Carbon catabolite repression (CCR) is a global regulatory mechanism that inhibits the expression and activities of functions for the use of secondary carbon sources when a preferred carbon source is present. This allows bacteria to selectively use substrates from a mixture of different carbon sources.

Is Catabolite a repression?

Carbon catabolite repression (CCR) is a regulatory mechanism by which the expression of genes required for the utilization of secondary sources of carbon is prevented by the presence of a preferred substrate.

Why do microbial cells undergo catabolite repression?

Carbon catabolite repression (CCR) is an important regulatory mechanism in bacteria that ensures that the cell relies on its preferred substrates to achieve optimal growth [1]. ... These data suggest that substrate uptake and cell growth relates to macromolecular crowding and that CCR enables optimal cell growth.