Changes in the energy indices of Escherichia coli during exhaustion and renewal of glucose and ammonia supply as a factor responsible for the coupling of energy and constructive types of metabolism

The shift down of glucose in the growth medium lowered the energetic status of cells whereas that of ammonium elevated it, which was indicative of their specific effect on metabolism. The shift up of glucose within the first four seconds promptly increased the intracellular ATP pool, the energy charge and the ATP/ADP ratio up to values characteristic of growth, while the addition of ammonium after its exhaustion resulted in the opposite effect. The described changes are typical of an incomplete coupling between energetic and constructive metabolic types in E. coli.