通过尼罗红荧光染色对一株富油微藻金藻Isochrysis sp. CCMM5001建立和完善了一种方便快捷且能准确定量金藻油脂含量的方法，利用该方法探索了不同培养条件对金藻生长和总脂积累的影响。结果表明：经尼罗红染色后，金藻的单细胞荧光强度与其总脂含量呈良好的线性关系；金藻最适生长的氮浓度、光照强度和温度分别为1323µmol/L、148.0µmol/(m2·s)、25℃；最适总脂积累的氮浓度、光照强度和温度分别为441µmol/L、92.5µmol/(m2·s)、15℃；优化培养条件并采用两阶段培养法后总脂含量和油脂产率都有大幅提高，可分别高达63.3%和22 mg/(L·d)。%Some species of microalgae are considered as an ideal resource for biodiesel production because they contain high level of lipids. The traditional method to quantify the lipids level includes the solvent extraction and gravimetric determination based on a chloroform-methanol-water system. This method has the disadvantage of being time consuming and inefficient. Here we used Nile Red, a lipid-soluble fluorescent probe, to establish a novel method to determinate the level of lipids in mi-croalgae rapidly and accurately. We applied the Nile Red method to investigate the dynamic accumulation of lipids in Isochry-sis sp. CCMM5001 under different culture conditions. The results showed that there was a linear correlation between the lipids level and the cellular fluorescence of stained microalgal cells, therefore the former can be accurately indicated by the latter. Low nitrogen concentrations and low temperatures were suitable for accumulating of lipids. The level of lipids was reduced if the illumination intensity was overly high or low. On one hand the optimal conditions for the growth were:N concentration at 1323 µmol/L, illumination intensity at 148.0 µmol/(m2·s), and the temperature at 25℃. On the other hand for the maximal accumulation of the lipids, the optimal values of the parameters above were 441 µmol/L, 92.5 µmol/(m2·s), and 15℃respec-tively. The culture condition was optimized and a two-stage cultivation was carried out to increase both the level and the pro-duction rate of lipids, the former reaching a high concentration of 63.3%and the latter reaching 22 mg/(L·d).
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