The importance of highly unsaturated fatty acids in zooplankton nutrition: evidence from experiments with Daphnia, a cyanobacterium and lipid emulsions
The importance of highly unsaturated fatty acids in zooplankton nutrition: evidence from experiments with Daphnia, a cyanobacterium and lipid emulsions
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DOI：
10.1046/j.1365-2427.1997.00222.x
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发表时间：
1997-12-01
影响因子：
2.7
通讯作者：
Muller-Navarra, DC
中科院分区：
文献类型：
--
作者：
DeMott, WR;Muller-Navarra, DC
1.我们使用实验室生长和喂养实验来评估欧米伽3高度不饱和脂肪酸（HUFA）在浮游动物营养中的作用。多不饱和脂肪酸（PUFA）在绿色藻中占总脂肪酸的40%，而在蓝藻细长聚球藻中仅占6%。栅藻含有适量的ω 3 HUFA二十碳五烯酸（EPA，20：5 ω 3）和二十二碳六烯酸（DHA，22：6 ω 3），而聚球藻只含有微量的EPA，没有DHA。一天大的水蚤在聚球藻的饮食上保持了2-3天的高生长率，但在6天或7天的实验后期表现出生长减缓甚至体重减轻。大型蚤生长优于D. galeata或D.以纯聚球藻为食在相同浓度（0.5 mgC l（-1））的绿色藻或绿色藻与聚球藻的混合物中，水蚤均能保持较高的生长速率.补充聚球藻与鱼油乳液富含欧米茄3 HUFA显着改善所有三种水蚤的生长和繁殖。然而，补充单不饱和油酸（18：1 ω 9）的乳剂并不影响D。galeata的生长，并导致D. magna.4.短期（7分钟）和长期（3小时）喂养试验与C-14-标记聚球藻被用来评估驯化和混合饲料对碳掺入的影响。D.与用栅藻驯化或饲喂聚球藻和栅藻混合物的动物相比，饲喂未标记聚球藻3天的galeata的清除率没有下降，但碳掺入显著下降。我们的研究结果支持的假设，蓝细菌的营养质量差，至少部分是由于HUFA缺乏。生长和喂养实验都表明，利用聚球藻是提高HUFA从脂质储备或混合饮食。
1. We used laboratory growth and feeding experiments to evaluate the role of omega 3 highly unsaturated fatty acids (HUFA) in zooplankton nutrition. Polyunsaturated fatty acids (PUFA) comprised 40% of total fatty acids (FA) in the green alga Scenedesmus acutus but only 6% in the cyanobacterium Synechococcus elongatus. Scenedesmus contained modest amounts of the omega 3 HUFA eicosapentaenoic acid (EPA, 20:5 omega 3) and docosahexaenoic acid (DHA, 22:6 omega 3), whereas Synechococcus contained only a trace of EPA and no DHA.2. One-day-old Daphnia maintained high growth rates for 2-3 days on a diet of Synechococcus but exhibited reduced growth or even lost weight over the later part of the 6- or 7-day experiments. Daphnia magna grew better than D. galeata or D. pulicaria on a diet of pure Synechococcus. Daphnids fed the same concentration (0.5 mgC l(-1)) of green algae or a mixture of green algae and Synechococcus maintained high growth rates.3. Supplementing Synechococcus with fish oil emulsions rich in omega 3 HUFA markedly improved the growth and reproduction of all three Daphnia species. Supplementation with an emulsion of monounsaturated oleic add (18: 1 omega 9), however, did not affect the growth of D. galeata and caused a decrease in the growth of D. magna.4. Short-term (7 min) and long-term (3 h) feeding trials with C-14-labelled Synechococcus were used to evaluate the effects of acclimation and mixed diets on carbon incorporation. D. galeata that had fed on unlabelled Synechococcus for 3 days exhibited no decline in clearance rate but a marked decline in carbon incorporation in comparison with animals acclimated with Scenedesmus or fed a mixture of Synechococcus and Scenedesmus.5. Our results support the hypothesis that the poor nutritional quality of a cyanobacterium is at least partially due to a HUFA deficiency. Growth and feeding experiments both suggest that the utilization of Synechococcus is enhanced by HUFA from lipid reserves or a mixed diet.