title: Genetic improvement of the microalga Phaeodactylum tricornutum for boosting neutral lipid accumulation.
abstract: To obtain fast growing oil-rich microalgal strains has been urgently demanded for microalgal biofuel. Malic enzyme (ME), which is involved in pyruvate metabolism and carbon fixation, was first characterized in microalgae here. Overexpression of Phaeodactylum tricornutum ME (PtME) significantly enhanced the expression of PtME and its enzymatic activity in transgenic P. tricornutum. The total lipid content in transgenic cells markedly increased by 2.5-fold and reached a record 57.8% of dry cell weight with a similar growth rate to wild type, thus keeping a high biomass. The neutral lipid content was further increased by 31% under nitrogen-deprivation treatment, still 66% higher than that of wild type. Transgenic microalgae cells exhibited obvious morphological changes, as the cells were shorter and thicker and contained larger oil bodies. Immuno-electron microscopy targeted PtME to the mitochondrion. This study markedly increased the oil content in microalgae, suggesting a new route for developing ideal microalgal strains for industrial biodiesel production.
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Xue
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China.
authors.forename: Ying-Fang
authors.initials: YF
authors.lastname: Niu
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China.
authors.forename: Tan
authors.initials: T
authors.lastname: Huang
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Yang
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China.
authors.forename: Jie-Sheng
authors.initials: JS
authors.lastname: Liu
authors.affiliation: Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou 510632, China. Electronic address: thyli@jnu.edu.cn.
authors.forename: Hong-Ye
authors.initials: HY
authors.lastname: Li
mesh_terms: D020418:Algal Proteins / Q000096:biosynthesis / Q000235:genetics; D017377:Diatoms / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D005818:Genetic Engineering / Q000379:methods*; D050356:Lipid Metabolism; D008291:Malate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000378:metabolism
chemical_list: D020418:Algal Proteins; D008291:Malate Dehydrogenase
keywords: Biodiesel; Lipid; Malic enzyme; Microalga