Two unicellular nitrogen fixing cyanobacteria were isolated from the coastal waters outside of Zanzibar, Indian Ocean. Genomes from both strains were sequenced using Illumina Miseq and compared to other unicellular diazotrophs.. Unicellular diazotrophic cyanobacteria SU2

Unicellular cyanobacteria are important players in the nitrogen cycle of the marine environment. Majority of strains available to date have been isolated from the Atlantic and the Pacific Oceans. This study isolated two new strains of nitrogen fixing cyanobacteria from the coastal waters outside Zanzibar in the Indian Ocean. The genomes of both strains have been sequenced using Illumina miseq, assembled and annotated. Genomes were compared to other unicellular cyanobacteria and SU2 was found to be most closely related to Cyanothece PCC8801 and Crocosphaera watsonii. Nitrogen fixation experiments showed a clear temporal separation with oxygenic photosynthesis of which the former occurred exclusively during the hours of darkness.