Seven species of cyanobacteria from the reservoirs of Sítios Novos and Gavião, both located in Ceará and maintained in the collection of Laboratory of Quality and Water Treatment of the Federal University of Ceará were molecularly characterized based on DNA markers aiming at your identification. The molecular characterization of the seven strains was performed and the sequencing of the 16S rRNA and the cpcBA locus sequencing were performed for identification at the genus level and to generate a phylogenetic tree. In the BLAST analysis, the sequences showed bootstrap value (grouping confidence) from 53 to 100% as compared to other known sequences of cyanobacteria deposited in GenBank. Phylogenetic analysis identified three orders of cyanobacteria: Chroococcales (n = 1), Oscillatoriales (n = 2) and Nostocales (n = 4), among them the genera identified were Microcystis, Planktothrix and Raphidiopsis, respectively. Morphological and molecular data were in agreement to the genus level for 85% of the isolates obtained (6/7). With this, it can be concluded that the use of the cpcBA locus is still seen as the best to be used because it is a specific marker for cyanobacteria. The polyphase approach is still currently a more reliable option for the identification of cyanobacteria.

Keywords: 16SrDNA; locus cpcBA; DNA markers; Cyanobacteria; Identification