OUR PROJECT

The modern lifestyle of a growing population increasingly relies on electronic equipment. As a result, the amount of discarded electronics (e-waste) is rising worldwide. The costs of proper collection and recycling of e-waste may exceed the revenues generated from the recovered materials, due to the complexity of separating them. We propose a synthetic biology approach in Acidithiobacillus thiooxidans and Chromobacterium violaceum to enhance metal recovery from e-waste in a three-step bioleaching process. First, the enzyme TetH will be overexpressed in A. thiooxidans in order to enhance leaching of copper, iron, and tin. Then, C. violaceum will leach gold and silver. Cyanide is responsible for this leaching activity, and the enzymes that produce it will be expressed under the control of a gold sensitive promoter. Overexpression of a cyanide-degrading enzyme will reduce toxicity. Implementing a voltaic cell in the final stage will allow the precipitation of the previously recovered metals.