微藻细胞油脂含量的快速检测方法

以斜生栅藻(Scenedesmus obliquus JNU20)为实验材料,采用尼罗红(NR)荧光光谱法和傅里叶变换红外光谱法(FTIR)测定该藻细胞中的油脂含量。研究结果表明NR的最佳染色条件为:染色前微波处理40 s,二甲基亚砜体积分数1%, NR最终质量浓度1.5 μg/ml,染色时间5 min,染色温度40℃。比较了NR荧光光谱法、FTIR与传统重量法测定的该藻在不同时相的油脂积累情况,利用激光共聚焦显微镜观察了细胞中油体形成的动态过程。实验结果表明NR荧光光谱法、FTIR与传统重量法测定的结果显著相关(R²=0.9258, R²=0.9844),但NR荧光光谱法和FTIR更简便快速,研究结果为规模化筛选高含油量藻株及跟踪产油微藻油脂积累过程奠定了基础。

Rapid Estimation of Lipids in Microalgae Cells

The Nile red(NR)fluorescence and Fourier transform infrared micro-spectroscopy(FTIR)was used to determine lipid content over time in freshwater microalgae Scenedesmus obliquus JNU20.The optimum staining conditions for S.obliquus JNU20 were as follows:pretreated 40s with microwave before staining,the volume fraction of dimethylsulfoxide was 1%,the final concentration of Nile red dye was 1.5 μg/ml and incubation 5 min at 40℃.At the different growth phases,fluorescence spectrometer and FTIR spectrometer and gravimetric methods were used to determine lipid content in S.obliquus JNU20 grown in limiting concentration of nitrogen(0.5 g/L NaNO3),the dynamic process of lipid body formation was also observed by laser scanning confocal microscopy,the results of spectrofluorimetric and FTIR spectrometric methods were very strong correlated with the results determined by gravimetric method(R2=0.925 8,R2=0.984 4),respectively.This strong correlations thus validate that the spectrofluorimetric and FTIR spectrometric methods described provide rapid,easy manipulated and reliable methods for quantification of lipids in microalgae.It was the basis of wide-scale screening of oleaginous algal strains and tracking the process of lipid accumulation in oleaginous algae.