FICOCIANINA COMO INDICADOR DE CIANOBACTÉRIAS EM RESERVATÓRIOS

Abstract

PHYCOCYANIN AS AN INDICATOR OF CYANBACTERIA IN RESERVOIRS. Phycocyanin is a pigment present in cyanobacteria whose optical characteristics favor its application in clinical, dietary, and environmental aspects. There are reports of studies of these pigments in lakes and reservoirs, which present different analysis methodologies. Based on this information, this work aims to evaluate correlations between phycocyanin and the number of cyanobacteria to optime the methodologies mentioned above. The samples were collected from four reservoirs in the semiarid region of Ceará, and the applied methodology was based on the work of Hórvath (2013). The spectrophotometry and the fluorimetry analyzes were performed in this analysis. The analytical curves for the phycocyanin showed high linearity, and the fluorimetric technique, which was used due to its greater analytical sensitivity. The absorbance coefficient (2.57 mL mg-1 cm-1) was obtained by spectrophotometry, which was lower than that reported in the literature. The correlations found were higher and significant for phycocyanin (r > 0.70) for the reservoirs, while the correlations with chlorophyll were much lower, hence is contrary to what was observed in the literature. It is concluded that the phycocyanin pigment should be used as an indicator in the estimation of cyanobacteria in reservoirs, replacing the use of chlorophyll for the same function.