Dissolved Cycllc Adenosine Monophosphate (CAMP) in the Sea and Uptake of CAMP by Marine Bacteria

Dissolved cyclic-3',5'-adenosine monophosphate (CAMP) was measured in coastal seawater. Concentrations of cAMP ranged from 1 to 35 X 10-'* M being greatest in nearshore surface samples and from early evening through early morning. Dissolved cAMP was rapidly taken up intact by natural populations of marine bacteria, evidently via high affinity transport systems. Much higher concentrations were found in sediments. Presumed sources of dissolved cAMP are planktonic organisms (bacteria, algae, zooplankton, etc.). cAMP was also measurable in the plankton. Uptake of cAMP from seawater apparently increases the intracellular concentration of cAMP in marine bacteria and thus may play a role in their metabolic regulation.