Microbial Growth Modification by Compressed Gases and Hydrostatic Pressure

Abstract

Studies of the growth-modifying actions for Escherichia coli, Saccharomyces cerevisiae, and Tetrahymena thermophila of helium, nitrogen, argon, krypton, xenon, and nitrous oxide led to the conclusion that there are two definable classes of gases. Class 1 gases, including He, N2, and Ar, are not growth inhibitors; in fact, they can reverse the growth inhibitory action of hydrostatic pressures. Class 2 gases, including Kr, Xe, and N20, are potent growth inhibitors at low pressures. For example, at 24°C, 50% growth-inhibitory pressures of N20 were found to be ca. 1.7 MPa for E. coli, 1.0 MPa for S. cerevisiae, and 0.5 MPa for T. thermophila. Class 1 gases could act as potentiators for growth inhibition by N2O, O, Kr, or Xe. Hydrostatic pressure alone is known to reverse N20 inhibition of growth, but we found that it did not greatly alter oxygen toxicity. Therefore, potentiation by class 1 gases appeared to be a gas effect rather than a pressure effect. The temperature profile for growth inhibition of S. cerevisiae by N2O revealed an optimal temperature for cell resistance of ca. 24°C, with lower resistance at higher and lower temperatures. Overall, it appeared that microbial growth modification by hyperbaric gases could not be related to their narcotic actions but reflected definably different physiological actions.

An optical oxygen sensor and reaction vessel for high‐pressure applications

“…The measurement of oxygen consumption by S. cerevisiae at elevated hydrostatic pressures illustrated the utility of this type of sensor. Previous studies have shown a decrease in growth rate in S. cerevisiae cultures at increased hydrostatic pressures (Thom and Marquis 1984;Marquis 1993). Because the optrode is insensitive to pressure fluctuations, it is possible to continuously monitor oxygen tension within the reaction chamber while simultaneously altering the hydrostatic pressure.…”

Transport and Kinetics in Sandwiched Membrane Bioreactors

“…2 an attempt was made to fit the experimental data to eq 40. With respect to the yeast cell under a high-pressure study, P,,, is known in the literature to be 19898.6 kPa gauge (=2842.4 psig) (Furui and Yamashita, 1983;Kitano and Ise, 1988;Taylor and Jannasch, 1976;Miller et al, 1988;Thibault et al, 1987;Thom and Marquis, 1984;Zo-bel and Budge, 1965). By using the above P,, and applying a regression analysis, the constants a and / 3 were found to be 0.25 and 0.775.…”

Gaseous environments modify physiology in the brewing yeastSaccharomyces cerevisiaeduring batch alcoholic fermentation

“…Influence of gaseous environment and E h on yeast growth was reported previously in the literature. However, Thom and Marquis (1984) showed that hydrogen and helium gases used for compression of culture were not growth inhibitory for S. cerevisiae. Influence of gas and ⁄ or E h on yeast growth could be dependent on yeast strain and ⁄ or medium culture.…”