DHA production by Schizochytrium limacinum SR-21 using crude glycerol as carbon source

Abstract

This study investigates the potential of low-cost substrates (crude glycerol) usage as carbon source for obtaining docosahexaenoic acid (DHA), through fermentation of the Schizochytrium limacinum SR-21 microalga. The fermentations were conducted on flask and bioreactor scale. To quantify the amount of DHA obtained, the amount of biomass and lipid production were monitored and simultaneously running fermentative processes on two substrates were carried out. In both processes (flask and bioreactor) the highest amount of dry biomass (DB) was obtained by using glucose as carbon source (6.9 g L -1 in flask and 10.65 g L -1 in bioreactor). Although the amount of DB was higher on blank substrate, the level of DHA from total lipids content was higher (27.69 % in flask and 36.06% in bioreactor) in the biomass obtained on glycerol as primal carbon source. The highest quantity of DHA was obtained by using crude glycerol as carbon source for the microalgae when carrying out the process on bioreactor scale, which allowed us to control the pH on a set value of 7.5