In the field of biodetection and bioremediation, despite numerous proofs of principle, most bioreporters and bioactuators have remained confined to the laboratory. Also bacterial reporters and actuators have NOT been rational enough in design and NOT complex enough in function. Additionally, we notice that genetic manipulation in this field needs streamline methods and it's time for a series of issues on the field application to be taken into consideration.

In this summer, we are engineering our bacteria to resolve these hard truths mentioned above. Firstly, we exploit MerR family transcription factors and rational designs such as dose-response alignment to construct a series of biorepoters for heavy metal detection. Rational design for genetic circuits enables cellular sensory and regulatory components to work much more efficiently and robustly. These bioreporters are expected to discriminate concentration ranges of certain heavy metal in water independently of incubation time and bioreporter activity. This means that the field application can be carried out without the need for costly equipment while response quality and sensor sensitivity are still kept. Secondly, we are constructing bioactuator strains that decontaminate heavy metals from polluted water. This will be accomplished by inductively expressing engineered MerR family TFs on surface, periplasm and cytosol of E.coli cells. In our bioactuators, MerR family TFs are engineered into single-chain, antiparallel, coiled coil peptides that mimic the metal binding domains, which will reduce costs of metal binding. As MerR family TFs share high homology and almost each species of heavy metal has a corresponding MerR family TF, we can say we are developing a streamlined method to construct heavy metal decontamination kits which are composed of high-performance bioreporters and bioactuators.