title: Development of a stepwise aeration control strategy for efficient docosahexaenoic acid production by Schizochytrium sp.
abstract: The effect of aeration on the performance of docosahexaenoic acid (DHA) production by Schizochytrium sp. was investigated in a 1,500-L bioreactor using fed-batch fermentation. Six parameters, including specific growth rate, specific glucose consumption rate, specific lipid accumulation rate, cell yield coefficient, lipid yield coefficient, and DHA yield coefficient, were used to understand the relationship between aeration and the fermentation characteristics. Based on the information obtained from the parameters, a stepwise aeration control strategy was proposed. The aeration rate was controlled at 0.4 volume of air per volume of liquid per minute (vvm) for the first 24 h, then shifted to 0.6 vvm until 96 h, and then switched back to 0.4 vvm until the end of the fermentation. High cell density (71 g/L), high lipid content (35.75 g/L), and high DHA percentage (48.95%) were achieved by using this strategy, and DHA productivity reached 119 mg/L h, which was 11.21% over the best results obtained by constant aeration rate.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing, People's Republic of China.
authors.forename: Lu-Jing
authors.initials: LJ
authors.lastname: Ren
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Ji
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Liang
authors.initials: L
authors.lastname: Qu
authors.forename: Yun
authors.initials: Y
authors.lastname: Feng
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Tong
authors.forename: Ping-Kai
authors.initials: PK
authors.lastname: Ouyang
mesh_terms: D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D056890:Eukaryota / Q000254:growth & development* / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D050356:Lipid Metabolism; D010100:Oxygen / Q000378:metabolism
chemical_list: D003470:Culture Media; D004281:Docosahexaenoic Acids; D005947:Glucose; D010100:Oxygen