THE ROLE OF HIGH ELECTROLYTE CONCENTRATION IN THE PRODUCTION AND GROWTH OF L FORMS OF BACTERIA,

Abstract

Concentrations of NaCl above 0.26 M in otherwise appropriate media make possible the isolation of L colonies from Group A streptococci, staphylococci and diphtheroids. An increase in the electrolyte concentration also makes possible isolation of L colonies from colon bacilli and from most strains of alpha hemolytic streptococci. High salt concentration is necessary in these cases to maintain growth in subculture and has made possible the cultivation of L forms of the streptococci in fluid media. All the non-toxic salts tested, including NaCl, NH4CI, KC1, CaCl2, MgCl2 and Na2HPO4 were effective in permitting isolation of L colonies from one or more strains of bacteria that require high concentrations of electrolyte for transformation to the L form. Li Cl and sub-inhibitory concentrations of several toxic salts did not permit production of L forms. Transition from bacterial into L forms was effected in all cases by penicillin. A definition of the term "L Forms" of bacteria is restated, since there has been considerable variation in its recent application.