title: Metabolic changes of starch and lipid triggered by nitrogen starvation in the microalga Chlorella zofingiensis.
abstract: The aim of this research was to study the metabolic changes of starch and lipid biosynthesis in the microalga Chlorella zofingiensis under nitrogen starvation in comparison to nitrogen abundant condition. C. zonfingiensis showed a rapid growth and kept stable chlorophyll content when grown in nitrogen-replete medium, while a severe inhibition of cell growth and a sharp degradation of chlorophyll occurred under nitrogen depletion. Nitrogen-replete C. zonfingiensis cells possessed basal levels of starch and lipid. Upon nitrogen starvation, both starch and lipid increased greatly within cells, but starch synthesis preceded lipid accumulation. After 2 days of stress condition, starch was partially degraded, possibly to support lipid synthesis. It was speculated that starch accumulation acted as a quick response to environmental stress, whereas lipid served as long-term energy storage. Additionally, C. zonfingiensis tends to lower the degree of unsaturation in response to nitrogen starvation which is desirable for biodiesel production.
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Shunni
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jingliang
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: yuanzh@ms.giec.ac.cn.
authors.forename: Zhenhong
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D018533:Biomass; D002708:Chlorella / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D002734:Chlorophyll / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis; D050356:Lipid Metabolism / Q000187:drug effects*; D058086:Microalgae / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000172:deficiency* / Q000494:pharmacology*; D013213:Starch / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D005227:Fatty Acids; D009566:Nitrates; D002734:Chlorophyll; D013213:Starch; D009584:Nitrogen
keywords: Biofuels; Chlorella zofingiensis; Fatty acids; Nitrogen starvation; Starch