Chemo-enzymatic saccharification and bioethanol fermentation of lipid-extracted residual biomass of the microalga, Dunaliella tertiolecta

► The residual biomass of Dunaliella tertiolecta after lipid extraction was saccharified and used for bioethanol fermentation. ► A pretreatment procedure was not required for enzymatic saccharification of the residual biomass. ► Saccharification yield based on the total amount of carbohydrates was 80.9% (w/w). ► Bioethanol was directly produced with 82% yield from the saccharification solution without additional pretreatment. ► The waste residual biomass generated during microalgal biodiesel production could be used for the production of bioethanol.