Biorremediação do azo corante Amarelo tartrazina por três espécies de microalgas Chlorophyta

Abstract

Dyes are an example of toxic compounds released into the environment by textile, cosmetics, and food industries, among others. Tartrazine, a yellow orange dye widely used in the food industry, is an azo compound with deleterious effects on human health and aquatic communities. The chapter 1 of this work presents a literature review about the toxicological effects of azo dyes in various organisms and the removal of these compounds by microorganisms. In chapter 2, we analyzed the growth and tartrazine removal capacity of three axenic strains of microalgae, namely Desmodesmus spinosus (Scenedesmaceae), Muriella decolor (Chlorellaceae), and an unidentified species of Chlamydomonadales. The experiment was performed in triplicate under three conditions, as follows: microalgae grown in culture medium only, microalgae grown in culture medium containing 70 mg L 1 tartrazine, and culture medium containing 70 mg L 1 tartrazine without algae. Growth and dye removal curves were determined by measuring the absorbance at 75 0 and 426 nm, respectively. Covariance analysis was used to compare the curves. Dye exposure did not affect ( p = 0.6) the growth of the Chlamydomonadales strain, which was able to remove 43% of tartrazine dye ( p = 0.004). M. decolor cultured in medium containing tartrazine achieved 28% dye removal ( p = 0.02); microalgal growth was not affected by the dye ( p = 0.4). D. spinosus also significantly decreased dye concentration ( p = 0.003), achieving 25% tartrazine removal and good growth in the presence of dye ( p = 0.6). This study demonstrated the potential of microalgae to remove tartrazine, a dye that has received limited scientific attention, from a stable system, maintaining unaffected growth for a minimum of 12 consecutive days.