The effect of iron, manganese, phosphorus and nitrogen on growth and lipid synthesis of the microalgae Nannochloropsis oceanica CCMP1779, as well as their impact on the magnetic harvesting efficiency, are examined under their depriving cell culture conditions. Herein, it is demonstrated that nitrogen and manganese depletion primarily reduced cell growth while phosphorus and iron restriction led to higher dry biomass. Subsequently, the role of those nutrients on fatty acids profile was examined. Phosphorus and nitrogen restriction resulted in lower and higher lipid content, respectively. High amounts of polyunsaturated fatty acids like eicosapentaenoic acid are produced under iron and manganese depletion. Phosphorus deprivation favors monounsaturated fatty acids such as C18:1 and C16:1, while nitrogen restriction favors saturated fatty acid production like C14:0, C16:0 and C18:0. Since the presence/absence of macro- and micro-elements may affect the overall electrostatic charges on the outmost microalgae surface, it was also analyzed how these elements affect the magnetic harvesting efficiency. Results showed that phosphorus deprivation led to the best magnetic harvesting efficiency of N. oceanica cells (93%) as compared to other nutrient starvation as well as standard medium.

中文翻译：

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大量营养素和微量营养素对海洋拟南芥生长，脂肪酸组成和磁收效率的影响研究。

铁，锰，磷，氮对微藻拟南芥生长和脂质合成的影响在其剥夺细胞培养条件下检查了CCMP1779及其对磁收集效率的影响。在此，证明了氮和锰的消耗主要减少了细胞的生长，而磷和铁的限制导致了较高的干生物量。随后，检查了这些营养素对脂肪酸谱的作用。磷和氮的限制分别导致较低和较高的脂质含量。在铁和锰消耗下会产生大量的多不饱和脂肪酸，如二十碳五烯酸。缺磷有利于单不饱和脂肪酸，例如C18：1和C16：1，而氮限制有利于饱和脂肪酸的生产，例如C14：0，C16：0和C18：0。由于是否存在大量和微量元素可能会影响最外层微藻表面上的总体静电荷，因此还分析了这些元素如何影响磁收效率。结果表明，磷的缺乏导致最佳的磁收效率。与其他营养饥饿以及标准培养基相比，N。oceanica细胞（93％）。