title: Regulation of starch and lipid accumulation in a microalga Chlorella sorokiniana.
abstract: Microalgae have attracted growing attention due to their potential in biofuel feedstock production. However, current understanding of the regulatory mechanisms for lipid biosynthesis and storage in microalgae is still limited. This study revealed that the microalga Chlorella sorokiniana showed sequential accumulation of starch and lipids. When nitrogen was replete and/or depleted over a short period, starch was the predominant carbon storage form with basal levels of lipid accumulation. After prolonged nitrogen depletion, lipid accumulation increased considerably, which was partially due to starch degradation, as well as the turnover of primary metabolites. Lipid accumulation is also strongly dependent on the linear electron flow of photosynthesis, peaking at lower light intensities. Collectively, this study reveals a relatively clear regulation pattern of starch and lipid accumulation that is basically controlled by nitrogen levels. The mixotrophic growth of C. sorokiniana shows promise for biofuel production in terms of lipid accumulation in the final biomass.
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.affiliation: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Gargouri
authors.affiliation: Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.affiliation: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Jeong-Jin
authors.initials: JJ
authors.lastname: Park
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Difeng
authors.initials: D
authors.lastname: Gao
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Miao
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Dong
authors.affiliation: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6120, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Gang
authors.affiliation: Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA. Electronic address: chens@wsu.edu.
authors.forename: Shulin
authors.initials: S
authors.lastname: Chen
mesh_terms: D002708:Chlorella / Q000378:metabolism* / Q000502:physiology; D008027:Light; D050356:Lipid Metabolism; D058086:Microalgae / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis; D013213:Starch / Q000378:metabolism*
chemical_list: D013213:Starch; D009584:Nitrogen
keywords: Chlorella sorokiniana; Lipids; Microalgae; Starch