Date of this Version
Fatty acids and other surface active agents were used to clarify the relationship of surface activity to the inhibition of lactic streptococci. There was complete inhibition of lactic streptococci in media where surface activity exceeded a critical level. The effectiveness of inhibition by fatty acids, nonionic surface active agents, anionic surface active agents, decyl alcohol, growth medium, and temperature variation was directly related to the surface activity. The surface active agents created an unfavorable environment at most concentrations, rather than acting as a specific inhibitory substance to which the organisms were capable of adapting and thereafter resuming normal growth. The variety of chemical compounds and conditions that produce a common physical effect indicate the inhibition involves physical phenomena at the bacterium:menstruum interface. Results indicate that surfactants are important in the inhibition of lactic streptococci.