Quantitative detection on metabolites of Haematococcus pluvialis by terahertz spectroscopy

Abstract

Stressed Haematococcus Pluvialis cells would accumulate astaxanthin with the changes of lipid, pigment, and starch, which recently has been widely studied. Real-time dynamic monitoring of these components will have important guiding significance for screening high-yield and high-quality strains in the industry. Terahertz spectroscopy is not only suitable for measuring large flux samples, but also widely used for quantitative analysis of multicomponent mixtures. To investigate the potential of using terahertz spectroscopy to monitor and quantify metabolites in the algae, terahertz spectrum of Haematococcus Pluvialis under nitrogen starvation were captured and examined against those standard reagents of β-carotene, astaxanthin, and starch. The correlation between intensities of the characteristic peaks and the metabolite contents which were quantified by chemical analysis was established, and the results showed the correlation coefficient were higher than 0.92, indicating a relatively accurate performance to predict the metabolites concentration. Furthermore, to identify meaningful spectra range for quantification, the partial least squares combined with intensities of the interval characteristic peaks were established, where it demonstrated an accurate model with high prediction correlation coefficients (greater than0.98), low root-mean-square error of prediction (RMSEP), and high residual predictive deviation. The results approve the feasibility of using terahertz spectroscopy for synchronous detection on metabolites concentration in the microalgae production process.