title: Engineering strategies for enhancing the production of eicosapentaenoic acid (EPA) from an isolated microalga Nannochloropsis oceanica CY2.
abstract: Microalgae have emerged as promising resources for highly unsaturated fatty acids. In this study, an indigenous microalga identified as Nannochloropsis oceanica CY2 was grown photoautotrophically to produce eicosapentaenoic acid (EPA; 20:5, n-3). Specific engineering strategies were employed to stimulate EPA accumulation in the microalgal cells. The results show that BG-11 was the most effective medium to grow N. oceanica CY2, giving an EPA content and biomass concentration of 2.38% (per dry cell weight) and 1.53 g/l. The EPA content nearly doubled when using the optimal nitrogen source (NaNO3) at a concentration of 1.50 g/l. The illumination system also markedly affected the EPA content for the photoautotrophic microalga. When the microalgal culture was illuminated with a red LED, an impressively high EPA content of 5.5% was obtained. Finally, using semi-batch cultures operations with LED-blue illumination, the EPA content of N. oceanica CY2 was stably maintained at 5.0%.
authors.affiliation: University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan. Electronic address: ccy.ncku@gmail.com.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Hsiao-Chen
authors.initials: HC
authors.lastname: Huang
authors.affiliation: Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan; Department of Life Science, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Chieh-Chen
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Mathematics and Physics, Air Force Academy, Gangshan, Kaohsiung 820, Taiwan.
authors.forename: Wen-Lung
authors.initials: WL
authors.lastname: Lee
authors.affiliation: University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan; Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan. Electronic address: changjs@mail.ncku.edu.tw.
authors.forename: Jo-Shu
authors.initials: JS
authors.lastname: Chang
mesh_terms: D018533:Biomass; D019149:Bioreactors; D015118:Eicosapentaenoic Acid / Q000096:biosynthesis*; D058086:Microalgae / Q000378:metabolism*
chemical_list: D015118:Eicosapentaenoic Acid
keywords: Eicosapentaenoic acid (EPA); LED; Microalgae; Nannochloropsis oceanic; Photobioreactor