The role of carbon dioxide in the regulation of bacterial adaptive proliferation

The adaptive proliferation of bacteria or cell division in the absence of an exogenous organic substrate is controlled by density-dependent mechanisms with the participation of AHL- and AI-2-dependent quorum sensing systems. Along with the signaling molecules of these bacterial communication systems, bacterial metabolites that are permanently released during microbial metabolism, for example, CO2, can also participate in regulation and can serve as biomarkers of cell density. It has been established that carbon dioxide is necessary for the adaptive proliferation launch, and the increased content of atmospheric CO2 causes a premature stop to this process. Thus, CO2 is able to regulate the adaptive reactions of bacteria, including, probably, being one of the signals involved in the initiation and termination of the process of adaptive proliferation. It has been shown that CO2 in the form of the bicarbonate ion HCO3- can activate the cAMP-dependent signaling cascade and is also included in the bacterial cell mass.