Comprehensive analysis of metabolic alterations in Schizochytrium sp. strains with different DHA content.

Along with the daily growth of the market requirements for docosahexaenoic acid (DHA) algae oil, a large DHA ingredients are needed to ensure worldwide supply. Undoubtedly a high-productive strain would be the prerequisite for high quality and yield. A comprehensive understanding of the processes of DHA synthesis from glycolysis to the lipid accumulation would be benefit to achieve the final optimization of DHA production. In this study, we comprehensively characterized the metabolic profiles of a Schizochytrium sp. strain, which has higher DHA content and different biomass amino acid composition compared with the wild type to explore the affected pathways and underlying mechanism. Combined with the multivariate statistical analysis, twenty-two differential metabolites were screened as relevant to the discrepancy between two strains. The results showed relatively downregulated glycolysis and saturated fatty acids (SFA) synthesis, and upregulated TCA cycle, amino acids and polyunsaturated fatty acids (PUFA) synthesis in DHA high yield strain. The current study provide a terminal picture of gene regulation from downstream metabolism and demonstrate the advantage of metabolomics in characterizing metabolic status which in turn could provide effective information for the metabolic engineering.