On the efficiency of catabolism at the cellular level

The major focus of this work is on the understanding and manipulation of the energetic efficiency of growth of E. coli in glucose limited continuous culture, and in glucose excess batch cultures. The presence and absence of oxygen as the signaling molecule for the availability of an external electron acceptor strongly affects the energetic efficiency of cellular metabolism, thus making the study and manipulation of respiratory electron transport en E. coli, important from the research point of view, in order to optimize the biotechnological processes for the production of reduced biochemical products and the efficient growth of large-scale cultures. This thesis project deals with the functional characterization of various components of the respiratory chain of Escherichia coli which consists of various dehydrogenases, three quinone pools, several reductases and three cyctochrome oxidases. The role of these components in metabolic regulation under conditions of variable oxygen supply has been investigated in detail.