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.

The present invention generally relates to methods of biological reduction of metal-cyanide complexes after metal-cyanidation and methods of biologically hydrolysing cyanide. More particularly, the present invention allows the engineering of an integrated synthetic lixiviant biological system to be housed within a synthetic host (such as the cyanogenic Chromobacterium violaceum) for efficient precious metal recovery and toxic metal remediation of electronic waste; with up to four main components/modules in the design and engineering of the synthetic host: 1) synthetic cyanogenesis; 2) synthetic metal recovery; 3) synthetic cyanolysis; and 4) synthetic circuits for lixiviant biology. Bacteria capable of reducing ionic metal to ionic metal (such as gold or silver) as nanoparticles, comprising mercury(ll) reductase (MerA) comprising a substitution mutation at position V317, Y441, C464, A323D, A414E, G415I, E416C, L417I, I418D, or A422N, are also disclosed. Processes of synthetic cyanide lixiviant production using genetically engineered bacterium transformed with a heterologous hydrogen cyanide synthase gene and a heterologous 3-phosphoglycerate dehydrogenase mutant gene are also disclosed. Processes of synthetic cyanolysis using a genetically engineered bacterium transformed with a heterologous nitrilase gene are also disclosed.

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.

The present invention generally relates to methods of biological reduction of metal-cyanide complexes after metal-cyanidation and methods of biologically hydrolysing cyanide. More particularly, the present invention allows the engineering of an integrated synthetic lixiviant biological system to be housed within a synthetic host (such as the cyanogenic Chromobacterium violaceum) for efficient precious metal recovery and toxic metal remediation of electronic waste; with up to four main components/modules in the design and engineering of the synthetic host: 1) synthetic cyanogenesis; 2) synthetic metal recovery; 3) synthetic cyanolysis; and 4) synthetic circuits for lixiviant biology. Bacteria capable of reducing ionic metal to ionic metal (such as gold or silver) as nanoparticles, comprising mercury(11) reductase (MerA) comprising a substitution mutation at position V317, Y441, C464, A323D, A414E, G415I, E416C, L417I, I418D, or A422N, are also disclosed. Processes of synthetic cyanide lixiviant production using genetically engineered bacterium transformed with a heterologous hydrogen cyanide synthase gene and a heterologous 3-phosphoglycerate dehydrogenase mutant gene are also disclosed. Processes of synthetic cyanolysis using a genetically engineered bacterium transformed with a heterologous nitrilase gene are also disclosed.