A green and efficient technology for sequential extraction of lipid and paramylon from Euglena gracilis

Euglena gracilis is rich in nutrients and high-value metabolites. However, at present, most studies only extract the paramylon of E. gracilis, which is a waste of resources. In this study, a method of sequential extraction of lipid and paramylon from E. gracilis was studied, and the extraction conditions were optimized. Firstly, by optimizing the solid-liquid ratio, extraction time, extraction temperature and volume ratio of n-hexane to ethanol, the lipid extraction efficacy was increased from 73.0 % to 96.0 %. Next, paramylon was extracted from the E. gracilis residue. After optimizing the enzyme type, enzyme concentration, ratio of material to liquid and enzymolysis time, the protein removal rate was 91.3 %, the yield of paramylon was 58.3 % and the purity reached 89.3 %. Compared with the traditional method, this sequential extraction method was greener and more effective for the extraction of paramylon and lipids from E. gracilis, which can promote the comprehensive utilization of algae resources.