Biofilms in Bioremediation

Doug Caldwell caldwell at SASK.USASK.CA
Sat Jan 25 15:39:56 EST 1997

In regard to the possibility that it might be possibile to manipulate cells
and increase bioavailability, it would seem to me that bacterial-self
organization can be enhanced.  There are many combinations of genetic code
which are useful but that could not arise spontaneously through
self-organization due to the lack of adequate pathways in nature.
Similarly there should be many combinations of organisms in biofilm
communities which would not arise spontaneously but which would be
extremely effective if suitable spatial and temporal pathways of
self-organization were provided or if these new combinations were created
by human invention, thus skipping the need for spontaneous

>In article <5c8bru$nck at mserv1.dl.ac.uk>, Jan Kreft
><Jan.Ulrich.Kreft at uni-konstanz.de> wrote:
>> >Question is: what opportunities are out there to *manipulate the cells*
>> >in such a way that biotransformation rates can be enhanced by increasing
>> >bioavailability?xpensive 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 does pay, it is very
>> likely that natural selection does all the work.
>here's a non-ecologist's two cents worth:  I appreciate Jan's attempt at an
>evolutionary perspective, but I would suggest that few ideas in current
>evolutionary theory are carved in stone.  If biosurfactant production pays
>in some ecological context "similar to" that of an existing community, it is
>not logically necessary that there would be a selective path to that paying
>context that could occur within the time constraints of human economic
>requirements.  Evolutionary local stability minima could impede the facile
>selection of paying conditions.  One crude way to assist natural selection in
>finding paying conditions would be to throw a dose of some (short-lived!!!)
>mutagen into the biofilm community to blast away at local stabilities.
>A very crude analogy from conventional microbiology is the use of mutagens
>to assist nature in arriving at relatively rare mutant forms within the
>economic constraints of one or two petri-dishfuls of cells instead of a few
>thousand dishfuls.  This might or might not work with biofilm communities
>but the point is that it seems unnecessarily limiting to assume that natural
>selection could or would arrive at paying conditions on a human economic
>time scale (bioremediation efforts necessarily involve human time scales,
>both in the generation and cleanup of the mess).
>Robert A. Preston, Ph.D.
>Center for Genomic Sciences
>Dept. of Pathology
>University of Pittsburgh
>Pittsburgh PA
>rapr at med.pitt.edu
>rapr at med.pitt.edu

Doug Caldwell
Microbial Colonization Laboratory
Department of Applied Microbiology and Food Science
51 Campus Drive, University of Saskatchewan
Saskatoon, Saskatchewan, S7N 5A8, Canada
Voice: (306) 966-5026 (office), -5042 (colonization lab), -7704 (laser
imaging facility), 934-0711 (home)
Fax:  966-8898
Email:  caldwell at sask.usask.ca
WebSite:  http://zebra.usask.ca

Life is the process by which wisdom arises spontaneously, transcends any
specific individual or group of individuals, and resides within and among
all living things. - Doug Caldwell - Email signature - Nov. 6, 1996 - for
further information see:

Caldwell, D. E. and J. W. Costerton, 1996. Are bacterial biofilms
constrained to Darwin's concept of evolution through natural selection?
Microbiologia SEM 12:347-358.

Caldwell, D. E. R. M. Wolfaardt, D. R. Korber, and J. R. Lawrence. 1996.
Do bacterial communities transcend Darwinism?  In Advances in Microbial
Ecology.  Edited by: J. Gwynfryn Jones.  Published by Plenum Press. New
York.   In Press.

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