ANAEROBIC GROWTH OF SALMONELLA-TYPHIMURIUM ON L(-TARTRATE AND D(-)-TARTRATE INVOLVES AN OXALOACETATE DECARBOXYLASE NA+ PUMP())

We show here that the Enterobacterium Salmonella typhimurium LT2 has t he capacity to grow anaerobically on L(+)- or D(-)-tartrate as sole ca rbon and energy source. Growth on these substrates was Na+-dependent a nd involved the L(t-)- or D(-)-tartrate-inducible expression of oxaloa cetate decarboxylase. The induced decarboxylase was closely related to the oxaloacetate decarboxylase Na+ pump of Klebsiella pneumorzine as shown by the sensitivity towards avidin, the location in the cytoplasm ic membrane, activation by Na+ ions, and Western blot analysis with an tiserum raised against the K. pneumoniae oxaloacetate decarboxylase. P articipation of an oxaloacetate decarboxylase Na+ pump in L(+)-tartrat e degradation by S. typhimurium is in accord with results from DNA ana lyses. The deduced protein sequence of the open reading frame identifi ed upstream of the recently sequenced oxaloacetate decarboxylase genes is clearly homologous with the beta-subunit of L-tartrate dehydratase from Escherichia coli. Southern blot analysis with S. typhimurium chr omosomal DNA indicated the presence of probably more than one gene for oxaloacetate decarboxylase.