以粉核油球藻(Pinguiococcus pyrenoidosus CCMP 2078)为实验材料,在氮含量相同的条件下,采用NaNO_3、NH_4Cl、NaNO_3和NH_4Cl、NH_4NO_3和NH₂CONH₂五种氮源形式,研究其对该藻生长、脂肪酸组成、多不饱和脂肪酸(polyunsaturated fatty acids,PUFAs)和二十碳五烯酸(eicosapentaenoic acid,EPA)含量的影响。结果表明,相同氮浓度条件下,氮源对粉核油球藻CCMP 2078的生长有极显著的影响。以NH₂CONH₂为氮源,生长末期的细胞密度最高,为8×10~6 cells/mL;以NaNO_3和NH_4Cl为氮源的细胞密度比以NH_4NO_3为氮源的高;单独以NaNO_3或NH_4Cl为氮源时,该藻生长缓慢,细胞密度较低。该藻在不同氮源条件下的脂肪酸组成不同,但C14:0、C16:0和EPA始终是其主要的脂肪酸;以NaNO_3为氮源,PUFAs含量最高,占总脂肪酸的24.27%;以NH_4NO_3为氮源时,EPA含量最高,占总脂肪酸的12.93%。

In this paper,the effects of five kinds of nitrogen source including NaNO_3,NH_4Cl,NaNO_3 and NH_4Cl,NH_4NO_3 and NH₂CONH₂ on the growth,fatty acid composition and EPA content of P.pyrenoidosus CCMP 2078 was studied.The results showed that the nitrogen source had significant influence on the growth of P.pyrenoidosus CCMP 2078.The highest cell density 8×10~6 cells/mL was obtained when cultured with NH₂CONH2,while the cell density in the mixture of NaNO_3 and NH_4Cl was higher than that in NH_4NO_3.With very low cell density,the growth was very slow either in NaNO_3 or NH_4Cl.The fatty acid composition was different under different nitrogen source conditions.However,the majority fatty acid were C14:0,C16:0 and EPA(C20:5).The highest PUFAs content was 24.27%when used NaNO_3 as nitrogen source,while the highest EPA content obtained was 12.93%when used NH_4NO_3 as nitrogen source.