The effect of polysaccharide-degrading wine yeast transformants on the efficiency of wine processing and wine flavour

• Published in: Journal of biotechnology 2006-10, Vol.125 (4), p.447-461
• Main Authors: Louw, C., La Grange, D., Pretorius, I.S., van Rensburg, P.
• Format: Article
• Language: English
• Subjects: alcoholic fermentation; Aroma; Aspergillus niger; Biological and medical sciences; Biotechnology; Butyrivibrio fibrisolvens; Chromatography, Gas; Cloning, Molecular; endo-1,4-beta-glucanase; endo-1,4-beta-xylanase; Erwinia carotovora; Erwinia chrysanthemi; Fermentation - genetics; flavor; Food Handling; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, Fungal - physiology; genetically engineered microorganisms; Glucanase; Hypocrea jecorina; Industrial Microbiology - methods; Mutagenesis, Insertional - methods; Organisms, Genetically Modified - genetics; pectate lyase; Pectinase; Pectobacterium carotovorum; Pectobacterium carotovorum - genetics; Pectobacterium chrysanthemi; Pectobacterium chrysanthemi - genetics; polygalacturonase; Polygalacturonase - genetics; Polysaccharides - metabolism; Recombinant Proteins - genetics; Recombinant wine yeast; red wines; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Transformation, Genetic; transgenes; Vitaceae; Wine - analysis; Wine - microbiology; Wine colour; Wine processing; wine quality; wine yeasts; winemaking; Xylan Endo-1,3-beta-Xylosidase - genetics; Xylanase; Xylosidases - genetics; Yeasts - genetics; Yeasts - metabolism
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2006.03.029

Commercial polysaccharase preparations are applied to winemaking to improve wine processing and quality. Expression of polysaccharase-encoding genes in Saccharomyces cerevisiae allows for the recombinant strains to degrade polysaccharides that traditional commercial yeast strains cannot. In this study, we constructed recombinant wine yeast strains that were able to degrade the problem-causing grape polysaccharides, glucan and xylan, by separately integrating the Trichoderma reesei XYN2 xylanase gene construct and the Butyrivibrio fibrisolvens END1 glucanase gene cassette into the genome of the commercial wine yeast strain S. cerevisiae VIN13. These genes were also combined in S. cerevisiae VIN13 under the control of different promoters. The strains that were constructed were compared under winemaking conditions with each other and with a recombinant wine yeast strain expressing the endo-β-1,4-glucanase gene cassette ( END1) from B. fibrisolvens and the endo-β-1,4-xylanase gene cassette ( XYN4) from Aspergillus niger, a recombinant strain expressing the pectate lyase gene cassette ( PEL5) from Erwinia chrysanthemi and the polygalacturonase-encoding gene cassette ( PEH1) from Erwinia carotovora. Wine was made with the recombinant strains using different grape cultivars. Fermentations with the recombinant VIN13 strains resulted in significant increases in free-flow wine when Ruby Cabernet must was fermented. After 6 months of bottle ageing significant differences in colour intensity and colour stability could be detected in Pinot Noir and Ruby Cabernet wines fermented with different recombinant strains. After this period the volatile composition of Muscat d’Alexandria, Ruby Cabernet and Pinot Noir wines fermented with different recombinant strains also showed significant differences. The Pinot Noir wines were also sensorial evaluated and the tasting panel preferred the wines fermented with the recombinant strains.