High-density fed-batch culture of a thermotolerant microalga Chlorella sorokiniana for biofuel production

► Reveal the relationship between nitrogen consumption and pH change. ► Obtain a high growth rate of 0.133 h−1 through optimization. ► Achieve high biomass and lipid concentrations of 103.8 g L−1 and 40.2 g L−1. ► Perform lipid class analysis for the microalga Chlorella sorokiniana. ► Evaluate biodiesel characteristics based on the fatty acids compositions.