Bacterial permeability; total uptake of lysine by intact cells, protoplasts, and cell walls of Micrococcus lysodeikticus.

A preceding study has shown that the pooled uptake and retention of lysine occurs equally or greater in protoplasts than in intact cells of Micrococcus lysodeikticus (Britt and Gerhardt, 1958). In the course of these analyses, it was noted that the intact cells apparently contained considerably more lysine than that found in the free amino acid pool. In the series of experiments to be reported here, we sought to relate more quantitatively the lysine entry into the internal pool with the total uptake by the cell, and also to determine where and how in the cell structure this larger, nonpooled balance of lysine uptake was localized. The latter aim was approached by comparing the total uptake and release of lysine by masses of intact cells, protoplasts, and isolated cell walls of the organism.