为探索不同水平 N 和 P 对等鞭金藻(Isochrysis galbana Parke)产量及油脂品质的影响，在富 N(80. 00 mg·L^-1NO₃^--N)和无 N(0. 00 mg· L^-1NO₃^--N )条件下设置富 P 、 限 P 和 无 P(20. 00、0. 25 和0. 00 mg· L^-1 PO₄^3--P)共6 组培养基，对培养 10 d 时等鞭金藻的藻体质量浓度、P 吸收量、总脂肪酸质量分数和脂肪酸产率变化、13 个脂肪酸组分及其质量分数以及 EPA 和 DHA 的相对含量和产量进行了比较分析。 结果显示:在富 N 培养基中，等鞭金藻藻体质量浓度的增幅明显高于无 N 培养基且按培养基中 P 质量浓度从高到低依次降低。 总体上看，随培养时间延长，等鞭金藻的总脂肪酸质量分数持续升高，且在富 N 培养基中总脂肪酸质量分数高于无 N 培养基;其中，富 N 限P 和富 N 无 P 培养基中的总脂肪酸质量分数基本上均高于富 N 富 P 培养基。 富 N 培养基中各脂肪酸组分的质量分数大体上高于无 N 培养基，且限 P 培养基中各脂肪酸组分的质量分数大体上高于富 P 和无 P 培养基。 在富 N 富P 培养基中 1 L 藻体的 P 吸收量最高(0. 014 8 mg)，并且吸收的 P 绝大部分被贮存在藻体中，而在无 N 富 P 培养基中 P 吸收量明显降低(0. 009 8 mg)。 在富 N 富 P 培养基中，饱和脂肪酸质量分数和相对含量及 EPA 相对含量和产量均最低，但 DHA 相对含量和产量则最高。 在富 N 限 P 培养基中，等鞭金藻的 EPA 产量和脂肪酸产率均最高，其DHA 产量也较高；5 种优质脂肪酸组分(即 C18︰1n9c、C16︰0、C14︰0、C18︰0 和 C16︰1n9)的总相对含量达到 65. 86% ，尤其是 C18︰1n9c，其相对含量高达 28. 19% 。 综合分析结果显示:富 N 培养基有利于等鞭金藻的生长、P 吸收及脂肪酸积累，其中，富 N 限 P 培养基是等鞭金藻高产且产优质油脂的适宜培养基。 此外，等鞭金藻不但是生产生物柴油的优质资源而且是生产 DHA 和清除废水中 P 的潜在生物资源。

In order to explore the effects of phosphorus ( P) and nitrogen ( N) with different levels in medium on yield and oil quality of Isochrysis galbana Parke, six groups of media with P rich, P limited and P free (20. 00, 0. 25 and 0. 00 mg· L^-1 PO₄ ^3--P) under N rich (80. 00 mg· L^-1 NO₃ ^--N) and N free ( 0. 00 mg · L^-1 NO₃ ^--N ) conditions were set up, changes in algae mass concentration, P absorption, mass fraction of total fatty acids and productivity of fatty acids, thirteen fatty acid compositions and their mass fraction, and relative content and yield of EPA and DHA of I. galbana culturing for 10 d were compared and analyzed. The results show that in N rich medium, increasing range of algae mass concentration of I. galbana is obviously higher than that in N free medium, and decreases successively according to P mass concentration in medium from high to low. Overall, with prolonging of culture time, mass fraction of total fatty acids of I. galbana increases continuously, and that in N rich medium is higher than that in N free medium. In which, mass fraction of total fatty acids in N rich-P limited and N rich-P free media is basically higher than that in N rich-P rich medium. Mass fraction of different fatty acid compositions in N rich medium is generally higher than that in N free medium, and that in P limited medium is generally higher than that in P rich and P free media. P absorption of 1 Lalgae in N rich-P rich medium is the highest (0. 014 8 mg), and most of the absorbed P is stored , while P absorption in N free-P rich medium decreases obviously (0. 009 8 mg). In N rich-P rich medium, mass fraction and relative content of saturated fatty acids and relative content and yield of EPAall are the lowest, but relative content and yield of DHA are the highest. In N rich-P limited medium,yield of EPA and productivity of fatty acids of I. galbana are the highest, its DHA yield is also high;total relative content of five high quality fatty acid compositions including C18︰1n9c, C16︰0, C14︰0,C18︰0 and C16︰1n9 reaches 65. 86% , especially C18︰1n9c, its relative content is up to 28. 19% . The comprehensive analysis result indicates that N rich medium is beneficial to growth, P absorption and fatty acid accumulation of I. galbana, in which, N rich -P limited medium is the suitable medium for high yield and high quality oil of I. galbana. Otherwise, I. galbana is not only high quality resources for producing biodiesel but also potential biological resources for producing DHA and removing P in wastewater.