To develop transgenic algae with enhanced mercury binding capacity expressing a heavy metal fluorescent biosensor to monitor the state of mercury saturation and its kinetics. These algae will be used for remediation of mercury contaminated sediments and effluents.

Mercury bio-accumulation is pervasive in the Great Lakes food chains. Systems are needed for the recovery of mercury from contaminated sediments as well as for the prevention of mercury releases from effluents that are discharged into the Great Lakes.

Transgenic algae will be generated expressing one or more proteins to monitor and enhance mercury binding in vivo. The mercury binding/monitoring protein designated Chameleon-MT includes a metallothionein-II (MT-II) mercury-binding protein fused to cyan (CFP) and yellow fluorescent proteins (YFP). Following mercury binding the MT-II protein undergoes a conformational change that facilitates fluorescence resonance energy transfer (FRET) between the CFP and YFP enhancing the fluorescence emission from YFP. The ratio of YFP/CFP fluorescence can be used to quantify the state of mercury binding to Chameleon-MT. Chameleon-MT will be used to monitor the mercury binding capacity of transgenic microalgae used to recover mercury from contaminated effluents and sites. 2) Chameleon-MT and a plasma-membrane bound alpha-dimer of metallothionein will be co-expressed in transgenic algae to both monitor and enhance mercury binding. 3) A prototype device for mercury recover and quantification will be tested using various mercury and other metals. 4) Biocontainment studies will be carried out to demonstrate whether stacking various gene mutations will preclude growth and gene transfer from transgenic algae in the wild.