For a start, it's highly unlikely that you'll have a pure culture, so
there's no point in staining until you have some isolates. Streak the gunk
you get off the pipes on several different agars - think about the types
of bugs likely to be present. Nutrient agar is fine if you're epecting
bugs that like to grow on rich media full of goodies - the bugs that adapt
to nutrient-poor situations will often not come up unless you use a
mineral medium with low concentrations of a suitable simple substrate.
Some won't grow on solid media. You have to think about the types of bugs
likely to have turned up in the system - and what is favouring their
presence (as a simple example, if you're dealing with a pipe coming from a
vinegar factory, you'd probably be looking for a bug that likes to grow on
acetate at acid pH values); from a paper mill, you might be looking for
soemthing the enjoys organic sulphides).
What sort of water pipes are they? If drinking water, you have a good
chance that you need the nutrient-poor media (although it never hurts to
run nutrient agar as well). If sewage or similar, you'll need richer
media, and maybe also sulphur/nitrogen cycle media. What is the pH of the
water? What might the bugs be eating in situ? If it's corroded metal
pipes, you have to consider that you have local pH variations and a
mini-sulphur cycle....
To be quite honest, I think that the best advice to give you is to look up
your nearest environmental microbiology lab (nearby college, Uni?) and
discuss the problem with them.
JennyG wrote:
> I need to identify what organisms are in the biofilm of our municipal
> water lines. Is there any particular sampling techniques I should
> use? I was planning on just scraping the pipes' walls with a sterile
> spatula and dropping a chunk of the ooze into a sterile container.
> Will this be enough to make sure I can identify it, or should I place
> it onto a nutrient agar on site, without waiting to get back to the
> lab?
>> What do I do once I get to the lab? I don't know where to start. All
> I can think of, off the top of my head, is to gram stain the stuff and
> examine morphology. And maintain a culture of it on nutrient agar.
>> I would greatly appreciate any comments or suggestions.
>> Thanks,
> Jen
>doublehelix at poboxes.com
