D'Amore T, Panchal C J, Stewart G G
Production Research Department, Labatt Brewing Company Limited, London, Ontario, Canada.
Appl Environ Microbiol. 1988 Jan;54(1):110-4. doi: 10.1128/aem.54.1.110-114.1988.
An intracellular accumulation of ethanol in Saccharomyces cerevisiae was observed during the early stages of fermentation (3 h). However, after 12 h of fermentation, the intracellular and extracellular ethanol concentrations were similar. Increasing the osmotic pressure of the medium caused an increase in the ratio of intracellular to extracellular ethanol concentrations at 3 h of fermentation. As in the previous case, the intracellular and extracellular ethanol concentrations were similar after 12 h of fermentation. Increasing the osmotic pressure also caused a decrease in yeast cell growth and fermentation activities. However, nutrient supplementation of the medium increased the extent of growth and fermentation, resulting in complete glucose utilization, even though intracellular ethanol concentrations were unaltered. These results suggest that nutrient limitation is a major factor responsible for the decreased growth and fermentation activities observed in yeast cells at higher osmotic pressures.
在发酵早期阶段（3小时）观察到酿酒酵母细胞内有乙醇积累。然而，发酵12小时后，细胞内和细胞外的乙醇浓度相似。提高培养基的渗透压会导致发酵3小时时细胞内与细胞外乙醇浓度的比值增加。与前一种情况一样，发酵12小时后细胞内和细胞外的乙醇浓度相似。提高渗透压也会导致酵母细胞生长和发酵活性降低。然而，向培养基中补充营养物质会增加生长和发酵的程度，即使细胞内乙醇浓度未改变，也能实现葡萄糖的完全利用。这些结果表明，营养限制是导致在较高渗透压下酵母细胞生长和发酵活性降低的主要因素。
