Cadmium mediated control of nitrogenase activity and other enzymes in a nitrogen fixing cyanobacterium.
Cadmium decreased the specific growth rate and total cell mass at concentrations > 0.001 micrograms ml-1. It also reduced heterocyst frequency, total cell protein, nitrogenase activity (acetylene reduction) and decreased glutamine synthetase (GS) and glutamate synthase (GOGAT) activities. However, cells grown under low concentration of cadmium (0.001 microgram ml-1) had enhanced nitrogenase as well as GS activity besides showing increased growth rate and heterocyst frequency. Cadmium has apparently controlled nitrogenase activity and nitrogen fixation possibly via mediating enzymes including glutamine synthetase in Nostoc muscorum.
Trehan
K
K
Department of Botany, Kurukshetra University, India.
Maneesha
D002104:Cadmium / Q000494:pharmacology*; D000458:Cyanobacteria / Q000201:enzymology* / Q000254:growth & development; D005970:Glutamate Synthase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D009586:Nitrogen Fixation / Q000187:drug effects*; D009591:Nitrogenase / Q000378:metabolism*
D002104:Cadmium; D009591:Nitrogenase; D005970:Glutamate Synthase; D005974:Glutamate-Ammonia Ligase