Two bacterial enzymes efficiently transform the most toxic forms of mercury to less toxic states. These enzymes work even more efficiently in plants than in bacteria, because plants have their own energy source (sunlight) to drive these reactions.
Methylmercury lyase (MerB) acts on (protonolyzes) methylmercury (CH3Hg+) to release less toxic ionic mercury Hg(II). Methyl mercury is the most dangerous form of mercury because it is efficiently biomangified in food webs. Mercury reductase (MerA) acts on (electrochemically reduces) Hg(II) to less toxic volatile metallic Hg(0). Neither Hg(II) or Hg(0) are biomagnified to any significant extent.
	These two enzymes are critical to various strategies of engineered mercury phytoremediaiton (see our publications).

Meagher 2002; Bizily et al., 2000; 2003.

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