Construction of an Escherichia coli strain which excretes abnormally large amounts of adenosine 3',5'-cyclic monophosphate.

It has previously been shown that an Escherichia coli CRP- strain 5333 accumulates abnormally large amounts of adenosine 3',5'-cyclic monophosphate (cAMP). Using P1 transduction, the CRP- character was transferred to E. coli Crookes strain which is deficient for cAMP phophodiesterase (CPD-). The resulting strain HY22 (CRP-, CPD-) accumulates greater amounts of cAMP both intracellularly and extracellularly than does 5333. In glucose minimal medium, an HY22 cell accumulates 100 times more cAMP intracellularly and excretes cAMP 150 times faster than does a wild-type E. coli cell.