Two-level factorial analysis of the effect of fructose on DHA biosynthetic capacity of Aurantiochytrium sp. SW1

Abstract

Thraustochytrids are getting increasingly popular due to their high potential role as alternative producers of the high-valued ω-3 polyunsaturated fatty acids (PUFA), docosahexaenoic acid (DHA). While most thraustochytrids prefer glucose as the major carbon source, few strains have been reported to prefer fructose. One such strain is Aurantiochytrium sp. SW1. In this study, the effect of fructose on DHA accumulation by SW1 was investigated using a two-level full factorial design. Besides, biomass, lipid and DHA accumulation profiles of SW1 cultivated in fructose and glucose media were compared. Results revealed that fructose has a very significant positive effect on the volumetric DHA content. Meanwhile, its involvement in affecting DHA biosynthetic capacity, though significant, is not very profound. It was also found that when cultivated in fructose medium, SW1 had a less steep log phase compared to that of glucose medium. However, after 48h of cultivation, biomass and lipid accumulation in fructose medium outweighed the other. Volumetric DHA content in fructose medium at 96h was 11% higher than that of glucose medium. Overall, fructose was found to be a more suitable substrate for biomass, lipid and DHA accumulation in SW1 compared to the conventional source, glucose.

Harvesting Aurantiochytrium sp. SW1 via Flocculation Using Chitosan: Effects of Flocculation Parameters on Flocculation Efficiency and Zeta Potential

“…The production of DHA from thraustochytrids commonly involves upstream and downstream processing. Upstream processing such as strain development, as well as the development of fermentation processes that induce the cells to produce high biomass and lipid production, has been extensively studied and developed to date [9][10][11][12]. However, less focus has been placed on the development of downstream processing, especially the harvesting and dewatering of the lipid biomass, even though it is one of the major hurdles in lipids and DHA production associated with these microorganisms.…”