Cultivation of a thermo-tolerant microalga in an outdoor photobioreactor: Influences of CO2 and nitrogen sources on the accelerated growth

► Acidic acetonitrile for intracellular tryptophan extraction was adopted. ► Changes of transport systems for L-tryptophan leaded to a higher yield of L-tryptophan by metabolic flux redistribution. ► The strengthen of exporter was more effective than other modifications in the fermentation of L-tryptophan.