The role of high electrolyte concentration in the production and growth of L forms of bacteria.

It has been reported that certain strains of ,B hemolytic streptococci produce L type colonies if they are exposed to penicillin on media containing high concentrations of non-toxic salts (Sharp, 1954). No such colonies developed without increased salt concentration. Following this observation a number of strains of several other bacterial species were studied to test the effect of variation of the salt concentration of the media. During these studies L type colonies were observed for the first time in staphylococci and diphtheroids; a number of strains of a hemolytic streptococci produced L colonies with increased salt in the media, whereas previously only a very few strains had been found to do so, and L forms of the colon bacillus were obtained in large colonies which grew in sufficient abundance to permit subculture. High salt concentrations exerted no influence on the development of L type colonies in a number of other species in which such colonies have been observed on the usual media.