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

Abstract

Current hypotheses of the mode of bactericidal action of chlorine suppose a direct combination of some chemical 'species of the chlorine with the bacterial protoplasm producing a toxic organic complex (Porter, 1946). Although this view is a great advance over earlier concepts, it still lacks precision in terms of our present knowledge of the intermediary metabolism of cells. The marked efficiency of chlorine, exerting a bactericidal action in concentra-tions of 0.2 to 2.0 ppm in water, will at once classify it as a biologically active "trace substance. " It may consequently be assumed to exert its effect upon the enzyme systems of the cell (Green, 1941). By investigation of the effect of chlorine on bacteria and on various enzymes, its bactericidal effect has been shown to depend upon the inhibition of certain essential enzyme systems, and the mechanism of this inhibition involves the powerful oxidative action of chlorine on the-SH groups of these enzymes. METHODS Active chlorine was estimated by the acid-iodine thiosulfate titration procedure