Biochemical response of continuous-flow activated sludge processes to qualitative shock loadings.

Abstract

Considerable effort is being ex pended in the basic biological sciences regarding control mechanisms in meta bolic processes. Our recent investiga tions indicate that one manifestation of the operation of such control mech anisms, sequential substrate removal, also occurs in heterogeneous popula tions, and that these mechanisms are affected by the physiological condition of the sludge (1) (2). The control mechanisms known to operate in meta bolic processes have been reviewed re cently by the authors (3). Briefly, two types of mechanisms generally are cited as the major con trols which regulate the flow of metab olites through biochemical pathways. These mechanisms usually are referred to as repression and feedback in hibition ' '. Repression is defined as the mechanism which controls the flow of metabolites through a pathway by de creasing the rate of enzyme synthesis which otherwise would lead to an over production of end products as well as temporarily unnecessary enzymes. Feedback inhibition is the control mechanism which exerts its influence by inhibiting the function or the ac tivity of an enzyme in a biosynthetic