Factors Underlying Bacterial Enzyme Synthesis.

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Abstract
A marked stimulation of synthesis of formic hydrogenlyase by E. coli in the presence of Na formate and peptone is brought about by the addition of either DL-aspartate, fumarate or nitrate under conditions when little or no proliferation takes place. Addition of succinate, however, produces no effect. None of these compounds stimulates activity of the enzyme in pre-adapted cells. While a mixture of glycerol and peptone, or a mixture of fumarate and peptone does not secure enzyme synthesis, a mixture of glycerol, fumarate and peptone is effective. The energy for enzyme sythesis in resting cells may thus be obtained by the interaction of suitable H-donors and H-acceptors. Aspartate is effective because it is converted by aspartase into fumarate. This conclusion is supported by the fact that presence of ammonium ions inhibits the adaptation in a formate-peptone medium, but not in a glucose-amino acid medium where energy is secured by breakdown of glucose. Certain amino acids are required for enzyme synthesis, the most effective being leucine, aspartate, histidine and serine. Requirements for specific amino acids appear to vary with the strain of the organisms.