Fungicidal mechanism of chlorine dioxide on Saccharomyces cerevisiae

The fungicidal mechanism of chlorine dioxide on Saccharomyces cerevisiae was investigated. During S. cerevisiae inactivation by ClO2, protein, DNA, and ion leakage, enzyme activity, genomic DNA structure, and cell ultrastructure were examined. Protein and DNA leakages were not observed, while ion leakages of K+, Ca2+, and Mg2+ were detected and were related to the inactivation rate. The glucose-6-phosphate dehydrogenase, citrate synthase, and phosphofructokinase activities were inhibited and were also correlated with the inactivation rate. Genomic DNA structure was not damaged except for an extremely high ClO2 concentration (100 mg L-1). Electron micrographs showed that cell surface damage was pronounced and disruption in inner cell components was also apparent. The ion leakage, the inhibition of key enzyme activities of metabolic pathway, and the alteration of cell structure were critical events in S. cerevisiae inactivation by ClO2.