Tetraselmis suecica LIPID EXTRACTION: ULTRASONIC AND SOLVENT AIDED PROCESS

The growth kinetics of Tetraselmis suecica cultured in nitrogen-limited media was evaluated; this allowed establishing. the microbiological basic kinetic parameters of cultures to lipid and residual biomass production. This paper proposes a methodology to modify the traditional oil solvent-extraction by using high efficient ultrasound; this method includes separation process of chlorophyll from oil phase. Mass spectroscopy coupled to gas chromatography (MS-GC) was used to determine the fatty acid profile (PAP) from the final composition of the fatty acid methyl esters (FAME) obtained from oil sonotransesterification. FAP was not altered by the effect of nitrogen stress, and it was observed that oil composition of Tetraselmis suecica was: palmitic acid, 28.86; stearic acid, 28.33; oleic acid, 16.79; linoleic acid, 11.71, and linolenic acid, 14.31 wt.%. Finally, the response surface methodology (RSM) was used to find the best operational conditions of the extraction process in terms of the quantity of solvent used (X-1), sonication time (X-2) and ultrasonic power (X-3), with pulses and without pulses of sonication. The best extraction process conditions with continuous sonication occurred at X-1 = 5 mL g(-1), X-2 = 6 h and X-3 = 160W, ensuring an extraction efficiency of 94.98%.