No abstract

Nannochloropsis salina (N. salina) has recently received growing interests as a sustainable source of high‐value bioproducts. As the illumination condition could be manipulated to affect the microalgae activities in indoor cultivation, in this study, kinetic models were developed to describe the growth and bioproduct formation in N. salina under different illumination conditions. Being continuously exposed to white (380–760 nm), blue (430 nm), red (680 nm), and mixed blue/red light, the growth of N. salina was assessed over the course of 12 days incubation and the evolving cell densities, lipid, and carbohydrate concentrations were recorded. Kinetic models were then used to fit the experimental results and describe microalgae behaviors with respect to illumination conditions. The highest growth rates were recorded when the microalgae were exposed to the blue/red light, leading to 0.8 g/L standing dry biomass. Also, although lipid and carbohydrate productions were stimulated under other illumination conditions, the advanced biomass production achieved by blue/red light resulted in the highest lipid and carbohydrate productions. As confirmed by the kinetic models, the results obtained in this study revealed that the light absorbed by the photosynthetic pigments of N. salina could be manipulated to not only control the microalgae growth, but also its biological activities, including carbohydrate and lipid productions. Therefore, a two‐stage process would be recommended for lipid and carbohydrate production by N. salina.