Use of organic waste from the brewery industry for high-density cultivation of the docosahexaenoic acid-rich microalga, Aurantiochytrium sp. KRS101

► Spent yeast was used to cultivate DHA-rich microalga, Aurantiochytrium sp. KRS101. ► A significant biomass was obtained using only spent yeast as a sole substrate. ► To make complete use of nutrients, KRS101 was cultivated in a stepwise manner. ► Use of spent yeast can substantially reduce the production cost of microalga DHA.