The regulation of some enzymes involved in ammonia assimilation by Rhizobium japonicum.

The concentrations of three enzymes active in ammonia assimilation by Rhizobium japonicum (glutamate dehydrogenase, aspartate aminotransferase, alanine aminotransferase) were influenced considerably by the N-source in the culture medium. Relatively high concentrations of these enzymes were present when R. japonicum was grown in a medium containing NH,CI+ 2-oxoglutarate. Relatively low amounts of these enzymes were found in bacteria grown in the presence of various amino acids. Active protein and RNA synthesis were necessary for the induction of the enzymes by NH,CI+ 2-oxoglutarate.