Metagenomic Analysis of Cyanobacteria in an Oligotrophic Tropical Estuary, South Atlantic

• Published in: Frontiers in microbiology 2018-06, Vol.9, p.1393-1393
• Main Authors: Affe, Helen M de Jesus, Rigonato, Janaina, Nunes, José M de Castro, Menezes, Mariângela
• Format: Article
• Language: English
• Subjects: Camamu Bay; functional profile; Life Sciences; marine cyanobacteria; metagenomic diversity; Microbiology; shotgun
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2018.01393

This study assessed the species composition, distribution, and functional profiles of cyanobacteria in Camamu Bay, a tropical oligotrophic estuarine system on the northeast coast of Brazil, using shotgun metagenomic sequencing. Surface-water samples were evaluated in two different rainfall periods (rainy and dry seasons), at nine stations in the three hydrodynamic regions of the bay. At a fixed sampling station, on each season, samples were taken over a tidal cycle at 3-h intervals over 12 h. A total of 219 cyanobacterial taxa were identified, demonstrating a diverse community of freshwater, euryhaline, and marine cyanobacteria. The genera of greater relative abundance, and , corresponded to the picoplankton fraction. Although Camamu Bay has conspicuous marine characteristics, the contribution of freshwater during the rainy season caused variation in cyanobacteria community, with an increase in species richness. Due the high prevalence of (90% of the sequences), the functional analysis revealed only minor differences in gene content between the dry and rainy seasons. In both rainy and dry seasons, an increase in relative abundance occurred during high tide, demonstrating the tidal influence in the bay. The environmental characteristics of the bay provide niche conditions for a wide variety of cyanobacteria, including freshwater, euryhaline, and marine strains.