A Survey of Industrial Strains ofSaccharomyces cerevisiaeReveals Numerous Altered Patterns of Maltose and Sucrose Utilisation

A model fermentation system was used to define the abilities of 25 Saccharomyces cerevisiae strains, representing the brewing, baking, winemaking and distilling industries, to utilise maltose and sucrose in the presence of glucose and fructose. Three categories of sucrose and maltose utilisers were observed; repressible, constitutive and non-utilisers. In terms of fermentation kinetics, neither high rates of sucrose hydrolysis nor the early onset of maltose utilisation were correlated with reduced fermentation duration in the experimental system used. Instead better positive correlations were found between this parameter and biomass formation (R2 = 0.62) and rates of maltose or monosaccharide removal (R2 = 0.87 and 0.82, respectively). Additionally, invertase activity of brewing strains was seen to occur in two forms: cell-associated and non-cell-associated. This survey exposed a number of novel phenotypes that could be harnessed as a means of producing strains with rapid and efficient utilisation of fermentable carbohydrates.