Abstract

Cyanobacteria are distributed worldwide, and considered beneficial or harmful to the aquatic environment, due participation in the nitrogen cycle and to the production of secondary metabolities with toxic effects to other species. Therefore, the quality of aquatic environmentsshould be monitored in physical, chemical and biological aspects. The aim of this study was to analyse the cyanobacteria presence and diversity from samples of freshwater used for irrigation of a vegetable planting area which are used for animal feed that belongs to the farm of the Foundation Zoological Park of Sao Paulo thorough metagenomics approaches. The results were obtained by the total environment DNA sequencing and subsequent analysis by MG-RAST and statistical tools. The taxonomic classification study shows the presence of 72 species of Cyanobacteria. Among the most abundant highlight Dolichospermum macrosporum, Dolichospermum crassum and Microcystis aeruginosa, which are related with bloom and production cyanotoxins. However, there was not observed evidence of cyanobacteria bloom into the water, but there are a population of these organisms in the studied samples. Considering the freshwater use in the area food production this study indicated that the cyanobacteria population found in the irrigation water should be monitored to avoid toxic effects to the food produced in the area and the environment itself.