Deciphering carbon catabolite repression in bacteria

Abstract

Carbon catabolite repression (CCR) is a common strategy adopted by microorganisms which preferentially select and metabolize one carbon source before uptaking another. This gives rise to the famous diauxic growth curves. Since Monod's experiments which brought this process to light 80 years ago, the field has developed significantly. Today, CCR is understood as strategy which avoids unnecessarily protein production needed for the metabolizing secondary carbon sources when a more favorable source is present but other theories start to emerge. Moreover, the molecular mechanism of CCR differs significantly between different bacterial groups and so do the preferred carbon sources. This review describes CCR in four bacterial groups and highlights the yet lingering questions remaining in the field.