Optimization of culture methods and chemical properties of mutant Dunaliella sp. biomass under different scales and culture regimes

Abstract

The green unicellular flagellate Dunaliella sp. (Chlorophyceae) are motile, rod to oval shaped (9&#8722 11 &micro m) and halophilic. Dunariella sp. is the richest natural source of the carotenoids which are highly accumulated under hypersaline condition. In member of the carotenoids, zeaxanthin is a golden pigment and has an important part in natural products industries using its vigorous antioxidant activities. In this study, Dunaliella sp. reported by Kim et al. (2017) was cultured in the f medium with PBRs (5 L and 300 L) and 5 ton-scaled open raceway pond in KIOST Jeju Center to identify the scale-up stability of growth and chemical cell components under different regimes. In different pH conditions, Dunariella sp. was significantly higher grown in 10.5 than below levels (p<0.01). In different salinity conditions, Dunariella sp. was significantly higher grown in 45 and 50 psu than other levels. In 5 L scaled-PBR cultured from February to March 2017, maximum biomass reached up to 0.62±0.04 g/L in 18 days after inoculation. In 300 L scaled-PBR culture during the period from March to May 2017, maximum biomass in each batch reached up to 0.43±0.03 g/L (Lot#1), 0.39±0.01 g/L (Lot#2), 0.44±0.01 g/L (Lot#3), and 0.53±0.02 g/L (Lot #4) in 20, 10, 10 and 4 days after inoculation. However, the medium was generally contaminated by zooplankton (e.g. ciliate) in 10&#8210 14 days after inoculation. For avoiding contaminatine condition. In member of the carotenoids, zeaxanthin is a golden pigment and has an important part in natural products industries using its vigorous antioxidant activities. In this study, Dunaliella sp. reported by Kim et al. (2017) was cultured in the f medium with PBRs (5 L and 300 L) and 5 ton-scaled open raceway pond in KIOST Jeju Center to identify the scale-up stability of growth and chemical cell components under different regimes. In different pH conditions, Dunariella sp. was significantly higher grown in 10.5 than below levels (p<0.01). In different salinity conditions, Dunariella sp. was significantly higher grown in 45 and 50 psu than other levels. In 5 L scaled-PBR cultured from February to March 2017, maximum biomass reached up to 0.62±0.04 g/L in 18 days after inoculation. In 300 L scaled-PBR culture during the period from March to May 2017, maximum biomass in each batch reached up to 0.43±0.03 g/L (Lot#1), 0.39±0.01 g/L (Lot#2), 0.44±0.01 g/L (Lot#3), and 0.53±0.02 g/L (Lot #4) in 20, 10, 10 and 4 days after inoculation. However, the medium was generally contaminated by zooplankton (e.g. ciliate) in 10&#8210 14 days after inoculation. For avoiding contaminat