Diseño de un biosensor bacteriano para la identificación cualitativa de mercurio (Hg)

Abstract

Heavy metals are toxic compounds for living beings due to their ability to bioaccumulate, which causes serious problems in ecosystems. Among them, mercury stands out as one of the most toxic pollutants due to its high capacity to cause health problems in exposed species. The most widely used reference technique for the detection of heavy metals is atomic absorption spectrophotometry, which is based on the absorption of radiant energy by atoms in their ground state. However, this technique is characterized by long waiting times for results and by the high costs associated with the acquisition and maintenance of equipment, as well as the necessary reagents. The objective of this research is to use biotechnological tools to optimize processes and improve the detection of heavy metals, such as mercury. To do this, a biological device was developed capable of identifying this compound by engineering a genetic sequence aimed at the production of a marker protein. The process was carried out on bacteria isolated from the Gulf of Guayaquil, which were subjected to a chemical transformation to allow their genetic manipulation. After completing the transformation, the selective capacity was evaluated, which showed a tipping point from 0.04 ppm in the concentration of mercury chloride (HgCl₂), however, the production of the GFP protein was not detected in the presence of cadmium (Cd), chromium (Cr), silver (Ag) and lead (Pb).The sensitivity of the bacteria to different concentrations 0.5 to 3.25 ppm of mercury (Hg) was evaluated, which was detected by mercury (Hg) through the production of green fluorescent protein (GFP).