Abstract: The present invention provides for the removal of mercury utilizing Mer proteins. After the Mer proteins have been expressed and isolated, or alternatively using the native Mer protein complex, either can be used as a chelating agent to remove mercury from any aqueous mercury containing environment. The Mer protein may be used in a solution to bind mercury where the solution contains a Mer proteins may be reversibly attached to a removal apparatus as a Mer ligand. The Mer complex may also be used within a bioreactor to bind and reduce Hg(2+). The bioreactor may have any competent bacteria capable of producing a Mer complex attached within the bioreactor also containing an inlet and an outlet.