title: The characteristics of TAG and EPA accumulation in Nannochloropsis oceanica IMET1 under different nitrogen supply regimes.
abstract: The strategy of nitrogen limitation has been widely applied to enhance lipid production in microalgae. The changes of cellular composition, and the characteristics of triacylglycerol (TAG) and eicosapentaenoic acid (EPA) accumulation in Nannochloropsis oceanica IMET1 were investigated. The results revealed that after nitrogen limitation TAG rather than carbohydrate was the dominant carbon sink in N. oceanica IMET1. Different nitrogen supplementation strategies were applied in order to achieve high TAG and EPA productivity, respectively. Limited nitrogen was supplied to improve TAG production, and a maximum productivity of 29.44 mg L(-1) d(-1) was obtained, which was a 6.74-fold increase compared to nitrogen-depleted cultivation. The highest EPA productivity of 7.66 mg L(-1) d(-1) was achieved under nitrogen-replete cultivation, which is different from the condition for TAG maximum productivity because the EPA is in glycolipids and phospholipids mainly. The fatty acid composition analysis identified the source of acyl group in TAG accumulation.
authors.affiliation: Marine Bioproducts Engineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 16023, China; School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Marine Bioproducts Engineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 16023, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Marine Bioproducts Engineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 16023, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Marine Bioproducts Engineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 16023, China.
authors.forename: Xupeng
authors.initials: X
authors.lastname: Cao
authors.affiliation: Marine Bioproducts Engineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 16023, China. Electronic address: xuesong@dicp.ac.cn.
authors.forename: Song
authors.initials: S
authors.lastname: Xue
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Weiliang
authors.initials: W
authors.lastname: Wang
mesh_terms: D018533:Biomass; D002244:Carbon / Q000032:analysis; D015118:Eicosapentaenoic Acid / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D006017:Glycolipids / Q000032:analysis; D058086:Microalgae / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000494:pharmacology*; D010743:Phospholipids / Q000032:analysis; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D006017:Glycolipids; D010743:Phospholipids; D014280:Triglycerides; D002244:Carbon; D015118:Eicosapentaenoic Acid; D009584:Nitrogen
keywords: EPA; Fatty acid composition; Nannochloropsis oceanica IMET1; Nitrogen limitation; TAG