Sophorolipid biosurfactants application as novel approach to lipid extraction from Chlorella cultures

Authors: Msanne, Joseph; Ashby, Richard; Harron, Andrew

Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Algal lipids have diverse applications in industries such as biofuels, nutraceuticals, pharmaceuticals, and cosmetics. They represent a promising alternative to traditional plant oils and animal fats. However, the high costs of extraction and recovery still pose significant challenges. These extraction processes include use of toxic and environmentally hazardous solvents including methanol and chloroform. In this work, we have tested using small amounts of sophorolipids, a biologically derived detergent, as an additive to rupture algal cells and allow for extraction of the algal oils using ethyl acetate, a more environmentally benign solvent. The results showed that this method provided comparable oil extraction yields to the traditional method. This information will be valuable to US producers cultivating algae or processing algae for use in bioproducts.

Technical Abstract: Algal lipids and high-value biomaterials have diverse applications in industries such as biofuels, nutraceuticals, pharmaceuticals, and cosmetics. They represent a promising alternative to traditional plant oils and animal fats. However, the high costs of extraction and recovery still pose significant challenges. In the present study, a novel method involving treatment of Chlorella sorokiniana cultures with sophorolipid (SL) biosurfactants was initially developed to facilitate the release of lipids prior to extraction with ethyl acetate (EA), a low toxicity solvent with reduced environmental impacts. Microscopy analyses confirmed the proficiency of sophorolipids in enhanced cell disruption and accessibility to intracellular biomaterials. Lipid extraction efficiency was evaluated and compared with the traditional Bligh and Dyer (B&D) method, which uses hazardous solvent combinations. Under room conditions, EA extraction of cultures subject to 2 days nitrogen deprivation and 12 h incubation with 1 mg/mL SL, yielded 85% total lipids compared to the B&D method. Under these conditions, the lipid profile consisted of 65% of both saturated and monounsaturated fatty acids confirming the extract suitability as potential biodiesel feedstock. The procedure allowing recovery of high lipid yields while considerably reducing the use of organic solvents, offers high potential for industrial-scale implementation and large-scale commercialization of microalgae-based products.