Development of a highly active metabolic system using synthetic microbial consortium

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14546
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 27040:Biofunction and bioprocess engineering-related
• Research Institution: Kyushu University
• Principal Investigator: Soma Yuki 九州大学, 農学研究院, 助教 (80781955)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 合成生物学 / 代謝工学 / 進化工学 / 細菌叢

Outline of Final Research Achievements

In this study, we developed a novel enzyme screening method employed “synthetic microbial consortium”, which facilitates enzyme activity assay using their growth rate as a selection index. We constructed a synthetic microbial consortium using amino acid auxotroph strains which can grow by mutually donating metabolites to each other. In such system, the higher the activity of mutual donation of metabolites, the higher the rate of “co-growth” of the entire consortium. And the superiority of the activity of enzymes that contribute to the mutual donation of metabolites can be evaluated by the “co- growth” of the consortium. By introducing random mutations into the metabolic enzymes responsible for metabolite co-donation in several model bacterial flora, we obtained mutant flora with a co-proliferation rate higher than that of the wild-type flora, and in fact, the improvement in enzyme activity was confirmed.

Free Research Field

合成生物学

Academic Significance and Societal Importance of the Research Achievements

酵素進化工学において効率的に高活性酵素を獲得するには，全変異体数に対するスクリーニング系の網羅性とスループットが十分に高いことが求められる．本研究では，微生物培養液の濁度を計測するだけで簡便に標的酵素の活性を疑似的に評価する手法を開発した．これにより，プレートリーダーなどの既存設備を使用して省力・省コストでハイスループットな酵素活性スクリーニングを実現した．また，微生物の相利共生における代謝物の相互供与に関与する各種パラメータ (酵素活性・酵素発現量・菌体量比・供与代謝物利用における化学量論，等) を精密にコントロールすることで，菌叢としての表現型に与える影響を精細に解析することに成功した．