Anaplerotic Sequences in Microbial Metabolism

In addition to catabolic and anabolic pathways, which enable nutrients to enter and to be withdrawn from the central routes of metabolism, enzymic sequences operate to ensure that intermediates, removed from these central routes in the course of biosynthesis, are replenished. These obligatory pathways of replenishment are generically designated “anaplerotic sequences”. The nature of these sequences, operative in micro‐organisms growing on C 3 ‐ and C 2 ‐compounds, is discussed in outline, and the mode of regulation of one of them (the glyoxylate cycle) is examined in detail.