contaminant

suter at VAX.MPIZ-KOELN.MPG.dbp.de suter at VAX.MPIZ-KOELN.MPG.dbp.de
Wed Sep 9 08:42:18 EST 1992


dear netters,
i have a completely rediculous observation, which could be meaningful in some 
way.
the problem is the following: i prepare a stock solution of 1 M MgSO4,
autoclave, poor out (under sterile conditions) half of the contents, and
store the remainder on my bench. 
guess what happens: after half a year at RT, a fungus (diameter 2 cm, biomass
unknown) is floating around.
this happens only with this chemical. i accept that the initial infection is due
to my sloppy handling (i am not that bad tho...).

my question however is: where does the biomass come from ? from:
1. CO2 in the air above the solution (this would mean c-fixation!)
2. a contaminant in the MgSO4 (this would be bad news, since the experiment
is reproducible with several different MgSO4 lots from diff. companies) could
a contaminant explain the apperant high biomass?
3. somehow a carbon source is introduced into the bottle during autoclaving
or extremely sloppy handling (i only notice this with this solution !)

you are probably all grinning at this stage....any microbiologists out there
with an explanation ?

cheers, clemens
----------------------------------> cut here <----------------------------------
Clemens Suter-Crazzolara, PhD
Max-Planck-Institut fuer Zuechtungsforschung
Abteilung Genetische Grundlagen der Zuechtungsforschung
Carl-von-Linne Weg 10
5000 Koeln 30
Tel. xx49-221-5062.221           fax. xx49-221-5062.21
suter at vax.mpiz-koeln.mpg.dbp.de
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