Dear Dr. Brelles-Mariño,
Welcome to the biofilm field. With respect to your question about whether
biofilms of denitrifying bacteria are present on clay-like materials
(ceramics?), I would recommend some form of microscopy. Scanning electron
microscopy, epifluorescent or confocal microscopy should be able to give
you an idea of the distribution and community structure of adherent
organisms. This will necessarily involve some perturbation of your
fermentor during specimen removal, but would be the most direct approach to
identifying whether adherent organisms were present.
We had a debate in this discussion group about 6 months ago as to how many
organisms constitute a biofilm. I think it safe to say that everyone
agreed that one single attached microorganism was not a biofilm, and that
an adherent community of microorganisms such as dental plaque was a
biofilm. Between those extremes, there were some differences of opinion.
Rob Palmer, currently of NIDCR, will be chairing a session at Biofilms 2000
(Big Sky Montana, USA July 16 - 20, 2000) to discuss this point. You can
get some information about this meeting (which will feature most of the
international biofilm researchers) on the web site for the Center for
Biofilm Engineering at Montana State University http://www.erc.montana.edu
or the conference web site http://www.asm.org/mtgsrc/B2Kg.htm
I would really encourage you to consider attending as this will be a superb
At 03:31 PM 2/8/00 +0000, you wrote:
>We are new to Biofilms. Our group is interested in using single-species
>biofilms to decontaminate waters from nitrate. Although we have been
>reading lots of papers, most of them deal with different analytical
>methods to evaluate already established biofilms. But before choosing an
>analytical method, we would like to know if we REALLY have a biofilm. We
>are growing our bacteria in glass columns using a porous clay-like
>material (quite similar to broken bricks) which is obviously not
>transparent. Which is the best approach to determine the presence of a
>biofilm without disturbing it too much?
>Thank you for your suggestions!
>Dr. Graciela Brelles-Mariño
>Dept. of Soil Microbiology and Symbiotic Systems
>Estacion Experimental del Zaidin,
R.J.C. (Bob) McLean, Ph.D.
Southwest Texas State University
601 University Drive
San Marcos, Tx 78666
Email: RM12 at swt.eduhttp://www.bio.swt.edu/micro/mclean/mclean.html
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