Metabolic profiling identified phosphatidylcholin as potential biomarker in boosting lipid accumulation in multiple microalgae

Abstract

The scenario of this work was to excavate co-owned metabolic biomarkers responsible for lipid accumulation by freshwater Chlorella protothecoides (CP), polar Coccomyxa subllipsoidea (CS), and marine Nannochloropsis oculata (NO). The dose-time effects between lipid content and urea concentration showed that CP, CS, and NO reached optimal lipid content of 57%, 63.84%, and 59.95% with 0.5, 1.0, and 0 g/L urea induction for 24 h, 12 h, and 24 h. Metabolomics revealed that 16 compounds including phosphatidylcholin (PC) were excavated as co-owned metabolites in optimal lipidic CP, CS, and NO. In light of contributions in influencing cluster formation of S score plot that 8 of 16 compounds were identified as potential metabolic biomarkers served for lipid accumulation in microalgae. Preliminary verifications demonstrated that PC experienced neomycin biosynthesis inhibition allowed 138.74%, 145.24%, 100%, and 168% increments in lipid contents of CP, CS, NO, and newly-employed Chlamydomonas reinhardtii (CR). Another indisputable case was that lipid productivities were 2.09-, 2.20-, 1.71-, and 2.6-fold more than that of controls and C16-C18 fatty acid proportions (>76%) in CP, CS, NO, and CR were also recommendable for biodiesel-making. These co-owned metabolic biomarkers might be universally-available targets in boosting lipid accumulation and would offer valuable clues in delving into regulatory mechanisms of lipid biosynthesis in microalgae.