A method for reducing toxic mercury in wastewater effluent comprises the steps of: identifying a system into which wastewater effluent is introduced, the wastewater effluent including organic compounds and organomercurial compounds; producing a treatment composition comprising a solution including a surfactant, digestive microbes suspended in the solution, and mercury-transformative microbes suspended in the solution; and providing the treatment composition into the system containing the wastewater effluent, such that the digestive microbes degrade the organic compounds in the wastewater effluent, and the mercury-transformative microbes reduce the organomercurial compounds in the wastewater effluent into nontoxic volatile elemental mercury. In certain systems for reducing toxic mercury in wastewater effluent, a biological capture medium is positioned within a vessel and configured to provide a capture point for microbes to adhere to and create biofilms. One such system is a dental evacuation system in which wastewater effluent is introduced into the system via an aspirator.

A method for reducing toxic mercury in wastewater effluent comprises the steps of: identifying a system into which wastewater effluent is introduced, the wastewater effluent including organic compounds and organomercurial compounds; producing a treatment composition comprising a solution including a surfactant, digestive microbes suspended in the solution, and mercury-transformative microbes suspended in the solution; and providing the treatment composition into the system containing the wastewater effluent, such that the digestive microbes degrade the organic compounds in the wastewater effluent, and the mercury-transformative microbes reduce the organomercurial compounds in the wastewater effluent into nontoxic volatile elemental mercury. In certain systems for reducing toxic mercury in wastewater effluent, a biological capture medium is positioned within a vessel and configured to provide a capture point for microbes to adhere to and create biofilms. One such system is a dental evacuation system in which wastewater effluent is introduced into the system via an aspirator.

There is provided a transgenic animal comprising heterologous nucleic acid encoding a bacterial organomercurial lyase and/or a bacterial mercuric reductase, wherein the transgenic animal expresses the bacterial organomercurial lyase and/or a bacterial mercuric reductase to reduce the toxicity of a mercury compound.

The present disclosure provides a fungus and a microbial agent for treating mercury contamination, use thereof, a mercury removal method, and a method for identifying a fungus capable of treating mercury contamination, and relates to the technical field of biological mercury removal. The present disclosure provides a Metarhizium fungus and 8 species of non-Metarhizium fungi for treating mercury contamination, a method for identifying a fungus capable of treating mercury contamination, and enzymes for removing methylmercury and divalent mercury, which provides a genetic basis for treating mercury contamination with recombinant fungi or bacteria.