title: Biotransformation of mercury by bacteria isolated from a river collecting cinnabar mine waters.
abstract: One hundred six strains of aerobic bacteria were isolated from the Fiora River which drains an area of cinnabar deposits in southern Tuscany, Italy. Thirty-seven of the strains grew on an agar medium containing 10μg/ml Hg (as HgCl2) with all of these strains producing elemental mercury. Seven of the 37 strains also degraded methylmercury. None of 106 sensitive and resistant strains produced detectable monomethylmercury although 15 strains produced a benzene-soluble mercury species. Two strains of alkylmercury (methyl-, ethyl- and phenylmercury) degrading bacteria were tested for the ability to degrade several other analogous organometals and organic compounds, but no activity was detected toward these compounds. Mercury methylation is not a mechanism of Hg resistance in aerobic bacteria from this environment. Growth of bacteria on the agar medium containing 10μg/ml HgCl2 was diagnostic for Hg detoxification based on reduction.
authors.affiliation: Dipartimento di Biologia Ambientale, Universita di Siena, Siena, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Baldi
authors.forename: M
authors.initials: M
authors.lastname: Filippelli
authors.forename: G J
authors.initials: GJ
authors.lastname: Olson