Involvement of Coenzyme A Esters in the Metabolism of Benzoate and Cyclohexanecarboxylate by Rhodopseudomonas palustris

Abstract

Rhodopseudomonas palustris was grown on benzoate, cyclohexanecarboxylate or succinate under anaerobic or aerobic conditions. Studies of oxygen uptake by intact bacteria indicated that cyclohexanecarboxylate was metabolized aerobically by a β-oxidation sequence and that cultures grown anaerobically on benzoate also possessed this capacity. Bacteria grown on succinate were able to oxidize octanoate but not alicyclic acids. The enzymes necessary for the β-oxidation of cyclohexanecarboxylate appeared to be constitutive in both anaerobic and aerobic bacteria, the only exception being an acyl-CoA synthetase which used benzoate and some alicyclic acids as substrates. This acyl-CoA synthetase differed from the constitutive short-chain fatty acyl-CoA synthetase in that it was induced by anaerobic growth on benzoate or by aerobic growth on cyclohexanecarboxylate.