INTRACELLULAR CONCENTRATIONS OF COENZYME A AND ITS DERIVATIVES FROM CLOSTRIDIUM-ACETOBUTYLICUM ATCC-824 AND THEIR ROLES IN ENZYME REGULATION

Intracellular levels of coenzyme A (CoA) and its derivatives involved in the metabolic pathways for Clostridium acetobutylicum ATCC 824 were analyzed by using reverse-phase high-performance liquid chromatograph y (HPLC). During the shift from the acidogenic to the solventogenic or stationary growth phase, the concentration of butyryl-CoA increased r apidly and the concentrations of free CoA and acetyl-CoA decreased. Th ese changes were accompanied by a rapid increase of the solvent pathwa y enzyme activity and a decrease of the acid pathway enzyme activity. Assays with several non-solvent-producing mutant strains were also car ried out. Upon entry of the mutant strains to the stationary phase, th e butyryl-CoA concentrations for these mutant strains were comparable to those for the wild type even though the mutants were deficient in s olvent-producing enzymes. Levels of acetoacetyl-CoA, beta-hydroxy-buty ryl-CoA, and crotonyl-CoA compounds in both wild-type and mutant extra cts were below HPLC detection thresholds (<21 muM).