Ask A Scientist© Molecular Biology Archive

name       Rockne
status     educator
age        30s

Question - What are some examples of which man
made materials bacteria does or does not break down? Where could I find
more information on this topic?

Bacteria can degrade so many compounds that your
question is nearly impossible to answer. I'll give
some interesting web sites on the application of
bacterial degradation. Take a look at the Virtual
Museum of Bacteria for general properties and
diversities of bacteria (www.bacteriamuseum.org). In
this museum a display is planned on applied
microbiology which will treat some of the topics you
may be interested in. Check in a month or so. Follow
just some examples that I hope are useful. Note that
there is no omnipotent bacterium that can do all this.
They are all different species, in part not even well
characterized or combinations of species working in
concert.
Bacteria can degrade oil
(http://www.uscar.org/techno/bacteria.htm) and here's
how they do it
(http://www.mother.com/~wege/biodeg.htm). They can
also degrade other toxic organic compounds, including
polyaromatic hydrocarbons
(http://www.icp.ucl.ac.be/annrep97/degr/degr97.html).
They can degrade (that is, corrode) metals which is
mostly not wanted
(http://www.icp.ucl.ac.be/annrep97/degr/degr97.html).
They can degrade biological material in, and thus
clean, waste water, check here what research is going
on in this field
(http://info.tuwien.ac.at/ficu/projects/prj18.htm).
Bacteria can detoxify chemicals in which heavy metals
are present, though they cannot get rid of the heavy
metals themselves. Similarly, Deinococcus radians is
used to detoxify radio active waste which is often
mixed with highly toxic chemicals, not because D.
radians can 'destroy' radioactivity but because it is
highly resistant to it. See the museum display
(http://www.bacteriamuseum.org/species/Dradiodurans.shtml).
So in conclusion, probably every organic compound can
be degraded by bacteria. Maybe we haven't identified
the proper bacteria for some compounds (some PCBs and
DDT are very stable in the environment) but that is
not to say that there are no microbes around who can
do it. Maybe we haven't looked properly.
What bacteria can't do is change the atoms:
radioactive isotopes and toxic elements cannot be
eliminated. At the best the latter can be incorporated
in metallo-organic compounds that are less toxic.

Dr. Trudy Wassenaar
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