Potential of using Daphnia
magna (crustacea) developing in an aerated waste stabilisation pond as a
commercial source of chitin
H.-M.
Cauchie, M.-F. Jaspar-Versali, L. Hoffmann, J.-P. Thomé-2002
Aquaculture, 205(1-2): 103-117
Abstract :
The potential of using the planktonic crustacean Daphnia
magna as a commercial source of chitin was studied on the basis of the
estimation of the amount of chitin produced annually by this species and the
specifications of this kind of chitin. D. magna was found to have a
significant chitin content, ranging from 3% to 7% of the body dry weight.
During three consecutive years, chitin biomass (B) and daily somatic
chitin production (daily PSOM) were monitored in a
59,000-m2 aerated waste stabilisation pond located in the
Grand-Duchy of Luxembourg (Western Europe). These variables were found to
vary a lot seasonally. Maximum values were observed in summer (B>40
kg chitin; daily PSOM>20 kg chitin/day). Annual somatic
chitin production reached on average 1200 kg chitin/year. The amount of
chitin generated by the moulting of the daphnids (i.e. chitin contained in
the exuviae) can also constitute a significant source of chitin, reaching
about 1220 kg chitin/year. Chitin was isolated from D. magna,
following three different processing routes. The specifications of the
isolated and purified chitin were similar to those of commercial chitin
extracted from crabs and shrimps. The average molecular weight varied from
600,000 to 2,600,000 depending on the processing route. The isolated chitin
had a low N content indicating a high degree of acetylation.
(Institute of Zoology, University of Liège, Quai Van
Beneden 22, B-4020 Liège, Belgium, Tel.: +352-47-02-61-430; fax:
+352-47-02-61-389, e-mail : cauchie@crpgl.lu)