metabolic adjustment in bacteria such as E. coli that allow them to metabolize glucose before other nutrients. Once the glucose in the mediais depleted, genes for the catabolism of other nutrients are induced. The system is based on the levels of cylic AMP in cells.

The repression of transcription of the components of a biosynthetic pathway due to the accumulation of the degradation products of the metabolite produced by the pathway.

Repression of a variety of unrelated enzymes when cells are grown in a medium containing a specific substrate. See diauxy.