[Effect of a beryllium complex on growth of Pseudomonas fluorescens (types R and S). I. Influence on the lag phase]

The toxicity of beryllium for Pseudomonas fluorescens is studied with the aid of an anionic complex of the element which is stable in peptone medium at pH 6 during the period of investigation. The toxic effect is characterized by an increase in the lag phase which is proportional to the square of the beryllium concentration. Further, a process of progressive adaptation is observed when the concentration of the beryllium complex is gradually increased.