title: Dynamic metabolic profiling together with transcription analysis reveals salinity-induced starch-to-lipid biosynthesis in alga Chlamydomonas sp. JSC4.
abstract: Biodiesel production using microalgae would play a pivotal role in satisfying future global energy demands. Understanding of lipid metabolism in microalgae is important to isolate oleaginous strain capable of overproducing lipids. It has been reported that reducing starch biosynthesis can enhance lipid accumulation. However, the metabolic mechanism controlling carbon partitioning from starch to lipids in microalgae remains unclear, thus complicating the genetic engineering of algal strains. We here used "dynamic" metabolic profiling and essential transcription analysis of the oleaginous green alga Chlamydomonas sp. JSC4 for the first time to demonstrate the switching mechanisms from starch to lipid synthesis using salinity as a regulator, and identified the metabolic rate-limiting step for enhancing lipid accumulation (e.g., pyruvate-to-acetyl-CoA). These results, showing salinity-induced starch-to-lipid biosynthesis, will help increase our understanding of dynamic carbon partitioning in oleaginous microalgae. Moreover, we successfully determined the changes of several key lipid-synthesis-related genes (e.g., acetyl-CoA carboxylase, pyruvate decarboxylase, acetaldehyde dehydrogenase, acetyl-CoA synthetase and pyruvate ferredoxin oxidoreductase) and starch-degradation related genes (e.g., starch phosphorylases), which could provide a breakthrough in the marine microalgal production of biodiesel.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, P.R. China.
authors.forename: Shih-Hsin
authors.initials: SH
authors.lastname: Ho
authors.affiliation: Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Nakanishi
authors.affiliation: Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yamasaki
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.|Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Jo-Shu
authors.initials: JS
authors.lastname: Chang
authors.affiliation: Department of Environmental and Life Science/Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Misawa
authors.affiliation: Department of Environmental and Life Science/Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan.
authors.forename: Yuu
authors.initials: Y
authors.lastname: Hirose
authors.affiliation: Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan.|Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Minagawa
authors.affiliation: Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hasunuma
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.|Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D000105:Acetyl Coenzyme A / Q000378:metabolism; D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D056804:Biofuels; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D002696:Chlamydomonas / Q000378:metabolism*; D020869:Gene Expression Profiling; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000032:analysis; D055432:Metabolomics; D011767:Pyruvate Decarboxylase / Q000235:genetics / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D012492:Salts / Q000494:pharmacology*; D013213:Starch / Q000378:metabolism*; D024941:Starch Phosphorylase / Q000235:genetics / Q000378:metabolism
chemical_list: D056804:Biofuels; D008055:Lipids; D012492:Salts; D000105:Acetyl Coenzyme A; D002244:Carbon; D019289:Pyruvic Acid; D013213:Starch; D024941:Starch Phosphorylase; D011767:Pyruvate Decarboxylase; D000103:Acetyl-CoA Carboxylase