Date: 04 August 1999
From: Scotian Halibut <scotianhalibut@klis.com>
To: BRINE-L@LISTSERV.UGA.EDU
QUESTION:
I would like to invite discussion on methods used in the disinfection of
Artemia during/after enrichment. What are you using, what bacterial levels do you think are acceptable?
Melissa
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COMMENTS 1:
Using standard enrichment procedures, total bacterial levels in the enrichment medium easily reach numbers of 10 to 100 million of bacteria per ml.
Inve Aquaculture NV however has developed a DC (Disinfecting Continuously) range of enrichment products (DC Selco(R), DC Super Selco(R) and DC DHA Selco(R)) aiming at reducing these levels significantly. When these products are applied, the bacterial load (and esp. the Vibrio load) will decrease +/- 10000 x ending up in levels of 100-1000 Vibrio sp per ml.
Marleen Dehasque, Inve Aquaculture NV
e-mail: m.dehasque@inve.be
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COMMENTS 2:
Short term disinfection after enrichment with formaldehyde, glutaraldehyde and chloramine-T is not very effective and will not reduce the bacterial counts more than about 1 log unit. I think that disinfection during enrichment is more effective. Chloramine-T can be used during hatching with good results, but not during enrichment because it leads to oxidation of the lipids in the emulsion. I have been using DC Selco products from INVE which reduces the bacterial counts by 3-4 log ( to about 10E4 to 10E5 cfu/g Artemia). I think these bacterial levels are acceptable. It would be interesting to know if someone has an idea of what disinfectant is in the DC products which could then be used for other enrichment diets.
I would be interested to know if someone has tried PREFURAN from ARGENT to suppress bacterial counts in Artemia or perhaps treated larvae with it.
Arnar Jonsson
e-mail: fiskeyhj@est.is