Studies on the mechanism for colony formation by the hydrocarbon producing green microalga Botryococcus braunii

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03043
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 40040:Aquatic life science-related
• Research Institution: The University of Tokyo
• Principal Investigator: Okada Shigeru 東京大学, 大学院農学生命科学研究科(農学部), 准教授 (00224014)
• Co-Investigator(Kenkyū-buntansha): 松永 茂樹 東京大学, 大学院農学生命科学研究科(農学部), 教授 (60183951)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: Botryococcus braunii / 脂肪酸 / バイオポリマー / 群体 / バイオ燃料

Outline of Final Research Achievements

The green microalga Botryococcus braunii produces a lot of liquid hydrocarbons that can be used as alternative biofuels for petroleum. The alga also produces biopolymers to form algal colonies in which cells are embeded together. The biopolymer is, however, troublesome for the effective utilization of this algal species because it hampers easy recovery of hydrocarbons by trapping them. The biopolymer is derived from the long chain fatty aldehyde. Then the mechanism of the long chain fatty aldehyde biosynthesis was studied. Transcriptome analyses on the alga showed that unique fatty acid synthase-like genes are expressing in addition to the conventional plant-type fatty acid synthase genes. The unique fatty acid synthase-like protein seem to be responsible for the formation of the long chain fatty aldehyde. Thus characterization of enzymatic functions of the genes was tried by the heterologous gene expression system using yeast cells as the host.

Free Research Field

水圏天然物化学

Academic Significance and Societal Importance of the Research Achievements

本研究により、バイオ燃料源として期待されている微細緑藻Botryococcus brauniiには、通常の植物プランクトンには存在しない、ユニークな脂肪酸合成酵素様タンパク質が存在することを示す事ができた。当該タンパク質の酵素学的機能を明らかにすることで、将来的にはバイオ燃料となる炭化水素の回収が、より容易な新藻株の作出等が期待できる。