Repetitive non-destructive extraction of lipids from Chlorella vulgaris grown under stress conditions

The aim of this study was the investigation of non-destructive lipid extraction from Chlorella vulgaris grown under stress conditions of nutrient limitation and salinity. To select a suitable solvent for extraction, the performances of decane, dodecane and hexadecane were tested based on their effect on lipid extraction and cell viability. The results showed that dodecane was the most suitable solvent for the extraction process. The concentration of extracted lipids from stressed cells was 2762.52 ± 11.38 mg L−1, i.e. a value 1.75 times higher than that obtained from unstressed cells. Long-term extraction was also evaluated with continuous dodecane recirculation during five-stage extraction and a recovery time of 24 h between the extraction steps, which yielded after the fifth extraction stage a total lipid amount as high as 9811.56 mg L−1. These results showed that non-destructive lipid recovery can be effectively performed by applying stress conditions and in repetitive extractions.