Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum
Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum
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DOI：
10.1007/s00449-016-1589-6
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发表时间：
2016-03
影响因子：
3.8
通讯作者：
Gaomin Su;Kailin Jiao;Zheng Li;Xiaoyi Guo;Jingyu Chang;Theoneste Ndikubwimana;Yong Sun;Xianhai Zeng;Yinghua Lu;Lu Lin
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文献类型：
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作者：
Gaomin Su;Kailin Jiao;Zheng Li;Xiaoyi Guo;Jingyu Chang;Theoneste Ndikubwimana;Yong Sun;Xianhai Zeng;Yinghua Lu;Lu Lin
多不饱和脂肪酸(PUFAs)对人体健康和水产养殖具有重要的营养价值。系统研究了碳酸氢钠(0.04~1.2g/L)、温度(25℃、30℃、33℃)和磷酸盐(0.00~0.14 mg/L)对红豆杉生物量、总脂肪酸和花生四烯酸积累的影响。NaHCO3用量为0.8 mg/L，中温30℃为佳。此外，适量的磷酸盐能显著提高总脂肪酸和花生四烯酸的产量，当磷浓度为666.38 mg/L和159.74 mg/L时，总脂肪酸和花生四烯酸的产量最高。有趣的是，随着磷酸盐浓度的继续下降，不饱和脂肪酸/总脂肪酸和花生四烯酸的比值也相应增加，表明磷限制促进了不饱和脂肪酸和花生四烯酸的合成。低浓度的磷酸盐有利于提高不饱和脂肪酸6-脱饱和酶的活性，该酶在催化C16：0转化为C18：2过程中起关键作用，从而提高了∆的选择性。同时，ω-6途径的促进和∆17-去饱和酶活性的抑制以及磷酸限制可能是提高ARA选择性的原因之一。磷限制策略促进了不饱和脂肪酸和ARA的生物合成。可用于ARA的工业化生产和商业化生产。
Polyunsaturated fatty acids (PUFAs) are highly appreciated on their nutritive value for human health and aquaculture.P. purpureum, one of the red microalgae acknowledged as a promising accumulator of ARA, was chosen as the target algae in the present research. Effects of sodium bicarbonate (0.04–1.2 g/L), temperature (25, 30 and 33 °C) and phosphate (0.00–0.14 g/L) on biomass yield, total fatty acids (TFA) and arachidonic acid (ARA) accumulation were investigated systemically. NaHCO3dose of 0.8 g/L and moderate temperature of 30 °C were preferred. In addition, TFA and ARA production were significantly enhanced by an appropriate concentration of phosphate, and the highest TFA yield of 666.38 mg/L and ARA yield of 159.74 mg/L were obtained at a phosphate concentration of 0.035 g/L. Interestingly, with phosphate concentration continuing to fall, UFA/TFA and ARA/EPA ratios were increased accordingly, suggesting that phosphate limitation promoted unsaturated fatty acids and arachidonic acid biosynthesis. Low concentration of phosphate may be favored to increase the enzymatic activities of ∆6-desaturase, which played a key role in catalyzing the conversion of C16:0 to C18:2, and thus the selectivity of UFA increased. Meanwhile, the increase of ARA selectivity could be attributed to ω6 pathway promotion and ∆17-desaturase activity inhibition with phosphate limitation. Phosphate limitation strategy enhanced unsaturated fatty acids and ARA biosynthesis inP. purpureum, and can be applied in commercial scale manufacturing and commercialization of ARA.