Patrick Diep, a PhD Candidate supervised by Profs. Alexander Yakunin and Krishna Mahadevan, placed 3rd at the 60th Conference of Metallurgists which was virtually hosted by MetSoc from August 17-19.
Currently, liquid mine effluents may contain dissolved metals at concentrations too low to be economically extracted by existing technologies, yet too high for environmental discharge. Treating this wastewater often requires chemical precipitation of the dissolved metals using limestone and subsequent disposal of the sludge in tailing impoundments. While this is a cost-effective solution to meet regulatory standards, it represents a lost opportunity. Diep’s paper titled, Bioengineered microorganisms for nickel removal, demonstrates the use of synthetic biology to engineer microorganisms to remove dissolved nickel from simulated liquid mine effluents at ppb-ppm concentrations. Specifically, Escherichia coli is artificially equipped with a class of highly-specific transporter protein systems evolved over millions of years to capture nickel from metal-scarce environments. Preliminary results at bench scale reveal the engineered strain removes 97% of dissolved nickel from a 10 mg/L (ppm) solution in 3 hrs, which is faster than the literature’s best reported strain by two-fold. The engineered strain also performs at least seven-fold better than the non-engineered strain. Immobilization of the engineered strain to enable easier aqueous separation and synthetic biology design strategies to enable lysis-free metal recovery are the immediate next steps.