Heart Healthy Microalgae? Algal production of TAGs with high levels of PUFAs

描述(由申请人提供)：美国心脏协会和欧洲心脏病学会建议饮食中多不饱和脂肪酸(PUFAs)的摄入量为1g/d，以预防冠心病。人类饮食中多不饱和脂肪酸的来源主要来自鱼和鱼油。不幸的是，这些天然来源可能会因毒素的生物积累而受到损害；此外，衍生油中的脂肪酸(FAs)的组成也会受到影响 多不饱和脂肪酸的含量并不总是很高。可悲的是，仅靠野生渔业的减少并不能满足不断增长的人口对饮食的需求。微藻是包括脂肪酸在内的各种有益代谢物的来源。它们能够合成和积累多不饱和脂肪酸，为饮食需求提供了替代来源。油性微藻以其不同的脂肪生产能力而闻名，干湿法可积累高达67%的脂肪。培养富含多不饱和脂肪酸的微藻是膳食中omega-3脂肪酸的潜在来源。在目标1中，我们确定了环境条件对多不饱和脂肪酸合成和初级代谢物库的影响。我们将量化含油微藻N.Salina在冷胁迫和营养胁迫下生长时产生的脂肪的丰度和特定的FA组成。微藻对不同环境条件的适应性不仅直接影响生长和产量，而且对脂肪的产生和组成具有决定性作用。在目标2中，我们将通过使用FT-ICR MS进行详细的成分分析来确定完整的脂体。这些结果将识别富含多不饱和脂肪酸侧链的脂类。我们还将确定非生物环境胁迫如何影响和重塑脂质类别和代谢池，促进多不饱和脂肪酸的合成，这些多不饱和脂肪酸被隔离为三酰甘油(TAG)的合成和积累。在这项试点提案的结论中，我们将有关于非生物胁迫对总多不饱和脂肪酸积累的作用以及支持碳通量向其合成的代谢重新分配的新信息。其次，我们确定了其他脂类物种在重塑和提供高度不饱和脂肪酸以支持富含多不饱和脂肪酸的Tag从头合成中所起的作用。藻类养殖非常适合于西南荒漠地区，特别是海藻，可以利用非耕地和盐碱地含水层。种植富含多不饱和脂肪酸的微藻是膳食中omega-3脂肪酸的潜在来源，可广泛和经济地用于预防美国西南部以营养为基础的健康差距。

DESCRIPTION (provided by applicant): The American Heart association and the European Society of Cardiology recommend a dietary consumption of polyunsaturated fatty acids (PUFAs) at 1 g/d for the prevention of coronary heart disease. Human dietary sources of PUFAs are mainly derived from fish and fish oil. Unfortunately these natural sources may be compromised with the bioaccumulation of toxins; further the composition of fatty acids (FAs) in the derived oil are not consistent and may not always be high in PUFAs. Sadly declining wild fisheries alone will not fulfill the demand for the dietary requirements from a growing human population. Microalgae are sources of a variety of beneficial metabolites including FAs. They are capable of synthesizing and accumulating PUFAs providing an alternate source for dietary requirements. Oleaginous microalgae are known for their varying lipid productivity and can accumulate up to ~67% lipid by dry wt. Cultivation of microalgae rich in PUFAs is a potential source of dietary omega-3 FAs. In Aim 1 we determine the effect of environmental conditions on PUFA synthesis and primary metabolite pools. We will quantify the abundance and specific FA composition of lipid produced by the oleaginous microalgae N. salina when grown under cold stress & nutrient stress. Adaptability of microalgae to varying environmental conditions does not only directly affect growth and yield but has a determining role on lipid production and composition. In Aim 2 we will determine the complete lipidome by a detailed compositional analysis using FT-ICR MS. These results will identify lipid classes enriched in PUFAs side chains. We will also determine how lipid classes and metabolic pools are influenced and remodeled by abiotic environmental stress promoting the synthesis of PUFAs that are sequestered into triacylglycerol (TAG) synthesis and accumulation. At the conclusion of this pilot proposal, we will have new information on the roles of abiotic stress on total PUFA accumulation and the metabolic reallocation that supports carbon flux towards their synthesis. Secondly we identify the role that other lipid species play in remodeling and providing highly unsaturated FAs to support the de novo synthesis of TAG rich in PUFA. Algae cultivation is well suited to the desert southwest, especially marine algae, which can use the non-arable land and saline aquifers. The cultivation of microalgae rich in PUFAs is a potential source of dietary omega-3 FAs which can be broadly and economically available for the prevention of nutritionally-based health disparities in the southwestern United States.