Open AccessShort‐term effect of ammonia on nitrogenase activity of Anabaena variabilis (ATCC29413)
Author(s) -
Reich Sabine,
Almon Helmar,
Böger Peter
Publication year - 1986
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.1574-6968.1986.tb01347.x
Subject(s) - anabaena variabilis , nitrogenase , ammonia , glutamine synthetase , biochemistry , glutamine , anabaena , chemistry , nitrogen fixation , biology , cyanobacteria , bacteria , nitrogen , amino acid , organic chemistry , genetics
Intact filaments of the cyanobacterium Anabaena variabilis switch off nitrogenase activity very rapidly upon addition of NH 4 Cl when incubated in an alkaline environment (pH 10.0) permitting a fast NH 3 ‐influx into the cells. When assayed in cell‐free extracts (prepared from ammonia‐treated filaments), nitrogenase remains inhibited in the presence of an ATP‐regenerating system. Furthermore, l ‐methionine‐ d,l ‐sulfoximine, an inhibitor of glutamine synthetase, added to the filaments, prevents inactivation of nitrogenase by ammonia, showing that ammonia is not the compound directly responsible for nitrogenase switch‐off.