coliform testing

Liz Asple lasple at bio.ie
Thu Nov 15 11:48:33 EST 2001


I'm actually looking for an easy and specific procedure to find out any
coliform contamination in bacterial mixtures containing different kinds of
microorganisms (total concentration 10*8 bacteria/ml) mixed together.

First I thought to realise MacConkey plate counting but since more than 50%
of my bacteria are gram negative, this test doesn't appear as the most
Then as complementary test I thought to use a test kit involving
B-galactosidase reaction (with ONPG)... but some bacteria present a
B-galactosidase activity...
I know those features for some bacteria but for others I don't have a
I asked NCIMB: they didn't know the arthrobacter and polymyxa gram-stain and
had no data concerning the potential B-gal activities... and I couldn't find
the data for the specific strains described below in the "Bergey's"... I'm
maybe blind... please help!!!

In order to choose the most efficient and reliable test procedures I'd need
data about the gram-stain and lactose degrading activity of following

arthrobacter parrafineus (ncimb 10699)

arthrobacter sp(ncimb 10407)

arthrobacter sp(ncimb 12631)

bacillus schlegelii (ncimb 13107)

acinetobacter sp(ncimb 8250)

acinetobacter sp(ncimb 13260)

acinetobacter sp(ncimb 9689)

acinetobacter sp(ncimb 11742)

brevibacillus brevis (ncimb 9372)

paenibacillus polymyxa (ncimb 8094)

paenibacillus polymyxa (ncimb 8228)

paenibacillus polymyxa (ncimb 8527)

cellvibrio mixtus (ncimb 8634)

cytophaga hutchinsonii (ncimb 9469)

cytophaga johnsonae(ncimb 11054)

lysobacter enzymogenes (ncimb 11894)

lysobacter enzymogenes (ncimb 9924)

thiobacillus novellus (ncimb 10456)

thanks in advance...

More information about the Microbio mailing list

Send comments to us at biosci-help [At] net.bio.net