title: Regulation of glutamate dehydrogenase activity and ammonia production in a nitrogen fixing cyanobacterium.
abstract: A glutamate auxotroph was obtained in Nostoc muscorum by induced mutagenesis with nitrosoguanidine. The metabolic pathway leading to glutamate synthesis was traced by selecting several enzymes. The strain was found to be lacking glutamate dehydrogenase. Other enzymes, however, were normal in their activity including isocitric dehydrogenase, glutamine synthetase and glutamate synthase. Nitrogen metabolism of the auxotroph and wild type was compared. The strain released exceedingly high amounts of ammonium in the medium.
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000458:Cyanobacteria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D005970:Glutamate Synthase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation
chemical_list: D000641:Ammonia; D007521:Isocitrate Dehydrogenase; D005970:Glutamate Synthase; D005969:Glutamate Dehydrogenase; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen