Growth and Nutrient Utilization of Green Algae in Batch and Semicontinuous Autotrophic Cultivation Under High CO2 Concentration.
The growth performance of Chlorella protothecoides, Chlorella pyrenoidosa, and Chlorella sp. in autotrophic cultivation with 10% carbon dioxide (CO2) was evaluated. The biomass production of C. protothecoides, along with its carbon, nitrogen (N), and phosphorus (P) utilization, in batch and semicontinuous autotrophic cultivation with 20% CO2 was also determined. Among the three algae species, C. protothecoides obtained the highest biomass yield (1.08 g/L) and P assimilation (99.4%). Compared with the CO2 flow rate and inoculation ratio in batch cultivation, light intensity considerably improved biomass yield, N and P assimilation, and CO2 utilization. In the semicontinuous cultivation of C. protothecoides, a hydraulic retention time (HRT) of 8 days kept the system at a stable running state, thereby demonstrating that an HRT of 8 days was better than an HRT of 5 days. Among the three N/P ratios for C. protothecoides in semicontinuous cultivation with 20% CO2, 2:1 provided the highest biomass productivity (0.19 g/L/day) and CO2 fixation rate (0.37 g/L/day). Therefore, this lower N/P ratio is more suitable than 10:1 and 50:1 for the growth of C. protothecoides with 20% CO2. Compared with the batch cultivation of C. protothecoides, semicontinuous cultivation improved the CO2 fixation rate (by 1.5-2 times) and CO2 utilization efficiency (by 3-6 times) of C. protothecoides.
['Liu|Shan|S|', 'Elvira|Perova|P|', 'Wang|Yongkang|Y|', 'Wang|Wei|W|']
D052818:Autotrophic Processes D018533:Biomass D002245:Carbon Dioxide D000460:Chlorophyta D006863:Hydrogen-Ion Concentration D008027:Light D009584:Nitrogen D010758:Phosphorus
High CO2 concentration Biomass production N/P ratios Microalgae cultivation Photobioreactor