Optimal extraction conditions for increasing microalgal lipid yield based on an accelerated solvent extraction method

Biofuel,as an alternative fuel,is recently attracting increasing attention.Many studies have been performed on the cultivation of various microalgae and extraction of algal lipids for further biofuel production.To obtain higher algal lipid yield,it is crucial to adopt appropriate methods and conditions for lipid extraction.Traditional methods of microalgal lipid extraction are difficult and consume large amounts of toxic organic solvents along with a long operation time.This study investigated and determined optimal treatment conditions including extraction solvents(hexane,chloroform,petroleum ether,ethanol,and acetone),temperature(75~175℃),time(4~20 min),and cycle(1~5) through the designation of an orthogonal experimentation with four factors and five levels in order to achieve rapid and efficient lipid extraction from microalgae using an accelerated solvent extraction method(ASE).The current study determined that all extraction factors(excluding cycle) significantly influenced microalgal lipid yield(p0.035),which ranged between 2.98%~21.36%.alga depending on different extraction conditions.The highest lipid extraction values reached 19.21%~21.36%.alga under optimal treatments with solvents such as ethanol or acetone,175℃,16 min,3 cycles and increased lipid extraction by 39.08%~47.09% in comparison with the conventional Soxhlet method.Therefore,a rapid and effective lipid yield maximum could be obtained using optimal ASE treatment conditions for microalgal lipid extraction.