Kinetic Modelling of Mixed Culture Fermentation of Oenococcus oeni and Saccharomyces cerevisiae

Abstract

In order to study the kinetic changes in microbial growth, substrate consumption and product generation during the co-fermentation of Saccharomyces cerevisiae and Oenococcus oeni, indigenous O. oeni ZX-1 and MG-1 were co-inoculated with S. cerevisiae VW and AW into a model grape system, separately, and the viable count of S. cerevisiae, reducing sugar content, alcohol content, O. oeni viable count and L-malic acid content in the fermentation system were measured every day during the fermentation period. The classical Logistic, Boltzmann, SGompertz and DoseResp models were adopted to nonlinearly fit the measured data. The results showed that the Boltzmann model could better describe the growth of S. cerevisiae and the change of alcohol content; the logistic model had the best fitting effect on the change of reducing sugar content. For each of the four co-culture groups, the fitting coefficients R2 of the Boltzmann and DoseResp models for O. oeni growth and L-malic acid content change were consistent, indicating both models could well predict the growth of O. oeni and the trend of L-malic acid content during the co-fermentation process. Taken together, we concluded the tested strains O. oeni have good biocompatibility with S. cerevisiae VW and AW, and the established kinetic models can provide data support and a theoretical basis for the control of mixed culture fermentation for industrial wine production.

Keywords

• saccharomyces cerevisiae; oenococcus oeni; co-fermentation; fermentation kinetics; fitting coefficient