Efecto de la Toxicidad de Metales Pesados en Chlorella Sp Proveniente de Fuentes Naturales de Agua Dulce Fase 1

General objective To study the effect of heavy metals on the development of Chlorella microalgae from natural freshwater sources, through analysis of their morphological development, pigment production and cell density to assess the consequences of cadmium, chromium and lead toxicity. Justification The different sources of fresh water in the Metropolitan District of Quito provide local communities with a number of valuable uses, irrigation being one of the most frequent. However, due to their proximity to urban and industrial areas, many sources also serve as a catchment basin for a variety of wastes or pollutants. Thus, the Machangara River has come to be considered practically dead (El Comercio, 2017) (Telégrafo, 2017). Among contaminants, metal ions are one of the most toxic and persistent in water. Several species of microalgae have been found to naturally develop resistance to a specific type of metal ion in water (Rai et al. 1981). This characteristic has served for the exploitation of the described microalgae in metal removal processes, such is the case of the research project that precedes this one “Removal of heavy metals with biomass of the microalgae Chlorella sp. immobilized on alginate beads. However, this is not the only use of this microalgae. Algal bioassays are routinely used as part of a battery of toxicity tests to assess the environmental impacts of pollutants in aquatic ecosystems, this is achieved by measuring the decrease in growth rate or final cell biomass after a period of exposure. specified. This is why it is imperative to know the behavior of Chlorella against heavy metal exposure, at the laboratory level (Genter, 1996) (Franklin, Stauber, Apte, & Lim, 2002). Additionally, it should be noted that Chlorella, thanks to the photosynthesis process it performs, is part of the base of the food chain, and being able to successfully accumulate heavy metals (Rehman & Shakoori, 2001) it bioaccumulates in the food chain, which which could cause serious damage to biological diversity. Thus, when studying the effect of heavy metals on the development of Chlorella microalgae from natural freshwater sources, through analysis of their morphological development, pigment production and cell density to assess the consequences of cadmium toxicity, chromium and lead, it will be possible to contribute to the understanding of the functioning of the algae and its possible ecological implications.