|
|
|
| Registros recuperados: 18 | |
|
| |
|
|
| Huo, J.-Z.; Nelis, H.; Lavens, P.; Sorgeloos, P.; De Leenheer, A.P.. |
| A liquid chromatographic (HPLC) method has been developed for the quantitative determination of different forms of vitamin E (alpha-, gamma-, and delta-tocopherol) in aquatic organisms. The assay consists of a simple extraction with methanol containing butylhydroxytoluene (BHT) as an antioxidant, followed by reversed phase chromatography with fluorescence detection. The efficiency of the extraction method was equivalent or superior to that of more complex approaches for the isolation of tocopherols. Linearity has been achieved over the range of 0.02 to 3 µg/ml for alpha-tocopherol and within-run and between-run coefficients of variation at three levels were 0.7-2.9 and 1.2-3.7%, respectively. The recovery at three concentrations ranged from 73.8 to 96.6%... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2978 |
| |
|
|
| Merchie, G.; Lavens, P.; Dhert, Ph.; Garcia Ulloa Gómez, M.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| The effect of the high ascorbic acid (AA) levels transferred through enriched live food was evaluated for turbot <i>Scophthalmus maximus</i> larvae in two consecutive feeding experiments. The same feeding strategy was applied to all treatments, except for the AA content in the live food which was manipulated through bioencapsulation with ascorbyl palmitate. This resulted finally in a low, medium and high-AA treatment. The AA incorporation levels in the turbot larvae (up to 1400 µg AA g DW<sup>-1</sup>) were correlated with the AA content of the live food administered. However, feeding the high AA concentration resulted in the same values as for the medium treatment, indicating a saturation of the body AA reserves. Under standard... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3022 |
| |
|
|
| Gapasin, R.S.J.; Nelis, H.; Chair, M.; Sorgeloos, P.. |
| Assimilation levels of the antibacterials trimethoprim (TMP) and sulfamethoxazole (SMX) in sea bass (<i>Dicentrarchus labrax</i>) fry tissue administered orally were investigated. A 1:5 TMP and SMX combination incorporated in oil emulsion (Selco) at 20% and 40% concentrations (w/w) were bioencapsulated in <i>Artemia</i> (Instar II) nauplii. Chemotherapeutics-loaded ('medicated') nauplii were fed to the sea bass fry and drug concentration in the tissue were analysed by high-performance liquid chromatography (HPLC). Fish fed 40% 'medicated' <i>Artemia</i> assimilated significantly higher levels of chemotherapeutics compared with those fed 20% 'medicated' <i>Artemia</i> . Chemotherapeutics given at 40% reached... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dicentrarchus labrax (Linnaeus; 1758) [Bass]. |
| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2964 |
| |
|
|
| Merchie, G.; Lavens, P.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| A study was undertaken to upgrade the levels of vitamin C in <i>Artemia</i> and <i>Brachionus</i> through bioencapsulation and to investigate in this way the requirements for ascorbic acid (AA) during larviculture of fish and prawn. Ascorbyl palmitate (AP) was used as the vit C source because of its stable and lipophylic characteristics which allowed its incorporation in booster emulsions and its readily conversion into AA by <i>Brachionus</i> and <i>Artemia</i> . Under standard conditions very high levels of AA could be incorporated into the <i>Artemia</i> nauplii: supplementation of the enrichment emulsion with 20% AP (w/w) increased the AA-content up to 2000 ppm after 24h enrichment. Also in... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2743 |
| |
|
|
| Merchie, G.; Lavens, P.; Radull, J.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| The effects of high levels of ascorbic acid (AA) delivered through enriched live food has been verified through the successful culture of larval giant freshwater prawn, <i>Macrobrachium rosenbergii</i> Two successive feeding trials were set up using a control (550 µg AA g<sup>-1</sup> DW) and two different AA-enrichment levels in <i>Artemia</i> (1300 and 2750 µg AA g<sup>-1</sup> DW). Under standard culture conditions, no differences in growth nor survival could be observed demonstrating that the nutritional requirements are below 550 µg AA g<sup>-1</sup> DW, which is the normal level occurring in freshly-hatched <i>Artemia</i> . However, a significantly positive effect could be... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2582 |
| |
|
| |
|
|
| Kontara, E.K.M.; Merchie, G.; Lavens, P.; Robles, R.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| L-ascorbyl-2-polyphosphate (ApP) was used as a vitamin C source to study the ascorbic acid (AA) requirements for the early postlarval stages of white shrimp (<i>Penaeus vannamei</i>). First the stability of ApP in the diets was determined: ApP losses after pelletizing and 10 min immersion in seawater were 25-35% and 30%, respectively. Semipurified diets with five levels of ApP (0, 20, 40, 100 and 200 mg kg<sup>-1</sup> expressed as active AA were fed <i>ad libitum</i> to <i>P. vannamei</i> (PL-14 stage, mean dry weight 0.73 mg) for 26 days. Each treatment was run in five replicates. No significant differences in growth were observed among treatments after 26 days of feeding. As of day 19 of feeding, increased... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diets; Polyunsaturated fatty acids; Shrimp culture; Penaeus vannamei. |
| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2959 |
| |
|
|
| Merchie, G.; Lavens, P.; Storch, V.; Übel, U.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| Stable forms of vitamin C were verified as dietary sources of ascorbic acid (AA) for the nursery stages of European sea bass and turbot. In a first experiment, various concentrations of ascorbyl palmitate (AP) and one level of AA 2-polyphosphate (ApP) were evaluated in a semi purified diet for European sea bass, <i>Dicentrarchus labrax</i>. A significantly lower AA concentration was detected in the fry fed the AP-supplemented diets compared to the ApP-fed group, providing evidence that AP is an inferior source of vitamin C for young stages of sea bass. ApP was subsequently selected for the determination of the AA requirements of both sea bass and turbot (<i>Scophthalmus maximus</i>) fry. The AA levels incorporated in the body... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dicentrarchus labrax (Linnaeus; 1758) [Bass] Scophthalmus maximus (Linneaus; 1758). |
| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3045 |
| |
|
|
| Nelis, H.; Léger, P.; Sorgeloos, P.; De Leenheer, A.P.. |
| The brine shrimp <i>Artemia</i> , an excellent live food source in aquaculture, has been studied as a carrier to deliver selected chemotherapeutic agents to fish for prophylactic treatment of infectious diseases. To monitor the efficiency of incorporation of trimethoprim and sulfamethoxazole in <i><i>Artemia</i> franciscana</i>, a sensitive and specific analytical method was developed. It is based on homogenization of <i>Artemia</i> nauplii in methanol, extraction of lipids with hexane, solid-phase cleanup on C<sub>18</sub> cartridges, and reversed-phase liquid chromatography with detection at 210 nm. The method is sensitive (detection limit, on the order of 3 µg/g with a sample quantity of 30 mg... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquaculture techniques; Fish culture; Infectious diseases; Medicine; Artemia. |
| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262329.pdf |
| |
|
| |
|
|
| Merchie, G.; Lavens, P.; Dhert, Ph.; Pector, R.; Mai Soni, A.F.; Nelis, H.; Ollevier, F.P.; De Leenheer, A.P.; Sorgeloos, P.. |
| Live food enrichment techniques, using formulated diets and emulsions for improving the nutritional quality of <i>Brachionus</i> and <i>Artemia</i> , were studied as a tool for transferring ascorbic acid (AA) to fish larvae. <i>Artemia</i> nauplii enriched for 24h with an experimental emulsion containing 20% HUFA and 0%, 10% and 20% ascorbyl palmitate (AP) were administered to catfish larvae in a 20-day feeding trial. Survival was not affected by the dietary AA, but from day 7 onwards a significantly positive effect of supplemental AA on growth was demonstrated. At the end of the experiment the 20% AP group weighed 30% more than the control (0% AP), i.e. 9.5 and 6.3mg DW, respectively. Evaluation of the physiological... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clarias gariepinus Dicentrarchus labrax (Linnaeus; 1758) [Bass]. |
| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2581 |
| |
|
| |
|
| |
|
|
| Nelis, H.; Lavens, P.; Sorgeloos, P.; Van Steenberge, M.; De Leenheer, A.P.. |
| The carotenoid composition of <i>Artemia</i> cysts from 17 geographical strains was studied. All-<i>trans</i>-canthaxanthins and <i>cis</i>-canthaxanthins were quantitatively determined using a non-aqueous reversed phase chromatographic method. In dehydrated cysts, the average <i>cis</i>- and <i>trans</i>-canthaxanthin levels (+/- SD) were 152 +/- 52 and 134 +/- 42 µg/g, respectively (range 38-227 and 67-201µg/g). The corresponding concentrations in hydrated cysts were (<i>cis</i>) 177 +/- 60 µg/g (range 47-271 µg/g) and (<i>trans</i>) 112 +/- 35 µg/g (range 52-169 µg/g). The <i>cis/trans</i> concentration ratios averaged 1.13 (range 0.57-1.47) and 1.60 (range... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3196 |
| |
|
|
| Huo, J.-Z.; Nelis, H.; Lavens, P.; Sorgeloos, P.; De Leenheer, A.P.. |
| In aquaculture, alpha-tocopheryl acetate (alpha-TA) is the main source of vitamin E used to fortify fish feed. Alpha-TA in fish is often determined indirectly, i.e. by alkaline hydrolysis, followed by quantitation of ‘total alpha-tocopherol’ (alpha-T) and substraction of the natively present alpha-T. The aim of this study was to develop an HPLC method for the simultaneous quantitative determination of alpha-TA and free tocopherols in aquatic organisms and fish feed. The assay consists of a simple extraction with methanol containing butylhydroxytoluene (BHT) as an antioxidant, followed by reversed-phase chromatography with consecutive UV and fluorescence detection of alpha-TA and tocopherols, respectively. The peak of the internal standard tocol in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vitamin E; Vitamins. |
| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=4020 |
| |
|
|
| Merchie, G.; Lavens, P.; Verreth, J.; Ollevier, F.P.; Nelis, H.; De Leenheer, A.P.; Storch, V.; Sorgeloos, P.. |
| The effect of three dietary ascorbic acid (AA) concentrations, each applied via two feed types, on production characteristics and physiological condition of African catfish (<i>Clarius gariepinus</i>) larvae has been assessed in two 10-day culture trials. Three treatments received only <i>Artemia</i> nauplii enriched with an experimental emulsion containing 0, 10 or 20% ascorbyl palmitate (AP) and yielding 530, 1200 and 1600 µg AA g<sup>-1</sup> DW <i>Artemia</i> , respectively; the other three treatments were fed the same <i>Artemia</i> diets which were partially substituted by an artificial diet containing no vitamin C (ratio 20:80). No differences in survival could be observed: however, from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish larvae; Food organisms; Vitamin C; Clarias gariepinus. |
| Ano: 1997 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2963 |
| |
|
|
| Merchie, G.; Lavens, P.; Dhert, Ph.; Dehasque, M.; Nelis, H.; De Leenheer, A.P.; Sorgeloos, P.. |
| 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 <i>Artemia</i> 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 <i>Isochrysis</i> and<i>Chlorella</i> reached values 3-to 4-fold the percentage of <i>Tetraselmis</i> (0.11% of DW). <i>Brachionus</i> routinely cultured on <i>Chlorella</i> contained 2300 µg AA/gDW. Cysts of various batches and strains of... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2578 |
| |
| Registros recuperados: 18 | |
|
|
|
