Represses biofilm formation in M9C glu and LB glu media but not in M9C and LB media. Seems to act as a global regulator of several genes involved in catabolite repression and stress response and regulation of the uptake and export of signaling pathways. Could be involved the regulation of indole as well as uptake and export of AI-2 through a cAMP-dependent pathway. After 3 hrs of cold shock. Cells show increased biofilm formation when glucose is present in the medium. In a continuous-flow system with M9C medium supplemented with glucose, the biofilm had a 240-fold greater biomass, a 2800 fold-greater average thickness and a 16-fold increased surface coverage than the wild-type.