Background Omega-3 fatty acids have various health benefits in combating against neurological problems, cancers, cardiac problems and hypertriglyceridemia. The main dietary omega-3 fatty acids are obtained from marine fish. Due to the pollution of marine environment, recently microalgae are considered as the promising source for the omega-3 fatty acid production. However, the demand and high production cost associated with microalgal biomass make it necessary to implement novel strategies in improving the biomass and omega-3 fatty acids from microalgae. Results Four plant hormones zeatin, indole acetic acid (IAA), gibberellic acid (GBA) and abscisic acid (ABA) were investigated for their effect on the production of biomass and lipid in isolated Chlorella sp. The cells showed an increase of the biomass and lipid content after treatments with the plant hormones where the highest stimulatory effect was observed in ABA-treated cells. On the other hand, IAA showed the highest stimulatory effect on the omega-3 fatty acids content, eicosapentaenoic acid (EPA) (23.25%) and docosahexaenoic acid (DHA) (26.06%). On the other hand, cells treated with ABA had highest lipid content suitable for the biodiesel applications. The determination of ROS markers, antioxidant enzymes, and fatty acid biosynthesis genes after plant hormones treatment helped elucidate the mechanism underlying the improvement in biomass, lipid content and omega-3 fatty acids. All four plant hormones upregulated the fatty acid biosynthesis genes, whereas IAA particularly increased omega-3-fatty acids as a result of the upregulation of omega-3 fatty acid desaturase. Conclusions The contents of omega-3 fatty acids, the clinically important compounds, were considerably improved in IAA-treated cells. The highest lipid content obtained from ABA-treated biomass can be used for biodiesel application according to its biodiesel properties. The EPA and DHA enriched ethyl esters are an approved form of omega-3 fatty acids by US Food and Drug Administration (FDA) which can be utilized as the therapeutic treatment for the severe hypertriglyceridemia.

中文翻译：

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植物激素诱导的小球藻富集。omega-3 脂肪酸。

背景 Omega-3 脂肪酸在对抗神经问题、癌症、心脏问题和高甘油三酯血症方面具有多种健康益处。主要的膳食 omega-3 脂肪酸来自海鱼。由于海洋环境的污染，最近微藻被认为是生产omega-3脂肪酸的有希望的来源。然而，与微藻生物质相关的需求和高生产成本使得有必要实施新的策略来改善微藻的生物质和 omega-3 脂肪酸。结果研究了四种植物激素玉米素、吲哚乙酸（IAA）、赤霉酸（GBA）和脱落酸（ABA）对分离的小球藻生物量和脂质产生的影响。在用植物激素处理后，细胞显示出生物量和脂质含量的增加，其中在 ABA 处理的细胞中观察到最高的刺激作用。另一方面，IAA 对 omega-3 脂肪酸含量的刺激作用最高，即二十碳五烯酸 (EPA) (23.25%) 和二十二碳六烯酸 (DHA) (26.06%)。另一方面，用 ABA 处理的细胞具有最高的适合生物柴油应用的脂质含量。植物激素处理后 ROS 标记、抗氧化酶和脂肪酸生物合成基因的测定有助于阐明生物量、脂质含量和 omega-3 脂肪酸改善的机制。所有四种植物激素上调脂肪酸生物合成基因，而由于 omega-3 脂肪酸去饱和酶的上调，IAA 特别增加了 omega-3-脂肪酸。结论 在 IAA 处理的细胞中，临床上重要的化合物 omega-3 脂肪酸的含量显着提高。根据其生物柴油特性，从 ABA 处理的生物质中获得的最高脂质含量可用于生物柴油应用。富含 EPA 和 DHA 的乙酯是美国食品和药物管理局 (FDA) 批准的 omega-3 脂肪酸形式，可用作严重高甘油三酯血症的治疗方法。根据其生物柴油特性，从 ABA 处理的生物质中获得的最高脂质含量可用于生物柴油应用。富含 EPA 和 DHA 的乙酯是美国食品和药物管理局 (FDA) 批准的 omega-3 脂肪酸形式，可用作严重高甘油三酯血症的治疗方法。根据其生物柴油特性，从 ABA 处理的生物质中获得的最高脂质含量可用于生物柴油应用。富含 EPA 和 DHA 的乙酯是美国食品和药物管理局 (FDA) 批准的 omega-3 脂肪酸形式，可用作严重高甘油三酯血症的治疗方法。