Cell-to-cell contact mechanism modulates Starmerella bacillaris death in mixed culture fermentations with Saccharomyces cerevisiae

• Published in: International journal of food microbiology 2019-01, Vol.289, p.106-114
• Main Authors: Englezos, Vasileios, Rantsiou, Kalliopi, Giacosa, Simone, Río Segade, Susana, Rolle, Luca, Cocolin, Luca
• Format: Article
• Language: English
• Subjects: Baking yeast; Bioreactors; Cell culture; Cell-to-cell contact; Death; Fermentation; Flasks; Interactions; Kinetics; Microbial Interactions - physiology; Microbial Viability; Mixed culture; Mixed cultures; Mortality; Musts; Non-Saccharomyces; Saccharomyces cerevisiae; Saccharomyces cerevisiae - physiology; Saccharomycetales - physiology; Species; Starmerella bacillaris; Vitis - microbiology; Wine; Wine - microbiology; Wines
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2018.09.009

The use of mixed culture fermentations with selected Starmerella bacillaris and Saccharomyces cerevisiae strains is gaining winemaking attention, mainly due to their ability to enhance particular characteristics in the resulting wines. In this context, yeast interspecies interactions during fermentation have a fundamental role to determine the desired product characteristics, since they may modulate yeast growth and as a consequence metabolite production. In order to get an insight into these interactions, the growth and death kinetics of the abovementioned species were investigated in pure and mixed culture fermentations, using cv. Nebbiolo grape must. Trials were conducted in flasks but also in a double-compartment fermentation system in which cells of the two species were kept separate by a filter membrane. Although the two species had similar growth pattern during the first days of fermentation, Starm. bacillaris died earlier when tested in the flask than in the double-compartment fermentor. The early death of Starm. bacillaris seemed to be not caused by nutrient limitation nor by accumulation of growth inhibitory compounds (which were not measured in the present study). Rather, cell-to-cell contact mechanism, dependent on the presence of viable S. cerevisiae cells, appears to be responsible for the observations made. These results contribute to better understand the factors that influence Starm. bacillaris death during wine fermentations. •Yeast interspecies interactions determine wine characteristics•The growth and death kinetics of S. cerevisiae and Starm. bacillaris were investigated in pure and mixed fermentations•The early death of Starm. bacillaris is not caused by nutrient limitation or by inhibitory compounds accumulation•Cell-to-cell contact mechanism appears to be responsible for S. cerevisiae dominance