Species-specific differences in long-chain n-3 essential fatty acid, sterol, and steroidal ketone production in six heterotrophic protist species
Species-specific differences in long-chain n-3 essential fatty acid, sterol, and steroidal ketone production in six heterotrophic protist species
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六种异养原生生物物种长链 n-3 必需脂肪酸、甾醇和甾酮生产的物种特异性差异
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
E. Harvey
中科院分区：
文献类型：
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作者：
F. Chu;E. Lund;Paul R. Littreal;Kate Ruck;E. Harvey
研究了6种异养原生生物产生长链n-3必需脂肪酸（LCn-3EFA）、甾醇和甾酮的能力及其种属差异：3种有鞘甲藻（Cryptoperidiniopsis brodyi、Pfiesteria piscicida和Luciella masanensis）、1种无鞘甲藻（Amphidinium longum）、1种草食纤毛虫（Strombidinopsis sp.）和1种食菌纤毛虫（Uronema sp.）给它们喂食藻类（Rhodium salina或Dunaliella tertiolecta）或细菌。3种囊藻甾醇不能转化为其它常见甾醇。相反，它们产生甾醇和甾体酮，如甲藻甾醇、甲藻甾烷醇、甲藻甾酮和甲藻甾烷酮，这些物质通常在自养甲藻中发现。salina或D.这两种都不包含它们。助理longum，拟龙螺Strombidinopsis sp.，和尾丝藻属不能将膳食甾醇生物转化为其它甾醇或产生甾醇和甾酮。Pfiesteria piscicida和L. masanensis生长在LCn-3EFA缺陷型的p53上。tertiolecta和Uronema sp.能够产生长链n-3多不饱和脂肪酸二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），这是高营养级生物体所必需的。Uronema sp.的细菌猎物缺乏EPA，DHA和LCn-3EFA前体。虽然3种囊状甲藻产生的甾醇和甾酮的营养价值尚不清楚，但其中2种甲藻和食菌纤毛虫产生的EPA和DHA的贡献值得注意。为了进一步了解异养原生生物的中间作用及其在浮游食物网中的营养贡献，有必要研究更多的物种，特别是新发现和分离的物种。
We investigated the capability and species-specific differences in long-chain n-3 essential fatty acid (LCn-3EFA), sterol, and steroidal ketone production of 6 heterotrophic protists: 3 thecate dinoflagellates (Cryptoperidiniopsis brodyi, Pfiesteria piscicida, and Luciella masanensis), 1 athecate dinoflagellate (Amphidinium longum), 1 herbivorous ciliate (Strombidinopsis sp.), and 1 bacterivorous ciliate (Uronema sp.) by feeding them algae (Rhodomonas salina or Dunaliella tertiolecta) or bacteria. The 3 thecate species did not convert algal sterols to other usual and common sterols. Instead, they produced sterols and steroidal ketones, such as dinosterol, dinostanol, dinosterone, and dinostanone, usually found in autotrophic dinoflagellates when fed R. salina or D. tertiolecta, both of which do not contain them. The A. longum, Strombidinopsis sp., and Uronema sp. did not bioconvert dietary sterols to other sterols or produce sterols and steroidal ketones. Pfiesteria piscicida and L. masanensis grown on the LCn-3EFA-deficient alga D. tertiolecta and Uronema sp. were capable of producing the long-chain n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential for organisms at higher trophic levels. The bacterial prey of Uronema sp. lacked EPA, DHA, and LCn-3EFA precursors. Although the nutritional values of the sterols and steroidal ketones produced by the 3 thecate dinoflagellates are not known, the contribution of EPA and DHA by 2 of them and the bacterivorous ciliate are noteworthy. To further understand the intermediate roles of heterotrophic protists and their essential nutrient contribution in planktonic food webs, it is necessary to examine more species, particularly those newly discovered and isolated.