> ==========
> bionet/microbiology #5966, from dmr at nhm.ac.uk, 1700 chars, 20 May 1997
09:21:43 +0
> ----------
> Article: 7011 of bionet.microbiology
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> From: dmr at nhm.ac.uk (Dave Roberts)
> Newsgroups: bionet.microbiology
> Subject: Enrichment media with sulphide
> Date: 20 May 1997 09:21:43 +0100
> Sender: lpddist at mserv1.dl.ac.uk> Distribution: bionet
> Message-ID: <5lrmun$d3p at mserv1.dl.ac.uk>
> X-Sender: dmr at mailserver.nhm.ac.uk> Original-To: microbio at dl.ac.uk, protista at dl.ac.uk> Lines: 32
>> Hi everyone,
>> Does anyone have any advice to offer about the composition of an
> enrichment medium for organisms from an acidic, high sulphide
environment
> (volcanic discharge environment). Chemical analysis indicates that
there
> is 1 - 2 mM H2S which I assume to be the primary electron acceptor but
> does not reveal a source of nitrogen or phosphorous in the system.
>> I want to maintain and gently enrich samples in the search for
> phagotrophic eukaryotes.
>> Any ideas would be gratefully received.
>> Thanks, Dave
>> --
> Dr D.McL. Roberts, Tel: +44 171 938 8790
> Dept. Zoology, Fax: +44 171 938 9158
> The Natural History Museum,
> Cromwell Road,
> London SW7 5BD
> Great Britain Email: dmr at nhm.ac.uk>> --
> Dr D.McL. Roberts, Tel: +44 171 938 8790
> Dept. Zoology, Fax: +44 171 938 9158
> The Natural History Museum,
> Cromwell Road,
> London SW7 5BD
> Great Britain Email: dmr at nhm.ac.uk>Hello Dave,
Trying to incorporate sulphide into a medium is not easy and will make
you unpopular (unless you like having your lab to yourself). Colloidal
sulphur is a possibility. You can disolve a little sulphur in acetone
and when added to a medium the sulphur comes out as a fine suspension
(the acetone is driven off in sterilisation).
Alternatively the easiest substrate is probably thiosulphate. It's
stable, cheap, easily incorporated without tangling up other
constituents, and is usually accepted by sulphur oxidisers. I have been
using it to demonstrate sulphur oxidation for years. Barium sulphate
precipitates, barium thiosulphate does not.(Although there is usually
enough sulphate in most thiosulphate salts to give a faint ppt.).
Peter Harris,
Dept of Soil Science,
University of Reading.
AKA P.J.Harris at reading.ac.uk
