Trichormus variabilis N2B Genome sequencing and assembly. Trichormus variabilis N2B

Anabaena variabilis N2B is a photosynthetic, nitrogen-fixing cyanobacterium that was isolated as a possible cyanobiont from the fresh-water fern Azolla caroliniana. This free-living, filamentous strain forms heterocysts in the absence of combined nitrogen and fixes nitrogen using one of three nitrogenase systems, Nif1, Nif2, or Vnf. A. variabilis N2B is chemoheterotrophic and can use sugars as a carbon source. A. variabilis N2B is nearly identical to Anabaena variabilis ATCC 29413 (NCBI:txid240292), a free-living strain that is capable of infecting the liverwort Blasia.