Genetically modified wine yeasts and risk assessment studies covering different steps within the wine making process

Table 1 Potential benefits of genetically modified (gm) wine yeasts in different wine making steps

Wine characteristic	Enhancement	Benefit	Reference
Wine aroma
Fermentation bouquet	Enhancement of esterase activity (ATF1)	More fruitiness	Lilly et al. 2000
Varietal aroma; red wine colour	Enhancement of glycosides splitting hydrolases	More varietal character	Perez-Gonzalez et al. 1993; Ganga et al. 1999; Louw et al. 2006; van Rensburg et al. 2007; Gil and Vallés 2001
Varietal aroma; red wine colour	Enhancement of S-linalool synthase	de novo production of aromatic terpenes	Herrero et al. 2008
Taste	Enhancement of GPD1-enzyme; enhancement of H₂O-NADH oxidase	More glycerol, extract and full-body; reduced alcohol production	Michnick et al. 1997; Heux et al. 2006
	Malate degradation; lactate production;	Balanced acidity	Volschenk et al. 1997,2001; Dequin et al. 1999
	Enhancement of yeast autolysis	Higher complexity and maturity	Cebollero et al. 2009
Must/wine treatment
Grape must	Enhancement of pectinase activity; enhancement of protease activity	Improved filtration alternative for bentonite	Gonzalez-Candelas et al. 1995
Young wine	Enhancement of glucanase activity	Improved filtration	Perez-Gonzalez et al. 1993
Wine and human health
Wine hygiene	Production of bacteria inhibiting proteins	Lower SO₂-requirement	Schoeman et al. 1999
Health promotion	Enhancement of existing enzymes and/or introduction of external enzymes	Hydrolyses of bound resveratrol; formation of various vitamins and unsaturated fatty acids	Gonzalez-Candelas et al. 2000; Pretorius 2000 (review)

ISSN: 1869-2044