Production of lipid containing high levels of docosahexaenoic acid by cultivation of Aurantiochytrium sp. KRS101 using Jerusalem artichoke extract

Abstract

In the present study, we evaluated extract of Jerusalem artichoke tubers (JAT) as a substrate for the production of lipid containing high levels of docosahexaenoic acid (DHA) by cultivated Aurantiochytrium sp. KRS101, an oleaginous protist. The optimal conditions for cultivation determined using response surface methods were as follows: pH, 5.9; enzyme loading, 282.6; and temperature, 27.7°C. The maximal levels of lipid (16.4 g/L) and productivity (3.6 g/L/d) were obtained during fed-batch fermentation, which achieved a DHA yield of 7.9 g/L (>48% of total fatty acids by weight). Moreover, JAT was more economical, reducing costs of expensive yeast extract as a nitrogen source by about 40%. These results suggest that JAT may be further explored as a low-cost feedstock for lipid production using microalgae strains.