Tiny cleaners

WATER with arsenic in it may be the most
poisonous drink for us, but for two
strains of bacteria, discovered by
French researchers, it is the daily means
of sustenance. A stream flowing
through the abandoned Carnoules
lead and zinc mine in the Cevennes
mountains in southern France was
found to be the home of these
bacteria.

Researchers led by Michel Leblanc
from the French national research
agency, CNRs, at the University of
Montpellier, believe that the bacteria
could belong to the Thiobaciiius and
Leptothrix strains. These convert the
soluble form of arsenic into a less toxic
precipitate. Said John Fawell, chief toxicologist at the Water Research Centre
in Medmenham, Buckinghamshire, "it
would be extremely exciting if these
bacteria could be used for treatment of
drinking water".