Comparative Genome Analysis of Phormidesmis priestleyi ULC007 and Some Representatives of Genus Phormidium (Cyanobacteria)

Cyanobacteria live in a wide range of habitats encompassing freshwater, marine, and terrestrial ecosystems. They are one of the most morphologically diverse groups. Techniques based on polyphasic taxonomy were introduced to cyanobacterial systematics in an attempt to overcome the shortcomings brought by the traditional emphasis on morphological features. Recent advances in genomics are greatly accelerating our understanding of cyanobacterial taxonomy. Genomes available in NCBI's GenBank were selected to comprehensively clarify the genetic similarities and differences of representatives of genus Phormidium and Phormidesmis priestleyi ULC007 (former Phormidium priestleyi). We performed a comparative genomic analysis, which includes analysis of genome characteristics and annotation of the subsystem, classification of functionally annotated common genes and automatic annotation of secondary metabolic gene clusters. Results showed that about 83% of the genes in the studied cyanobacterial genomes were identified as genes with unknown functions, and those with annotated functions were mainly involved in: (I) cofactors, vitamins, prosthetic groups, and pigments; (II) cell wall and capsule; (III) RNA metabolism; (IV) protein metabolism; (V) DNA metabolism, (VI) fatty acids, lipids, and isoprenoids; (VII) respiration; (VIII) stress response; (IX) amino acids and derivatives; and (X) carbohydrates We found that Phormidesmis priestleyi ULC007 possess seven genes involved in the chemotaxis. The in silico identification, annotation and analysis of the secondary metabolite biosynthesis gene clusters of the most promising targets within the studied cyanobacterial genomes showed presence of specific secondary metabolite genes, which need further detailed analyses.