[The effect of composition and ionic strength of external solution on the aspartate-ammonia lyase and fumarate hydratase activity in Escherichia coli cells].

It was found that the nonspecific effect of ionic strength of the external solution on the enzymatic activity of E. coli cells consists in rapid changes in the permeability of cell membranes interacting with the substrate. This effect depends on the initial substrate concentration, i.e., ionic strength of the external solution, and is maintained for some time as the substrate concentration decreases. Chloramphenicol, a protein synthesis inhibitor, and sodium azide, a respiration inhibitor (300 micrograms/ml and 200 microM, respectively) do not change the enzymatic activity of E. coli cells during the synthesis of L-aspartic and L-malic acids from fumaric acid. The kinetic equations of L-aspartate and L-malate synthesis are described by equations of zero and intermediate (between zero and first) order, respectively.