Enhancing lipid extraction from green microalgae Chlorella sp. using a deep eutectic solvent pretreatment

In recent years, many researchers have focused on microalgae as a potential source of lipids for various purposes. To improve the lipid yield, different biomass pretreatments have been investigated. The aim of this work was to determine the effect of an ultrasound and deep eutectic solvent (DES) pretreatment on lipid yield from green microalgae Chlorella sp. The chosen DESs were choline chloride:urea (ChCl:U), choline chloride:glycerol (ChCl:G) and choline chloride:acetic acid (ChCl:Aa), all in the mole ratio of 1:2. Lipids were extracted from the pretreated and untreated biomasses by Bligh and Dyer?s method. The results showed that the lipid yields for the untreated and ultrasound-pretreated biomass were 39 and 48%, respectively. The pretreatments with ChCl:U, ChCl:G and ChCl:Aa resulted in lipid yields of 51, 46 and 40%, respectively. Therefore, the use of efficient and environmentally friendly DESs for the microalgae biomass pretreatment resulted in a higher lipid yield.