TABLE 1.

Electron donors and acceptors used in Hg methylation tests

Culture	Electron donor	Electron acceptor(s)
D. palmitatis	20 mM acetate	55 mM Fe(III)
G. hydrogenophilus	20 mM acetate	55 mM Fe(III)
G. sulfurreducens	20 mM acetate	55 mM Fe(III), 40 mM fumarate
G. metallireducens	20 mM acetate	55 mM Fe(III), 30 mM nitrate
S. alga	30 mM lactate	55 mM Fe(III), 30 mM nitrate
S. oneidensis	30 mM lactate	55 mM Fe(III), 30 mM nitrate
S. putrefaciens	30 mM lactate	55 mM Fe(III), 30 mM nitrate