dstemke at umabnet.ab.umd.edu
Thu Jun 27 09:49:56 EST 1996
On Tue, 25 Jun 1996, Doug Stemke wrote:
> On Tue, 25 Jun 1996, Michael Casey wrote:
> > I am studying the rate of growth of Clostridium tyrobutyricum in acid medium
> > and have found them to be very sensitive to the presence of oxygen. I follow
> > the growth rate by measuring the turbidity at 650 nm. I have tried using
> > different techniques to reduce the oxygen content of the medium but with
> > little success.
> > Gassing with CO2 does not reduce the oxygen content sufficiently.
> > The addition of cysteine to the medium is also not sufficient but the
> > presence of sodium thiogllycolate inhibits growth.
> > The addition of Oxyrase, a commercial enzyme preparation which removes
> > oxygen, causes turbidity and prevents accurate measurement of growth.
> > Does anyone have an idea how I could reduce the oxygen content of
> > the medium without causing turbity
> I used to work with an extremely oxygen sensitive organism,
> a Methanosarcina ssp.. What we had in the lab was a manifold attached to
> both a vacuum pump and various gasses (I suppose you could use CO2).
> The organisms were grown in serum vials that were crimped
> shut and contained a rubber stopper. The manifold had several needles
> attached to it that could be opened and closed. You would run each medium
> through several cycles of vacuum and pressurized gassing.
> There are a number of other techniques that are really useful. I highly
> suggest reading 'Archaea, A Laboratory Manual' and specifically the
> section on the methanogens. There is a really excellent chapter in there
> by Sowers and Noll that shows these procedures in detail; both
> visual as well as text explainations.
> Good luck
My appologies to those of you I may have already sent this info to. I've
had several requests for information on the Archaea manual. The full
info is as follows:
Archaea-A Laboratory Manual
eds. F.T. Robb, et al.
Cold Spring Harbor Laboratory Press, 1995
This is now printed as a three volume set (Halophiles, Methanogens and
Thermophiles). Those of you specifically interested in working with
extreme anaeobes would be interested in the methanogen chapters and
especially the chapter by Sowers and Noll, "Techniques for Anaerobic
Growth" which has detailed pictures for engineering an anaerobic lab.
Here's some ordering info:
Cold Spring Harbor Laboratory Press
10 Skyline Drive
Plainview, New York 11803-2500 USA
In US and Canada they have a toll free #
Hope this is of further interest!
Biological Process Technology Institute
University of Minnesota
More information about the Microbio