Recycling of food wastes using bacterial chemotaxis

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K19167
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 41:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Hashimoto Wataru 京都大学, 農学研究科, 教授 (30273519)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: アルギン酸 / 細菌 / 資源化 / 食品廃棄物 / 走化性 / 多糖 / ペクチン / X線結晶構造解析

Outline of Final Research Achievements

Sphingomonas sp. strain A1 cells show alginate/pectin-assimilating ability and chemotaxis towards both plant polysaccharides. In this study, strain A1 cells were found to show chemotaxis towards food wastes such as brown algae producing alginate and mandarin orange peels containing pectin. Strain A1 cell-surface pectin-binding protein crucial for expression of chemotaxis exhibited a bifunctional ability for pectin assimilation as well as chemotaxis, and adopted several conformations with different open/closed ratios of two domains in its molecule. Strain A1 cells showing chemotaxis towards alginate and pectin produced biofuel from the above-described food wastes. This study contributes to formation of sustainable and carbon neutral societies, and achievement of sustainable development goals (SDGs).

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究により、これまでの低分子物質とは異なり、高分子物質（多糖ペクチン）に対する細菌の走化性発現に関わる新たな分子機構が明らかになった。特に、ペクチン結合タンパク質が基質のサイズに応じて親和性と結合様式を変化させることは、タンパク質の構造機能相関の観点から意義深い。また、アルギン酸とペクチンに対して資化性と走化性を示す細菌を用いて、食品廃棄物からバイオ燃料を生産できることが示されたため、循環型社会や脱炭素社会の形成［持続可能な開発目標（SDGs）の達成］に貢献できる。