Unveiling Tetraselmis subcordiformis lipidome dynamics during large-scale cultivation in open raceway pond

A local microalgal strain of Tetraselmis subcordiformis was cultivated at large-scale using open raceway pond. The temporal influence on the growth and lipidomic profile of the strain was investigated using optic density (OD) measurement and ultra-high pressure liquid chromatography. Results showed that triglycerides represented 57% of the total lipids on day 11 (exponential phase) and stayed consistently high until stationary phase, without affecting the biomass quantity. Moreover, a high expression of monounsaturated fatty acids and polyunsaturated fatty acids such as ω-3 eicosapentaenoic acid (20:5), docosahexaenoic acid (22:6), palmitic (16:0) and palmitoleic acid (16:1) was observed by stationary phase. Carotenoid analysis also revealed the increase in lutein (65.2%) and β-carotene (71.4%) from day 6 to day 15. Our study showed that T. subcordiformis contained the highest amounts of valuable lipids, fatty acids and pigments in the stationary phase, which started on day 15 of culture.