The influence of temperature (15° −40°C) and pH (2.5–6.0) on the continuous growth of bakers' yeast (Saccharomyces cerevisiae) at steady state in 1% ethanol was investigated. Optimal temperature and pH were 30°C and 4.5, respectively. The short-term effect of ethanol concentration (0.1–10.0%) on the yeast growth was assessed in batch culture. Up to 1% of ethanol, the yeast growth increased in function of the ethanol concentration in the medium. The biomass reached a maximum within the interval of 1–4% of ethanol (7.9 and 31.6 g/L, respectively) and decreased at higher concentrations. The residual ethanol concentration in the medium increased rapidly when the initial ethanol concentration exceeded 4%. The best-fit model obtained for growth inhibition as a function of ethanol concentrations was that of Tseng and Wayman: μmS/)K + S( − i (S − Sθ). With this model, the specific growth rate (μ) decreased linearly as the ethanol concentration increased between the threshold value (Sθ) of 11.26 g/L to be fully inhibited at 70.00 g/L (S;) an inhibition constant (i) of 0.0048 g L−1 h−1, a maximum specific growth rate (μm) of 0.284 h−1, and a saturation constant (K) of 0.611 g/L were obtained.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.