Transformation and Precipitation of Toxic Metals by Pseudomonas Maltophilia.

摘要

The aims of this research were to study each of the various molecular mechanisms whereby toxic metal cations and oxyanions were chemically transformed by Pseudomonas maltophilia strain OR02. The research effort focused on the microbial-dependent transformations of mercury, selenium, tellurium, chromium, lead, cadmium, silver, and gold. The NADPH-dependent reduction of Hg(II) was catalyzed by an inducible mercuric reductase. The reduction of selenite and tellurite to their insoluble elemental forms was mediated by an intracellular glutathione reductase that utilized the spontaneously-formed bis(glutathio)Se or bis(glutathio)Te, respectively, as pseudosubstrates. The 3-electron reduction of hexavalent chromium was catalyzed by a membrane-bound chromate reductase. The enzymatic basis for the transformation and immobilization of soluble lead(II), cadmium(II), silver(I), and gold(III) was not immediately apparent. This project could provide useful information toward the eventual exploitation of P. maltophilia and related organisms for the removal of toxic metal wastes from selected, heavily polluted sites. Bioremediation, Mercury, Selenium, Chromate Lead.