COLEADER.ZIP

Sustainable treatment of copper, lead and zinc based on E. coli.

Heavy Metal Pollution

Heavy metal pollution has become a worldwide environmental problem in both developed and developing countries. It poses a wide-range and long-lasting risk on human society and the eco-system, as it’s extremely hard to detect non-biodegradable, and continues to accumulate biologically through the food chain.

Existing Methods

Non-biological approaches have been employed to remove heavy metal pollutants. However, these methods have serious drawbacks such as high cost, high energy-demanding, complicated process and high risk of secondary pollution.

Our Solution

In an attempt to address the aforementioned problems, we have developed a sustainable strategy that can detect and remove Zn²⁺, Cu²⁺and Pb²⁺, using E. coli as our engineered bacteria. Our design can be divided into the following parts.

Ion Sensor System

In order to sense Zn²⁺, Cu²⁺and Pb²⁺ in the environment, we designed an induction system to sense Zn²⁺, Cu²⁺and Pb²⁺ and activate the downstream genes.

Surface display system

In order to reduce the concentration of Zn²⁺, Cu²⁺and Pb²⁺, surface display system is employed, featuring fusion expression of membrane proteins OmpC, lpp-OmpA and metal binding parts ZBP, CBP, PbrR that combine Zn²⁺, Cu²⁺and Pb²⁺ respectively.

Molecular Magnet

As concentration of heavy metal ions is detrimental to the survival of our engineered bacteria, metallothioneins(MTs) are continuously expressed in our engineered bacteria to increase their tolerance to heavy metals, with SUMO fusion expression system adopted to optimize the function of MTs.

Kill switch

We introduced the kill switch based on the arabinose operon and the endotoxin RelE. When the concentration of heavy metal ions in the environment is reduced, we can inhibit the growth of bacteria by adding arabinose.

Education & Communication

From primary students to physically challenged people, we reached out to a wider audience through various modes of communication including series of lectures, reading materials, videos, etc. These are tailored to each group of audience while gathering constructive feedbacks.