Regulation of metabolic switching in storage lipid and storage polysaccharide

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K12647
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Design and evaluation of sustainable and environmental conscious system
• Research Institution: Kanto Gakuin University (2017-2018); University of Tsukuba (2016)
• Principal Investigator: ARAIE HIROYA 関東学院大学, 理工学部, 助教 (30596169)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: アルケノン / 炭素分配 / ハプト藻 / 脂質 / 多糖 / Tisochrysis / 重イオンビーム

Outline of Final Research Achievements

Algae which use polysaccharides as energy storage need polysaccharides conversion into lipids for lipid accumulation because of the trade-off between polysaccharides and lipid. In T-Iso strains that use both polysaccharides and lipids as energy storage, we found that change of carbon flow to lipids rather than conversion of polysaccharides into lipids was important for lipid production especially alkenone production. In addition, analysis of the mutant strains suggest that intracellular C / N balance is involved in the change of carbon flow to lipids. Mutant analysis also suggests that alkenone production could be increased by inhibition TAG production. Finally, comparative genome analysis suggested that Polyketide synthase may be an alkenone synthase gene.

Free Research Field

植物代謝生理

Academic Significance and Societal Importance of the Research Achievements

脂質アルケノンは貯蔵脂質という機能が示唆されているが、同じ貯蔵物質である多糖との相互関係が分かっていなかった。また、今まで様々な培養条件が試されてきたが、アルケノンの増産は達成されていなかった。今回、変異株を用いたことで初めてアルケノン増産への道筋が見えてきた。更に、ゲノム比較解析からアルケノン合成遺伝子候補としてポリケチド合成酵素が初めて見つかった。本研究成果により、アルケノン合成の制御や遺伝子の輪郭が見え始め、アルケノンを藻類バイオ燃料として利用できる可能性が高まったといえるだろう。