Effects of compressed unsaturated hydrocarbon gases on yeast growth.

The effect of compressed unsaturated hydrocarbon gases on the growth of the yeast Saccharomyces cerevisiae was investigated by microcalorimetry. The growth thermograms showed that unsaturated hydrocarbon gases inhibited yeast growth. As an approach to determining the comparative toxicity of unsaturated hydrocarbon gases, we determined the 50% inhibitory pressure (IP(50)) and the minimum inhibitory pressure (MIP). On the basis of the IP(50) and MIP values, the inhibitory potency of the gases increased in the order ethylene < propylene < 1-butene. Additionally, scanning electron microscopy showed that cells treated with unsaturated hydrocarbon gases were damaged, including invagination of the cell surface.