RESUMO
The growth pattern of Saccharomyces cerevisiae and Propionibacterium freudenreichii ssp. shermanii (P. shermanii; propionic acid bacteria, PABs) during cocultivation in liquid media depended on the ratio of the cells in the inoculum. An increase in the growth rate of S. cerevisiae was observed at a PAB to yeast ratio of approximately 3 : 1; higher ratios exerted adverse effects on yeast growth. The culture liquid of 18- to 24-h (young) cultures of PABs stimulated yeast growth. Although yeast growth-stimulating exometabolites of PABs were not high-molecular-weight compounds, they were thermolabile. When present in the medium at concentrations of up to 1.5%, the antimicrobial agent sodium propionate did not interfere with S. cerevisiae growth; however, it completely inhibited the growth of B. subtilis at a concentration of 0.2%.
