Mobilization of selenite by Ralstonia metallidurans CH34.
Ralstonia metallidurans CH34 (formerly Alcaligenes eutrophus CH34) is a soil bacterium characteristic of metal-contaminated biotopes, as it is able to grow in the presence of a variety of heavy metals. R. metallidurans CH34 is reported now to resist up to 6 mM selenite and to reduce selenite to elemental red selenium as shown by extended X-ray absorption fine-structure analysis. Growth kinetics analysis suggests an adaptation of the cells to the selenite stress during the lag-phase period. Depending on the culture conditions, the medium can be completely depleted of selenite. Selenium accumulates essentially in the cytoplasm as judged from electron microscopy and energy-dispersive X-ray analysis. Elemental selenium, highly insoluble, represents a nontoxic storage form for the bacterium. The ability of R. metallidurans CH34 to reduce large amounts of selenite may be of interest for bioremediation processes targeting selenite-polluted sites.
Roux
M
M
Laboratoire de Chimie et Biochimie des Centres Redox Biologiques, CEA-Grenoble, DBMS/CB-CNRS-Université Joseph Fourier, France.
Sarret
G
G
Pignot-Paintrand
I
I
Fontecave
M
M
Coves
J
J
D015502:Absorptiometry, Photon / Q000379:methods; D001673:Biodegradation, Environmental; D003470:Culture Media; D020118:Cupriavidus necator / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D008854:Microscopy, Electron; D018038:Sodium Selenite / Q000378:metabolism* / Q000494:pharmacology
D003470:Culture Media; D018038:Sodium Selenite