A model based on factorial design to predict the evolution of Brettanomyces sp. population as function of environmental conditions in winemaking

Contamination of wines by Brettanomyces is an increasing industrial problem. Here, we propose a model able to predict the evolution of a Brettanomyces population as function of environmental conditions as temperature, ethanol concentration or dioxide sulfur concentration. Polynomial models obtained from factorial design realized on synthetic medium gave the lag phase, the specific growth rate and the maximal biomass concentration as function of these medium factors. A logistic model was then used with the determined growth parameters to represent the evolution of Brettanomyces population. The factorial design showed that temperature has an important effect on maximal biomass concentration and specific growth rate but a negligible effect on lag phase. Conversely, molecular sulfur dioxide had an important effect on lag phase but a little influence on growth parameters. Ethanol concentration played an important role on the three parameters tested.