The Inhibition of Sulfhydryl Enzymes as the Basis of the Bactericidal Action of Chlorine

Abstract

A certain amt. of Cl is shown to be necessary to kill a given number of bacteria. This minimal bactericidal amt. also inhibits the glucose oxidation of the cells, the 2 effects occurring together. Since this action occurs with very small amts. of Cl, (ca. 160 [gamma] Cl/mg. bacterial N), an effect upon enzyme systems may be inferred from the known action of other trace substances. Cl is shown to be a powerful sulfhydryl enzyme inhibitor, irreversibly inactiviting by its oxidizing action such classical sulfhydryl enzymes as succinoxidase and papain. An example of an essential enzyme in bacteria sensitive to such oxidation is the aldolase enzyme isolated from Escherichia coli. This enzyme plays an essential role in glucose breakdown and is shown to be inhibited by various oxidizing sulfhydryl reagents. It is also sufficiently inhibited by Cl to account for the observed bactericidal effect. Other loci of action of chlorine through a similar mechanism must also be assumed in view of the non-specificity of sulfhydryl inhibitions.