Confined enzyme reaction systems mimicking carbon-fixation strategy of cell organelles

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02543
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 27040:Biofunction and bioprocess engineering-related
• Research Institution: Yamaguchi University
• Principal Investigator: Yoshimoto Makoto 山口大学, 大学院創成科学研究科, 教授 (80322246)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 酵素反応 / 炭素固定 / 気泡塔バイオリアクター / 固定化酵素 / 気液二相流

Outline of Final Research Achievements

A carbon-fixation process was developed using phosphoenolpyruvate carboxylase as an enzyme catalyst and carbon dioxide gas as a carbon source. Free carboxylase exhibited little catalytic activity in gas-liquid two-phase flow because of the adsorption of the enzyme to gas-liquid interface. On the other hand, carboxylase, which was immobilized onto the rough surface of polystyrene beads could function in the presence of bubbles because of the interaction of the enzyme with the gas-liquid interface was depressed. Based on the above findings, the reaction, in which carboxylation of phosphoenolpyruvate was catalyzed by the immobilized carboxylase beads, was induced using an external loop airlift bubble column operated with carbon dioxide-containing gas. It was also demonstrated that the catalyst beads were reusable.

Free Research Field

生物化学工学

Academic Significance and Societal Importance of the Research Achievements

エネルギー消費を抑制しながら，二酸化炭素を有効利用する技術の開発は，低炭素社会の実現に向けて有効なアプローチである。常温・常圧において炭素固定反応を触媒する酵素の機能を，実用的な反応器において安定に利用できれば，上述の観点から意義が大きい。二酸化炭素がガス状で反応器に供給される場合，気液界面における酵素の失活が問題となる。本研究では，ポリスチレン粒子に結合させた酵素が，気泡群が共存する反応器において，二酸化炭素ガスを原料とした炭素固定反応を安定に促進することを見出した。また，触媒粒子は反応器から回収して次の反応に再利用できるため，実用的にも優れたプロセスを構築できる。