Data/hora: 01/06/2024 04:37:28

Provedor de dados: 	27	
País: 	Belgium	
Título: 	Variation of ascorbic acid content in different live food organisms	
Autores: 	Merchie, G.; Lavens, P.; Dhert, Ph.; Dehasque, M.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.	
Data: 	1995	
Ano: 	1995	
Resumo: 	Ascorbic acid (AA) is an essential nutrient in particle and live aquafeeds. In order to better assess the needs for this nutrient during larviculture the AA content of algae, rotifers and &lt;i&gt;Artemia&lt;/i&gt; was studied with respect to their suitability at startfeeding. In general, the microalgae evaluated were rich in AA (1000-4000 µgAA/gDW), but showed a considerable variability among the different species: e.g. the concentration in &lt;i&gt;Isochrysis&lt;/i&gt; and&lt;i&gt;Chlorella&lt;/i&gt; reached values 3-to 4-fold the percentage of &lt;i&gt;Tetraselmis&lt;/i&gt; (0.11% of DW). &lt;i&gt;Brachionus&lt;/i&gt; routinely cultured on &lt;i&gt;Chlorella&lt;/i&gt; contained 2300 µg AA/gDW. Cysts of various batches and strains of &lt;i&gt;Artemia&lt;/i&gt; differed considerably in ascorbic acid-2-sulphate (AAS) concentration (296-517 µgAA/gDW). The amount of AA available in the freshly-hatched nauplii reflected exactly the AAS reserve present in the cysts, what evidences the complete conversion of AAS to free AA during completion of embryonic development into nauplii. Boosting techniques both for &lt;i&gt;Brachionus&lt;/i&gt; and &lt;i&gt;Artemia&lt;/i&gt; using ascorbyl palmitate (AP) as the vitamin C source were established. The addition of 20% AP in the diet of &lt;i&gt;Brachionus&lt;/i&gt; enhanced their AA content 10-fold over 3 days of culture. Supplementation of the enrichment emulsion for &lt;i&gt;Artemia&lt;/i&gt; with 20% AP increased the AA content up to 2000 µg/gDW after 24h enrichment. This lipophilic derivative of AA appeared to be a stable form of vitamin C for enhancing AA levels in the live diets during culture and/or enrichment. This bioencapsulated method provides a tool for hatcheries to build up high AA concentrations in the live prey administered to first feeding larvae of aquaculture organisms in case of specific requirements (e.g. with respect to handling stress, deformities). A survey of commercial hatcheries indicated that a wide range of products is used for the cultivation and boosting of rotifers, which consequently affect their AA levels. In general, the AA content in the algae and, consequently, the algal enrichment of &lt;i&gt;Brachionus&lt;/i&gt; tended to score lower in the hatcheries than under lab conditions.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2578	
Fonte: 	%3Ci%3EAquaculture+134%3C%2Fi%3E%3A+325-337	
Fonte: 	info:eu-repo/semantics/restrictedAccess