Enhancing astaxanthin production from Chromochloris zofingiensis via blue light and exogenous inducers in plate photobioreactors.

This study investigates the photoinduction techniques for the maximization of astaxanthin production in Chromochloris zofingiensis following heterotrophic growth. Leveraging blue light, this study enhanced carbon allocation by suppressing the tricarboxylic acid cycle and activating the methylerythritol phosphate and pentose phosphate pathways to facilitate astaxanthin accumulation. Under blue light, an astaxanthin content of 5.14 ± 0.40 mg g was achieved in flasks for 5 day, while in larger 3-L plate photobioreactors, the content was 5.76 ± 0.55 mg g in only 3 days by the increased light intensity and diluted biomass concentration. Moreover, higher astaxanthin level of 6.26 ± 0.53 mg g in peaks at 36 h was also realized by exogenous inducer (gibberellin A, 2 mg L and HO, 5 mL L) with productivity of 39 mg L d. These outcomes are promising for scaling up sustainable astaxanthin production with useful commercial applications in the pharmaceuticals, cosmetics, and nutraceutical industries.