Open AccessNitrite metabolism in the cyanobacterium Anabaena cycadeae : Regulation of nitrite uptake and nitrite reductase by ammonia
Author(s) -
Singh Surendra
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb05523.x
Subject(s) - nitrite reductase , nitrite , glutamine synthetase , biochemistry , glutamine , auxotrophy , glutamate synthase , chemistry , nitrate reductase , ammonia , metabolism , nitrate , enzyme , mutant , amino acid , organic chemistry , gene
Nitrogen regulation of nitrite uptake and nitrite reductase was studied in the cyanobacterium Anabaena cycadeae and its glutamine‐auxotrophic mutant. The development of the nitrite‐uptake system preceded, and was independent of, the development of nitrate reductase. The levels of both of the systems were higher in the glutamine auxotroph lacking glutamine synthetase (GS) than in the wild‐type strain having normal GS activity. The nitrite‐uptake system was found to be constitutive and ammonia‐repressible whereas the nitrite‐reductase system was ammonia‐repressible and nitrite‐inducible. Ammonia did not inhibit the nitrite‐uptake and nitrite reductase activities in the glutamine auxotroph whereas glutamine did so, suggesting that repression of nitrite‐uptake and nitrite reductase systems by ammonia requires the operation of GS and probably involves the participation of some organic nitrogen metabolites like glutamine.