A novel drying film culture method applying a natural phenomenon: Increased carotenoid production by<i> Haematococcus</i> sp

Abstract

Low productivity and high cost remain major bottlenecks for the large-scale production of Haematococcus sp. This study explored biomass production and carotenoid accumulation in Haematococcus sp. (KCTC 12348BP) using drying film culture. The broth-cultured strain (3.2 x 106 cells/mL, 0.83 +/- 0.02 mg/mL for a 21 d culture) was cultured under various conditions (different inoculum volumes and mist feeding intervals) in waterless agar plates at 28 +/- 0.5 degrees C, under fluorescent light (12 h light-dark cycle) for 1 month. The maximum biomass obtained was 17.60 +/- 0.72 g/m2, while the maximum astaxanthin concentration was 8.23 +/- 1.13 mg/g in the culture using 1 mL inoculum and 3 d feeding interval. Drought stress in drying film culture effectively induced the accumulation of carotenoids from beta-carotene, facilitating the production of canthaxanthin via the astaxanthin biosynthesis pathway. This cost-effective culture system can increase the biomass and carotenoid pigment production in Haematococcus sp.