Nitric oxide (NO) can induce the di

Nitric oxide (NO) can induce the dispersion of P. aeruginosa biofilms [12] and does so through the modulation of c-di-GMP levels without being biocidal. We showed that at 3 mM CAD, which is not growth inhibitory, the expression of c-di-GMP after 5 h was reduced by 66.2 % compared to the untreated control. Similarly, ginger extract reduced the expression of c-di-GMP and the biofilm formation of P. aeruginosa [35]. What remains to be explored is the molecular mechanism by which CAD mediates changes in c-di-GMP. For example, NO exposure can been linked to changes in c-di-GMP by modulating phosphodiesterase activity, which degrades c-di-GMP, leading to dispersal in P. aeruginosa [16]. In Vibrio harveyi, a membrane-bound receptor H-NOX/HqsK binds to and translates the recognition of NO to the quorum-sensing system to modulate biofilm formation [45].