[The inhibition of post-exponential growth in "Saccharomyces cerevisiae" by L-lysine (author's transl)].

The inhibitory effect of L-lysine upon the post-exponential growth of Saccharomyces cerevisiae has been previously demonstrated and the present report extends the observation. During the post exponential phase, the cells do not divide but the cell mass normally increases two or three-fold; in the presence of exogenous lysine this increase is considerably reduced, bud growth is blocked and the cytological features of the post-exponential cells are considerably modified. The effect is apparent in liquid as well as on solid media. L-alpha-aminoadipate, being a precursor of L-lysine, exerts a similar effect since the exponential phase. Mutants resistant to the effect of lysine proved to be permeability mutants. The phenomenon is not restricted to any one strain of S. cerevisiae but characterized all strains of the species which are unable to catabolize lysine.