Abstract
Ethanol, octanoic and decanoic acids are known toxic products of alcoholic fermentation and inhibit yeast functions such as growth and fermentation. pH-stat measurements showed that, in a concentration range up to 20 mg/l, octanoic and decanoic acids increase the rate of passive H+ influx across the plasma membrane of Saccharomyces cerevisiae IGC 3507. Decanoic acid was more active than octanoic acid, which agrees with its higher liposolubility. The fatty acids probably act as H+ carriers, since the magnitude of the effect depended on pH and correlated with the concentration of protonated fatty acids. Esterification of the fatty acids partially abolished the enhancing effect on passive H+ influx. Passive H+ influx showed saturation kinetics with half-maximal activity at 6.6 μM H+ (pH 5.2). Contrary to previous findings, ethanol inhibited H+ influx exponentially up to a concentration of 8% (v/v). At higher concentrations, ethanol reactivated H+ influx; the original rate of H+ uptake was reached at 14% (v/v) ethanol. In the same concentration ranges that affected passive H+ influx, ethanol, octanoic and decanoic acids inhibited the fermentation rate. This inhibitory effect of the fatty acids on fermentation rate depended on liposolubility, pH, and esterification in the same way as that found for their effect on passive H+ influx. Inhibition of fermentation by octanoic and decanoic acids could therefore result from their effect on the rate of passive H+ influx.
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References
Atlas RM (1984) Microbiology: fundamentals and applications. Macmillan, New York, pp 109–110
Barnett JA, Sims AP (1976) Some physiological observations on the uptake of D-glucose and 2-deoxy-D-glucose by starving and exponentially growing yeasts. Arch Microbiol 111:185–192
Borst-Pauwels GWFH (1981) Ion transport in yeast. Biochim Biophys Acta 650:88–127
Cartwright CP, Juroszek J, Beaven MJ, Ruby FMS, De Morais SMF, Rose AH (1986) Ethanol dissipates the proton-motive force across the plasma membrane of Saccharomyces cerevisiae. J Gen Microbiol 132:369–377
Casey GP, Ingledew WM (1985) Reevaluation of alcohol synthesis and tolerance in brewer's yeast. Master Brew Assoc Am (Tech Q) 22:133–141
D'Amore T, Stewart GG (1987) Ethanol tolerance of yeast. Enzyme Microb Technol 9:322–330
Dombek KM, Ingram LO (1986) Determination of the intracellular concentration of ethanol in Saccharomyces cerevisiae during fermentation. Appl Environ Microbiol 51:197–200
Eddy AA (1982) Mechanisms of solute transport into selected eukaryotic micro-organisms. Adv Microb Physiol 23:1–78
Eisenthal R, Cornish-Bowden A (1974) The direct linear plot. Biochem J 139:715–720
Freese E, Sheu C, Galliers E (1973) Function of lipophilic acids as anti-microbial food additives. Nature 241:321–325
Goffeau A, Slayman CW (1981) The protein-translocating ATPase of the fungal plasma membrane. Biochim Biophys Acta 639:197–223
Grunwald E, Berkowitz BJ (1951) The measurement and correlation of acid dissociation constants for carboxylic acids in the system ethanol-water. Activity coefficients and empirical activity functions. J Am Chem Soc 73:4939–4944
Guijarro JM, Lagunas R (1984) Saccharomyces cerevisiae does not accumulate ethanol against a concentration gradient. J Bacteriol 160:874–878
Ingram LO (1986) Microbial tolerance to alcohols: role of the cell membrane. Trends Biotechnol 4:40–44
Ingram LO, Dombek KM (1987) On the evolution of alcohol tolerance in microorganisms. NATO ASI Ser Ser A Life Sci 128:131–138
Juroszek J, Feuillat M, Charpentier C (1987) Effect of ethanol on the glucose-induced movements of protons across the plasma membrane of Saccharomyces cerevisiae NCYC 431. Can J Microbiol 33:93–97
Lafon-Lafourcade S, Geneix C, Ribereau-Gayon P (1984) Inhibition of alcoholic fermentation of grape must by fatty acids produced by yeasts and their elimination by yeast ghosts. Appl Environ Microbiol 47:1246–1249
Leao C, Van Uden N (1984) Effects of ethanol and other alkanols on passive proton influx in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta 774:43–48
Lobo Z, Maitra PK (1977) Resistance to 2-deoxyglucose in yeast. A direct selection of mutants lacking glucose-phosphorylating enzymes. Mol Gen Genet 157:297–300
Loureiro V, Ferreira HG (1983) On the intracellular accumulation of ethanol in yeast. Biotechnol Bioeng 25:2263–2269
Novak M, Strehaiano P, Moreno M, Goma G (1981) Alcoholic fermentation: on the inhibitory effect of ethanol. Biotechnol Bioeng 23:201–211
Sa-Correia I (1986) Synergistic effects of ethanol, octanoic and decanoic acids on the kinetics and the activation parameters of thermal death in Saccharomyces bayanus. Biotechnol Bioeng 28:761–763
Sa-Correia I, Salgueiro SP, Viegas CA, Novais JM (1989) Leakage induced by ethanol, octanoic and decanoic acids in Saccharomyces cerevisiae. Yeast 5 (Special Issue):S123–127
Sigler K, Knotkova A, Kotyk A (1981a) Factors governing substrate-induced generation and extrusion of protons in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta 643:572–582
Sigler K, Kotyk A, Knotkova A, Opekarova M (1981b) Processes involved in the creation of buffering capacity and in substrate-induced proton extrusion in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta 643:583–592
Van Uden N (1967) Transport-limited fermentation and growth of Saccharomyces cerevisiae and its competitive inhibition. Arch Microbiol 58:155–168
Van Uden N (1985) Ethanol toxicity and ethanol tolerance in yeast. Annu Rep Ferment Process 8:11–58
Viegas CA, Sa-Correia I (1991) Activation of plasma membrane ATPase of Saccharomyces cerevisiae by octanoic acid. J Gen Microbiol 137:645–651
Viegas CA, Sa-Correia I, Novais JM (1985) Synergistic inhibition of the growth of Saccharomyces bayanus by ethanol and octanoic or decanoic acids. Biotechnol Lett 7:611–614
Viegas CA, Rosa FM, Sa-Correia I, Novais JM (1989) Inhibition of yeast growth by octanoic and decanoic acids produced during ethanolic fermentation. Appl Environ Microbiol 55:21–28
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Stevens, S., Hofmeyr, JH.S. Effects of ethanol, octanoic and decanoic acids on fermentation and the passive influx of protons through the plasma membrane of Saccharomyces cerevisiae . Appl Microbiol Biotechnol 38, 656–663 (1993). https://doi.org/10.1007/BF00182806
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DOI: https://doi.org/10.1007/BF00182806