Team:UFAM Brazil/Overview

Overview

 In Amazon, mercury (Hg) is broadly used in mines during gold amalgamation, and it’s considered one of the major pollutants on this region. On amazon rives, there is about 3.000 tons of mercury and can be found in it different forms. This metal has as main toxic characteristic bioaccumulation. This can be explained by metal attraction to organic groups which cause the element conversion to its most toxic form: methylmercury. Considering that riverine population has as main protein source, fish consumption, they are exposed to high Hg concentration, having several effects on health as: abdominal pain, diarrhea, osteoporosis, neurodegenerative and kidney diseases, as well as psychological and psychomotor impairments. (Biondo, 2008)

 On environment, the successive transformations on Hg forms, represent risks not just to “superior” but also to microorganisms (Neves Pinto, 2004). However, it is known that some bacteria have resistance to mercury, including Serratia marcescens, Pseudomonas putida, Cupriavidus metallidurans and Entereobacter (Giovanella et al., 2010). Those bacteria present bioremediation characteristics, by convertion of Hg²⁺ and CH3Hg available on aquatic environments, into Hg⁰, less toxic form of this metal (volatile at room temperature). (Biondo, 2008).

 To reduce environmental problems caused by mercury, this project aims to use those bacteria skills, to construct a treatment station for effluents contaminated with Hg, through synthetic biology. The system will be composed by four tanks, with bacteria capable of: on tank 1, to detect Hg; on tank 2, for Hg bioaccumulation; on tank 3, to volatilize Hg (that will be captured and precipitated after); and finally on tank 4, will again detect Hg to analyze the system yield. In case that the effluent still contaminated, it will return to tank 2 until mercury concentrations are irrelevant.

In this project, we were able to characterize the designed promoter induced by mercury, through expression of the reporter protein, GFP. Even in low Hg concentrations (under 0.02µg/ml). And our bioaccumulation and bioremediation devices showed to be efficient. Both were capable of removing around 60% of Hg from medium.

 With it, it is expected to produce a system capable of reduction and/or to avoid harms caused by mercury on ecosystem. Since soil until human beings. By making a system that is easy to manipulate and analyze. Besides being a low cost alternative for market.