title: Control of CO₂ input conditions during outdoor culture of Chlorella vulgaris in bubble column photobioreactors.
abstract: A study on the optimization of CO2 usage during outdoor microalgae cultivation in order to further maximize the CO2 to biomass conversion efficiency is presented. A constant supply of CO2 was found to be non-essential for culturing microalgae outdoors in 80 L (8 L×10 sets) bubble columns. Among the different CO2 input conditions that were studied, 2% CO2 with intermittent supply and 2%+4% CO2 alternation did not affect the algal growth as compared to having a constant supply of 2% CO2. However, during both input conditions, the CO2 to biomass conversion efficiency was doubled while the amount of CO2 used was reduced by 50%. The algal biomass obtained was found to have a higher carbohydrate yield but a lower protein yield as compared to previously published studies. The findings from this study could be applied for large-scale microalgae production so as to minimize cultivation and energy costs.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
authors: Zhi
authors: Z
authors: Guo
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
authors: Wei Boon Alfred
authors: WBA
authors: Phooi
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
authors: Zi Jian
authors: ZJ
authors: Lim
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore. Electronic address: chetyw@nus.edu.sg.
authors: Yen Wah
authors: YW
authors: Tong
mesh_terms: D000704:Analysis of Variance; D018533:Biomass; D002241:Carbohydrates / Q000096:biosynthesis; D002245:Carbon Dioxide / Q000378:metabolism*; D048408:Chlorella vulgaris / Q000254:growth & development*; D046508:Culture Techniques / Q000379:methods*; D005227:Fatty Acids / Q000096:biosynthesis; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000378:metabolism; D058433:Photobioreactors / Q000382:microbiology*
chemical_list: D002241:Carbohydrates; D005227:Fatty Acids; D002245:Carbon Dioxide; D010100:Oxygen
keywords: Bubble column; CO(2) input condition; Chlorella vulgaris; Outdoor microalgae cultivation; Photobioreactors