Ammonium ion-excreting cyanobacterial mutant as a source of nitrogen for growth of rice: A feasibility study

Summary Growth of rice plants in a nitrogen-free medium was enhanced by inoculation with a nitrogenase-derepressed mutant (strain SA-1) of a cyanobacterium,Anabaenavariabilis which excretes NH₄⁺ into the medium. Both total dry weight and nitrogen content of rice plants were substantially increased in the presence of the mutant strain but not with the wild type parent, strain SA-0.