The repression of some bacterial enzymes by the presence of glucose in the growth medium. Depression of cyclic AMP levels due to the availability of glucose is mediated by inhibition of adenylate cyclase by a glucose catabolite. In the absence of glucose, a complex between cyclic AMP and its binding protein attaches to specific regions of DNA and activates transcription. Cyclic AMP acts as a starvation signal, as it does in animal cells, but in bacteria it acts at the transcriptional level.