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Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site
Author(s) -
Blake Robert C.,
Choate Donna M.,
Bardhan Smriti,
Revis Nathaniel,
Barton Larry L.,
Zocco Thomas G.
Publication year - 1993
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620120806
Subject(s) - hexavalent chromium , chemistry , chromate conversion coating , pseudomonas , nuclear chemistry , chromium , metal , environmental chemistry , inorganic chemistry , bacteria , organic chemistry , biology , genetics
Pseudomonas maltophilia strain O‐2, isolated from soil at a toxic waste site in Oak Ridge, Tennessee, catalyzed the transformation and precipitation of numerous toxic metal cations and oxyanions. When a viable inoculum (1%) of O‐2 was introduced into nutrient broth containing Hg(II), Cr(VI), Se(IV), Pb(II), Au(III), Cd(II), Te(IV), or Ag(I), effective removal of the toxic metal was complete within 1, 1, 2, 2, 2, 4, 5, and 7 d, respectively. The NADPH‐dependent reduction of Hg(II) to Hg 0 was catalyzed by an inducible mercuric reductase. The reduction of selenite and tellurite to their insoluble elemental forms appeared to be mediated by an intracellular glutathione reductase that utilized the spontaneously formed bis(glutathio)Se(II) or bis(glutathio)Te(II), respectively, as pseudosubstrates. The three‐electron reduction of hexavalent chromium was catalyzed by a membrane‐bound chromate reductase. The enzymatic basis for the remaining metal transformations was not immediately apparent. It is anticipated that Pseudomonas maltophilia and related organisms could eventually be exploited for the removal of toxic metal wastes from selected, heavily polluted sites.