Effect of nutritional deficiencies on synthesis of the inducible malic enzyme of lactobacillus plantarum

Summary

The reduction of synthesis of the inducible malic enzyme by cell suspensions of biotin-deficient Lactobacillus plantarum 17-5 is also shared by cells deficient in nicotinic acid, thiamine, and pyridoxine. Addition of the deficient vitamin at the start of enzyme synthesis increases the amount of enzyme formed.

Suspensions of riboflavin-deficient cells also synthesize a reduced amount of enzyme but addition of riboflavin does not increase enzyme synthesis. Suspensions of pantothenate-deficient cells either show a small reduction or a small stimulation of malic enzyme synthesis. Suspensions of p-amino benzoic acid (PAB)-deficient cells synthesize greater than normal amounts of malic enzyme.

A more detailed comparison of differences between malic enzyme synthesis by normal and by PAB-deficient cells show that chloramphenicol is more inhibitive to enzyme synthesis by normal cells and that chlorpromazine is more inhibitive to enzyme synthesis by PAB-deficient cells. Possible explanations of the results with inhibitors are discussed.

Cells deficient in adenine, act similarly to PAB-deficient cells with respect to amount of enzyme synthesized and effect of inhibitors. The amount of enzyme synthesized and the effect of inhibitors on the adenine-deficient cells is changed to a pattern resembling that of normal cells when adenine is added at the beginning of enzyme synthesis. An interpretation of these results is offered.