrogenase, resulted in a 1.5- to 2.5-fold increase in glycerol production and a slight decrease in ethanol formation under conditions simulating wine fermentation. All the strains overexpressing GPD1 produced a larger amount of succinate and acetate, with marked differences in the level of these compounds between industrial and nonindustrial engineered strains. Acetoin and 2,3-butanediol formation was enhanced with significant variation between strains and in relation to the level of glycerol produced. Wine strains overproducing glycerol at moderate levels (12 to 18 g/liter) reduced acetoin almost completely to 2,3-butanediol. A lower biomass concentration was attained by GPD1-overexpressing strains, probably due to high acetaldehyde production during the growth phase. Despite the reduction in cell numbers, complete sugar exhaustion was achieved during fermentation in a sugar-rich medium. Surprisingly, the engineered wine yeast strains exhibited a significant increase in the fermentation rate in the stationary phase, which reduced the time of fermentation.