in two out of three pleiotropic mutants of rhizobium meliloti , defective in nitrate reductase induced by amino acid utilization in vegetative bacteria and in symbiotic nitrogen fixation , nitrogenase activity could be restored completely by purines and partially by the amino acids l-glutamate , l-aspartate , l-glutamine , and l-asparagine .
C0002520
amino acids
C0017797
l-glutamine