A way of measuring bacterial activity? Ideas?

[David Slomczynski]

In article <3b761bcb at dnews.tpgi.com.au>, "Halogen" <halo &anti spam& 
gen at tpg.com.au> says...
> Basically I have an undergraduate project to test this new idea for a
> bioreactor.
What about using tetrazolium dyes? They are used commonly to test for 
metabolic activity.

botrytis
> 
> Does anyone know a simple way of quantitatively measuring a product produced
> by bacteria without resorting to using equipment like HPLC?
> 
> I've tried measuring H2S produced by sulphate reducing bacteria, but this is
> difficult to work out since it's only practical to measure it as a gas and a
> lot is staying dissolved in the liquid in the bioreactor.
> I've tried using pigment produced by psuedomonas fluorescens, but this
> didn't work due to this bacteria only producing pigment under certain
> conditions.
> 
> Any other ideas?  I'm really looking for a bacteria I can easy assay a
> metabolic product of using a colour reaction and a spectrophotometer, but I
> can't seem to find a way to do this anywhere.
> 
> Thanks,
> 
> 
> 
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