Effect of cinnamic acid on the growth and on plasma membrane H+–ATPase activity of Saccharomyces cerevisiae

Cinnamic acid and cinnamic acid derivatives occur in plants and fruits, providing a natural protection against infections by pathogenic microorganisms. They may also inhibit wine fermentation and other fruit juice fermentations by Saccharomyces cerevisiae and raise difficulties in the biological treatment of waste water from some food industries. In the present work, it is shown that cells of S. cerevisiae YPH499 grown at pH 4 and 30°C, in the presence of concentrations of cinnamic acid (20 or 35 mg/l) that reduce the maximum specific growth rate by 46 or 53%, respectively, exhibit a more active plasma membrane H+–ATPase than cells grown in its absence. This stimulatory effect was detected by assaying, during yeast growth in absence or presence of cinnamic acid, both the plasma membrane ATPase activity in crude membrane extracts and its action as a proton-pump by comparing extracellular acidification as a function of culture cell density. The lag-phase of approximately 8 h observed during cultivation in the presence of 20 mg/l cinnamic acid of yeast cells previously grown in its absence was eliminated by growing the inoculum in medium supplemented with the same concentration of cinnamic acid. These cinnamic acid adapted cells exhibited a more active plasma membrane H+–ATPase and this phenomenon may be due to and/or be among the mechanisms underlying the adaptative response to this toxic acid in yeast.