Oxidation of Carbon Sources through the Tricarboxylic Acid Cycle in Mycobacterium leprae Grown in Armadillo Liver

Abstract

Enzymes of the tricarboxylic acid (TCA) cycle were demonstrated in extracts of M. leprae grown in armadillo liver. Many were also present in homogenates of host tissue, but biochemical evidence was obtained which indicates that all enzymes detected in extracts from M. leprae were authentic bacterial enzymes. Further evidence for a complete TCA cycle in M. leprae was obtained by first establishing that citrate could be taken up and catabolized by whole M. leprae organisms, then showing that oxidation of radioisotopically labeled pyruvate to CO2 by suspensions of M. leprae was stimulated by adding unlabeled citrate. Control of TCA cycle activity in M. leprae by the inactivation of fumarase by a protease is speculated upon.