Lipids extraction from the green alga Ankistrodesmus falcatus using different methods

Abstract

Ankistrodesmus falcatus is a single-cell green alga with extremely tough cell walls; that could be difficult to disrupt in order to extract lipids. In this work various methods, including very fine grind, autoclaving, microwaves, sonication and osmotic shock at 10 % NaCl solution, using solvents systems, hexane, hexane:diethyl ether (1:1 v/v), hexane:isopropanol (1:1 v/v) and chloroform:methanol (1:1 v/v) were tested to identify the most effective cell disruption method. The highest lipid and fatty acids productivity were obtained by osmotic shock method using chloroform:methanol (1:1 v/v) 11.93 % of dry weight and 75.26 % of lipid productivity, respectively. Thus, among the tested methods and solvent systems, the osmotic shock with chloroform:methanol (1:1 v/v) was the most simple, easy, and effective method for lipid extraction from A. falcatus. The analysis of crude lipids by GC–MS showed that the dominant types of fatty acids were palmitic acid (hexadecanoic acid) (48.74, 57.82, 52.22, 20.91 and 47.97 %), stearic acid (octadecanoic acid) (5.75, 5.68, 4.93, 0.88 and 1.74 %) and myristic acid (tetradecanoic acid) (2.87, 2.37, 1.29, 0 and 3.16 %) with very fine grind, osmotic shock, autoclaving, sonication and microwaves using chloroform:methanol (1:1 v/v), respectively.