Evaluación de la respuesta fisiológica de la microalga Chlorella sp. a la presencia de metal cromo (VI) en aguas sintéticas.

Abstract

Heavy metal as chromium are among the most toxic contaminants that affect the water resources due of the textile and tannery activities involve damage in the microalgae that shape the first links of the trophic chain. The present work evaluates the physiological response of the Chlorella sp. in the presence of chromium (VI) in synthetic waters. For this was quantified chlorophyll a, b and carotenoids for spectrophometers methods and the mortality percent through counts in Neubauer chamber, the microalgae was exposed to five concentrations of Cr (VI) in a period of 96 hours at pH 4, 6 and 8. The inhabitation synthesis of pigments and cellular death were determined for the concentrations higher than 15 mg/L of chromium meanwhile lower concentrations increase the cell density and pigments. The pH 4 affects Chlorella sp. with a mortality percent of 67 % whit a metal concentration to 60 mg/L while pH 6 and 8 had a mortality percent to 27 % and 17% respectively. The facts of pH and metal concentration have been fundamental since in an a extrapolation with 10x106 cell/mL it was observed that the physiology of microalgae was affected in pH 4 and 6 with less production of pigments and pH 8 was optimum for that Chlorella sp. can resist high concentrations of metal.