Succinate-mediated catabolite repression of enzymes of glucose metabolism in root-nodule bacteria
1993
Mandal, N.C. | Chakrabartty, P.K.
Enzymes of the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways were detected in strains of Rhizobium and Bradyrhizobium cultured on glucose. The enzymes, except glyceraldehyde-3-phosphate dehydrogenase, were present only in trace amounts in succinate-grown cells. The enzymes of the pentose phosphate pathway, being absent in Bradyrhizobium, were detected only in glucose-grown cells of Rhizobium. The presence of the glucose-catabolic enzymes in cells only during growth on glucose suggests that they are inducible in nature. Succinate repressed the glucose catabolic enzymes, and the repression appeared to be similar to catabolite repression. Exogenous addition of cAMP caused no change in the activity of these enzymes, demonstrating that the repression was unlikely to be mediated via cAMP.
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