Oxygen availability and strain combination modulate yeast growth dynamics in mixed culture fermentations of grape must with Starmerella bacillaris and Saccharomyces cerevisiae.

Starmerella bacillaris (synonym Candida zemplinina) is a non-Saccharomyces yeast that has been proposed\r\nas a co-inoculant of selected Saccharomyces cerevisiae strains in mixed culture fermentations to enhance\r\nthe analytical composition of the wines. In order to acquire further knowledge on the metabolic interactions\r\nbetween these two species, in this study we investigated the impact of oxygen addition and\r\ncombination of Starm. bacillaris with S. cerevisiae strains on the microbial growth and metabolite production.\r\nFermentations were carried out under two different conditions of oxygen availability. Oxygen\r\navailability and strain combination clearly influenced the population dynamics throughout the\r\nfermentation. Oxygen concentration increased the survival time of Starm. bacillaris and decreased the\r\ngrowth rate of S. cerevisiae strains in mixed culture fermentations, whereas it did not affect the growth of\r\nthe latter in pure culture fermentations. This study reveals new knowledge about the influence of oxygen\r\navailability on the successional evolution of yeast species during wine fermentation.