Itrogen cycles in each of these environments where they modify their morphology, metabolism, and light-harvesting systems for survival in their respective niches. To date, genomes of 55 cyanobacterial strains in 21 genera have been completed or are under construction (National Center for Biotechnology Information). These cyanobacterial genomes are diverse in size, ranging from 1.66 to 9.1 Mbp. The