The filamentous cyanobacterium Anabaena variabilis ATCC 29413 fixes nitrogen under
aerobic conditions in specialized cells called heterocysts that form in response to an …

The nitrogenase gene cluster in cyanobacteria has been thought to comprise multiple
operons; however, in Anabaena variabilis, the promoter for the first gene in the cluster, nifB1 …

Anabaena variabilis ATCC 29413 is a filamentous heterocystous cyanobacterium that fixes
nitrogen under a variety of environmental conditions. Under aerobic growth conditions …

The cyanobacterium Anabaena variabilis has two Mo‐nitrogenases that function under
different environmental conditions in different cell types. The heterocyst‐specific nitrogenase …

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of
the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo …

In many filamentous cyanobacteria nitrogen fixation occurs in differentiated cells called
heterocysts. Filamentous strains that do not form heterocysts may fix nitrogen in vegetative …

Heterocysts are terminally differentiated cells of some filamentous cyanobacteria that fix
nitrogen for the entire filament under oxic growth conditions. Anabaena variabilis ATCC …

The exact identity of cyanobacteria that have been cultured from symbiotic associations with
the water fern Azolla spp., whether they are required in the symbiotic process, and their …

Some cyanobacteria are able to reduce atmospheric dinitrogen to ammonia—a process
where oxygen evolved by photosynthetic activity in the same cell is detrimental to nitrogen …

For over 50 years scientists have considered the possibility of engineering a plant with
nitrogen fixation capability, freeing farmers from their dependence on nitrogen fertilizers …