title: Coordinated response of photosynthesis, carbon assimilation, and triacylglycerol accumulation to nitrogen starvation in the marine microalgae Isochrysis zhangjiangensis (Haptophyta).
abstract: The photosynthetic performance, carbon assimilation, and triacylglycerol accumulation of Isochrysis zhangjiangensis under nitrogen-deplete conditions were studied to understand the intrinsic correlations between them. The nitrogen-deplete period was divided into two stages based on the photosynthetic parameters. During the first stage, carbon assimilation was not reduced compared with that under favorable conditions. The marked increase in triacylglycerols and the variation in the fatty acid profile suggested that triacylglycerols were mainly derived from de novo synthesized acyl groups. In the second stage, the triacylglycerol content continued increasing while the carbohydrate content decreased from 44.0% to 26.3%. These results indicated that the intracellular conversion of carbohydrates to triacylglycerols occurred. Thus, we propose that sustainable carbon assimilation and incremental triacylglycerol production can be achieved by supplying appropriate amounts of nitrogen in medium to protect the photosynthetic process from severe damage using the photosynthetic parameters as indicators.
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Wang
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Meng
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Xu-Peng
authors.initials: XP
authors.lastname: Cao
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Jiang-Ning
authors.initials: JN
authors.lastname: Ai
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Jian-Nan
authors.initials: JN
authors.lastname: Zhou
authors.affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Electronic address: xuesong@dicp.ac.cn.
authors.forename: Song
authors.initials: S
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Wei-liang
authors.initials: WL
authors.lastname: Wang
mesh_terms: D059001:Aquatic Organisms / Q000187:drug effects / Q000378:metabolism*; D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D057486:Carbon Cycle / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D058087:Haptophyta / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D058086:Microalgae / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D045332:Photosystem II Protein Complex; D014280:Triglycerides; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen
keywords: Isochrysis zhangjiangensis; Nitrogen limitation; Photosynthesis; Triacylglycerols production