The Influence of Cations Upon Bacterial Viability

Abstract

A comparative review of a number of earlier investigations showing that all cations in low conc. tend to stimulate bacterial growth and development, while in stronger conc. they exert a reverse effect. The relative influence of the individual cations is approximately the same both in the stimulating and inhibitive zones and may be expressed in a single figure of "specific potency." These specific potencies are generally parallel with the position of the cations in the E.M.F. series. The favorable effect of low concs. appears to be associated with increased diffusion through the cell wall, the inhibitive action with decreased diffusion, and a relationship is suggested between these effects and Bancroft''s observations on coagulation of cell colloids. The anions appear to exert their influence mainly through the medium of hydrogen ion concentration. The author urges that in studies of certain biological phenomena the possibility of specific potency effects should be taken into account before assuming salt antagonism or other specific qualitative influences.