title: Glutamine synthetase specific activity and protein concentration in symbiotic Anabaena associated with Azolla caroliniana.
abstract: Glutamine synthetase (GS) is the primary NH4+ assimilating enzyme of cyanobacteria. The specific activities and cellular protein concentration of GS in symbiotic cyanobacteria associated with the water fern Azolla caroliniana were determined and compared to free-living cultures of Nostoc sp. strain 7801, a strain originally isolated from symbiotic association with the bryophyte Anthoceros punctatus. Both the in vitro specific activity and concentration of GS in symbiotic cyanobacteria separated from A. caroliniana were approximately 3-fold lower than the free-living Nostoc sp. strain 7801 culture. These results imply depressed synthesis of GS by the symbiont associated with A. caroliniana.
mesh_terms: D000458:Cyanobacteria / Q000201:enzymology*; D005974:Glutamate-Ammonia Ligase / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D010944:Plants / Q000378:metabolism*; D013559:Symbiosis
chemical_list: D005974:Glutamate-Ammonia Ligase