Photoautotrophic cultivating options of freshwater green microalgal Chlorococcum humicola for biomass and carotenoid production

ABSTRACTPhotoautotrophic cultivation of Chlorococcum humicola was performed in batch and continuous modes in different cultivating system arrangements to compare biomass and carotenoids’ concentration and their productivities. Batch result from stirred tank and airlift photobioreactors indicated the positive effect of increasing light intensity on growth and carotenoid production, whereas the finding from continuous cultivation indicated that carotenoid enhancement preferred high light intensity and nitrogen-deficient environment. The highest biomass (1.31 ± 0.04 g L−1) and carotenoid (4.59 ± 0.06 mg L−1) concentration as well as the highest productivities, 0.46 g L−1 d−1 for biomass and 1.61 mg L−1 d−1 for carotenoids, were obtained when maintaining high light intensity of 10 klx, BG-11 medium and 2% (v/v) CO2 simultaneously, while the highest carotenoid content (4.84 mg g−1) was associated with high light intensity and nitrogen-deficient environment, which was induced by feed-modified BG-11 growth mediu...