Modeling of the fermentation behavior of Starmerella bacillaris

Starmerella bacillaris has been proposed as a non-Saccharomyces species candidate to be used in mixed fermentations with Saccharomyces cerevisiae for the production of wine. Among the prospective applications, reductions in ethanol content and the acetic acid produced from high sugar musts have attracted particular attention. In this study, we described the fermentation behavior of six strains of S. bacillaris in grape must with initial sugar concentration ranging from 200 to 330 g/L. Time (days of fermentation) was a second variable that was monitored for its influence on fermentation. Response surface methodology was employed to model the behavior of the strains. The six strains generally behaved uniformly. Residual sugar concentration and production of ethanol, glycerol, and acetic acid mainly depended on time. Initial sugar concentration in the must was positively associated with residual glucose in musts with higher initial sugar concentration. Similarly, malic acid consumption showed a dependence on time and sugar concentration and was inhibited in musts with a higher sugar content. The behavior of S. bacillaris strains can be considered compatible with enological practices that may involve mixed fermentation with S. cerevisiae.