Bioleaching, genome biology of
acidophilic bioleaching microorganisms,
comparative genomics and metagenomics.
As defined in a nice, simple overview by William H. Desher, bioleaching
is the extraction of a metal from sulfide ores or concentrates using
materials found native to the environment; namely, water, air and microorganisms.
In other words, bioleaching is the commercialization of the ability
of certain bacteria and archaea, found in nature, to catalyze the oxidation
of sulfide minerals. It is the leaching of sulfide minerals that distinguishes
bioleaching from conventional acid leaching wherein only oxidized minerals
are leached.
An associated process is biooxidation. This is the oxidation
of sulfide minerals associated with, but not necessarily part of, the
mineral of interest. Bioleaching is used today in commercial operations
to process ores of copper, nickel, cobalt, zinc and uranium, whereas,
biooxidation is used in gold processing and coal desulfurization.
Some pictures of bioleaching processes and associated background can
be found here and more information about
the biology of bioleaching can be found here.
