Studies on the Action of Wetting Agents on Microörganisms

Abstract

The germicidal action of phenol in buffered alkaline solns. with or without wetting agents was detd. using Staphylococcus aureus (Insecticide Board strain) as test organism. The germicidal action of phenol decreases as the phenol is progressively neutralized, and at 25[degree]C, the germicidal power of a buffered phenol soln. is detd. primarily by the conc. of undissociated phenol present. The effect of addition of various wetting agents to buffered alkaline phenol solns. was detd. In general there was a pronounced increase in the germicidal action of the soln. provided the pH was rigidly controlled. The effect was a function of the conc. as well as nature of the wetting agent. The germicidal action of solns. containing buffer, phenol and wetting agents decreases with increase in alkalinity from pH 9 to pH 11 although the germicidal action of solns. of buffer and wetting agents increases in the same range. This indicates that the presence of the wetting agent enhances the action of the undissociated phenol more than that of the phenolate.