PLoS Genetics (Apr 2007)

A tale of two oxidation states: bacterial colonization of arsenic-rich environments.

  • Daniel Muller,
  • Claudine Médigue,
  • Sandrine Koechler,
  • Valérie Barbe,
  • Mohamed Barakat,
  • Emmanuel Talla,
  • Violaine Bonnefoy,
  • Evelyne Krin,
  • Florence Arsène-Ploetze,
  • Christine Carapito,
  • Michael Chandler,
  • Benoît Cournoyer,
  • Stéphane Cruveiller,
  • Caroline Dossat,
  • Simon Duval,
  • Michael Heymann,
  • Emmanuelle Leize,
  • Aurélie Lieutaud,
  • Didier Lièvremont,
  • Yuko Makita,
  • Sophie Mangenot,
  • Wolfgang Nitschke,
  • Philippe Ortet,
  • Nicolas Perdrial,
  • Barbara Schoepp,
  • Patricia Siguier,
  • Diliana D Simeonova,
  • Zoé Rouy,
  • Béatrice Segurens,
  • Evelyne Turlin,
  • David Vallenet,
  • Alain Van Dorsselaer,
  • Stéphanie Weiss,
  • Jean Weissenbach,
  • Marie-Claire Lett,
  • Antoine Danchin,
  • Philippe N Bertin

DOI
https://doi.org/10.1371/journal.pgen.0030053
Journal volume & issue
Vol. 3, no. 4
p. e53

Abstract

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Microbial biotransformations have a major impact on contamination by toxic elements, which threatens public health in developing and industrial countries. Finding a means of preserving natural environments-including ground and surface waters-from arsenic constitutes a major challenge facing modern society. Although this metalloid is ubiquitous on Earth, thus far no bacterium thriving in arsenic-contaminated environments has been fully characterized. In-depth exploration of the genome of the beta-proteobacterium Herminiimonas arsenicoxydans with regard to physiology, genetics, and proteomics, revealed that it possesses heretofore unsuspected mechanisms for coping with arsenic. Aside from multiple biochemical processes such as arsenic oxidation, reduction, and efflux, H. arsenicoxydans also exhibits positive chemotaxis and motility towards arsenic and metalloid scavenging by exopolysaccharides. These observations demonstrate the existence of a novel strategy to efficiently colonize arsenic-rich environments, which extends beyond oxidoreduction reactions. Such a microbial mechanism of detoxification, which is possibly exploitable for bioremediation applications of contaminated sites, may have played a crucial role in the occupation of ancient ecological niches on earth.