Use of magnetic fields and nitrate concentration to optimize the growth and lipid yield of Nannochloropsis oculata

Feng-Jen Chu; Terng-Jou Wan; Tzu-Yi Pai; Hsiao-Wen Lin; Shang-Hao Liu; Chung-Fu Huang

doi:10.1016/j.jenvman.2019.109680

Use of magnetic fields and nitrate concentration to optimize the growth and lipid yield of Nannochloropsis oculata

J Environ Manage. 2020 Jan 1:253:109680. doi: 10.1016/j.jenvman.2019.109680. Epub 2019 Oct 18.

Authors

Feng-Jen Chu¹, Terng-Jou Wan², Tzu-Yi Pai³, Hsiao-Wen Lin⁴, Shang-Hao Liu⁵, Chung-Fu Huang⁶

Affiliations

¹ Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan.
² Department of Safety, Health and Environment Engineering, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan. Electronic address: Wantj@gemail.yuntech.edu.tw.
³ Master Program of Environmental Education and Management, Department of Science Education and Application, National Taichung University of Education, Taichung, 40306, Taiwan.
⁴ Department of Safety, Health and Environment Engineering, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan.
⁵ Department of Chemical Engineering, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
⁶ School of Environmental and Chemical Engineering, Zhaoqing University, Zhaoqing, 526061, Guangdong, China.

PMID: 31634748
DOI: 10.1016/j.jenvman.2019.109680

Abstract

Microalgae produce increased lipid content accompanied by a significant decrease in cell density with decreasing nitrate concentration. Magnetic fields (MF) have been reported as a factor that could accelerate metabolism and growth in microalgae culture. Thus, this study aimed to optimize the influence of MF and nitrate concentration (sodium nitrate, N) on the growth and lipid productivity of Nannochloropsis oculata. A single-factor experiment integrated with response surface methodology (RSM) via central composite design (CCD) was performed. The results showed that the maximum specific growth rate (0.24 d^-1) and maximum lipid productivity (38 mg L^-1 d^-1) obtained in this study were higher than those of the control culture (by 166% and 103%, respectively). This study also found that the two-way interaction term MF × N had a significant effect on cell growth but not on lipid production. It was concluded that to design appropriate MF for enhanced lipid productivity due to cell growth, further research must focus on developing an understanding of the relationship between the bioeffects of the magnetic field and the proteomic changes involved in lipid accumulation strategies. This approach would enable the design of conditions to obtain inexpensive high-value products from N. oculata.

Keywords: Lipid productivity; Magnetic fields; Nannochloropsis oculata; Response surface methodology; Sodium nitrate.

MeSH terms

Biomass
Lipids
Magnetic Fields
Microalgae*
Proteomics
Stramenopiles*

Substances

Lipids