Glucose-mediated catabolite repression of the tricarboxylic acid cycle as an explanation for increased acetic acid production in suicidal Aeromonas strains.

Growth in the presence of glucose, even under highly aerobic conditions, significantly reduced the activities of three tricarboxylic acid cycle enzymes, citrate synthetase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase, in suicidal but not nonsuicidal Aeromonas strains. Pyruvate dehydrogenase activity, however, was significantly increased. The activities of all of the enzymes, as well as the glucose-mediated increase in acetic acid production, were shown to be regulated by catabolite repression. The regulator protein is the same one which regulates the utilization of several sugars.