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High enthalpy and low enthalpy death in Saccharomyces cerevisiae induced by acetic acid
Author(s) -
Pinto Isabel,
Cardoso Helena,
Leão Cecélia,
van Uden N.
Publication year - 1989
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260331019
Subject(s) - acetic acid , enthalpy , ethanol , yeast , fermentation , chemistry , nuclear chemistry , biochemistry , thermodynamics , physics
Acetic acid at concentrations as may occur during vinification and other alcoholic yeast fermentations induced death of glucose‐grown cell populations of Saccharomyces cerevisiae IGC 4072 at temperatures at which thermal death was not detectable. The Arrhenius plots of specific death rates with various concentrations of acetic acid (0–2%, w/v) pH 3.3 were linear and could be decomposed into two distinct families of parallel straight lines, indicating that acetic acid induced two types of death: (1) High enthalpy death (HED) predominated at lower acetic acid concentrations (> 0.5%, w/v) and higher temperatures; its enthalpy of activation (Δ H ≠ ) approached that of thermal death (12.4 × 10 4 cal/mol); (2) Low enthalpy death (LED) predominated at higher acetic acid concentrations and lower temperatures with Δ H ≠ of 3.9 × 10 4 cal/mol. While the Δ H ≠ values for HED induced by acetic acid were similar with those reported earlier for HED induced by other fermentation endproducts, the values for the entropy coefficients were different: 127–168 entropy units mol −1 L for acetic acid as compared with 3.6–5.1 entropy units mol −1 L for ethanol, which agreed with experimental results indicating that acetic acid is over 30‐times more toxic than ethanol with respect to yeast cell viability at high process temperatures.