Martin Weiss wrote:
> > Has anyone experience setting up Winogradsky colums using only
> > water? [snip]
> > I am hoping the colonies would be more visible and perhaps we could
> > sample more easily, using a thin plastic tube, used to cover fluorescent
> > light bulbs.
> > Any ideas or suggestions?
> > Cheers,
> > Martin Weiss, Ph.D.
Supposedly there's no problem with setting up a water-column Winogradsky
system - there are some nice pictures of such in Brock's Microbiology
But if the reason you want to use water is to avoid the difficulties of spotting
colonies amongst the mud, and getting the things out once you've spotted them,
then you might consider something like the apparatus that I and my colleagues
have used in our lab. It's basically a mud sandwich between plastic
sheets, sealed off and supported by the glass plates and clamp system you
standard vertical gel electrophoresis equipment.
If you're interested in enriching for phototrophs, then it has the advantage
that much more of the mud is exposed to light than in a conventional column.
Plus, when you want to remove colonies, you just undo the clamps, lift off
the glass plates and then the entire mud surface is exposed for sampling.
Either stick a needle through the plastic sheet, or peel the sheet off the
mud. If you do that, you often find that colonies stick to the plastic
rather than the mud.
It's a pretty simple idea, but it was published as a short paper in the
Journal of Microbiological Methods (30(2):161-3). Email me if you want a
Department of Biological Sciences,
University of Waikato,
Hamilton, New Zealand.