小球藻生长过程脂肪含量动态变化快速无损检测方法研究

微藻-生物柴油转化生产要求产油微藻细胞内大量积累脂肪,而藻类脂肪的积累受外界环境影响较大,因此,微藻生长过程中对藻体脂肪变化进行快速检测和分析有着非常重要的意义。以小球藻(Chlorella sp.)为研究对象,利用可见/近红外光谱技术和高光谱成像技术对不同光源培养条件下微藻生长过程脂肪动态变化和脂肪含量分布可视化分析进行了研究。研究结果表明,虽然利用两种技术获取的小球藻透射光谱和反射光谱有差异,利用连续投影算法进行特征波长也不完全相同,但基于两种技术获得的对于脂肪含量的特征波段光谱建立的小球藻脂肪含量多元线性回归模型的预测结果接近,分别为r_(pre)=0.940,RMSEP=0.003 56和r_(pre)=0.932,RMSEP=0.004 23。研究中小球藻接种初期至生长指数期初期藻体内脂肪含量相对平稳,积累增加发生在生长对数期的末期,而在生长平稳期时的小球藻藻液中,脂肪含量较高的藻体呈现出聚集生长的状态。小球藻生长过程中生命信息快速无损检测方法的实现为微藻实际生产培养和收获策略的制定提供了理论依据和技术手段。

Study on the Nondestructive Detection Methods for Dynamica Change of Lipid Content in Chlorella sp

Microalgae based biodiesel production requires a large amount of lipid accumulation in the cells,and the accumulation is greatly influenced by the environment.Therefore,it is necessary to find fast and non-destructive methods for lipid change de-tection.In this paper,Chlorellasp.was adopted as the objective,which was cultured under different light condition consisted of red and blue lights with different proportion.We applied the visible near-infrared spectroscopy (Vis/NIRs)technique to detect the dynamic change of lipid during the microalgae growth processes and utilized hyperspectral imaging technology for visualiza-tion of lipid distribution in the suspension.The transmittance and reflectance spectra of microalgae were acquired with Vis/NIRs and hyper-spectroscopy,respectively.In the comparison of the transmittance and reflectance spectra,they showed some differ-ent characteristics.Meanwhile it also varied in terms of the number and the area of feature wavelengths obtained by successive proj ections algorithm (SPA)based on the different spectra.But the established multiple linear regression (MLR)model for lipid content prediction had similar results with rpre of 0.940,RMSEP of 0.003 56 and rpre of 0.932,RMSEP of 0.004 23,respec-tively.Based on the predictive model,we obtained the spectra and analyzed the lipid dynamic change in microalgae in one life cy-cle.In the life cycle,the lipid content in Chlorella sp.was relatively stable from the beginning of inoculation to exponential phase,the increase and accumulation of lipid phenomenon occurred in the late exponential phase.Combined with the MLR model and the hypersepctral images,we studied the visualization result of microalgae suspension in the steady phase.The stimulated images showed that the microalgae with higher lipid content appeared gathering.This study compared the difference and the fea-sibility of the Vis/NIRs and hyperspectral imaging technique in lipid content detection applied in microalgae growing microalgae. The results are meaningful for the fast and non-destructive detection of the growth information of microalgae.It has boththeoret-ical and practical significance for developing microalgal culture and harvest strategy in practice.