Some theoretical considerations on overflow production of metabolites

The overflow production of metabolites appears to be an energy spilling process in terms of life because part of the energy of the primary substrate remains in the metabolite produced. The other part of energy, which is liberated as reducing equivalents and/or ATP along the way to the product, must be wasted. This part is discussed to be responsible for the discrepancies between the theoretically possible and experimentally obtained product yields, because for the wasting process substrate or product are consumed. By reducing the amount of this superfluous energy the product yield should be increased. The auxiliary substrate concept occurs to be an appropriate method.