Biofilms in Bioremediation

Jan Kreft Jan.Ulrich.Kreft at uni-konstanz.de
Thu Jan 23 13:49:34 EST 1997

At 07:20 21.01.1997 -0800, Ryan N. Jordan wrote:

>I'd like to open discussion about [...] soil bioremediation. [...]
>Technologies to speed up the process have focused on increasing
>contaminant solubilities/desorption rates, including surfactant addition
>and other "soil washing" methods.
>Question is: what opportunities are out there to *manipulate the cells*
>in such a way that biotransformation rates can be enhanced by increasing
>bioavailability? One obvious manipulation is the stimulation of
>biosurfactant production.
>Will the successful application of remediation technologies in the
>future  depend on the ability to *manipulate the organism* in-situ in a
>manner that will minimize cleanup costs (i.e., by eliminating the
>addition of expensive chemicals) and be less-intrusive? [...]

We should take an evolutionary perspective and ask ourselves: As
biosurfactant production is possible, why don't bacteria do it under
particular bioremediation conditions? It seems not to pay. Biosurfactant
production is an investment that must pay. If it doesn't, bacteria that are
manipulated to produce biosurfactants will not survive and all effort was in
vain. If it does pay, it is very likely that natural selection does all the

If manipulating the organism is useless, manipulating the environment is the
other option. One could "increase contaminant solubility" or make
biosurfactant production more profitable for the producers that are already
out there thus stimulating their growth. Maybe adding non-toxic but still
hydrophobic substrates? In many cases, it may still be the best option to do
nothing since this doesn't waste energy.


Dr. Jan-Ulrich Kreft
Microbial Ecology, University of Konstanz
E-mail: Jan.Ulrich.Kreft at uni-konstanz.de

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