Action of Penicillin in Preventing the Assimilation of Glutamic Acid by Staphylococcus Aureus

Abstract

CERTAIN bacteria possess the ability to assimilate (glutaimc acid and to concentrate this amino-acid in the free state within the internal environment¹. Glutamic acid cannot pass through the bacterial cell-wall by free diffusion as the migration requires energy whigh can be supplied by exergonic metabolism such as the fermentation of glucose by the organism. At equilibrium the concentration of glutamic acid in the internal environment is markedly greater than that holding in the external environment. Since a survey of a large number of bacterial species has shown that this capacity to assimilate and concentrate glutamic acid is restricted to Gram-positive organisms², it was decided to investigate the action on the assimilatory process of various chemotherapeutic agents which are known to differentiate between Gram-positive and Gram-negative bacteria.