Development of biodegradable plastic production technology using PET as fermentation feedstock

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19151
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Yoshida Shosuke 奈良先端科学技術大学院大学, 先端科学技術研究科, 教授 (80610766)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: ポリヒドロキシアルカン酸 / PET / Ideonella sakaiensis

Outline of Final Research Achievements

I. sakaiensis, a polyethylene terephthalate (PET) degrading and metabolizing bacterium, accumulates significant amounts of polyhydroxyalkanoic acid (PHA) in its body using PET as a fermentation feedstock. In this study, we aimed to improve the PHA production and PHA properties of I. sakaiensis. We conducted the study focusing on the fact that I. sakaiensis grows well on PET as a carbon source and accumulates significant amounts of PHA, but the cell yield grown on terephthalic acid or ethylene glycol as a carbon source is low and produces little PHA. As a result, we found that I. sakaiensis preferentially uptakes MHET and were able to increase PHA production by adding MHET to PET in the medium.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

I. sakaiensisによるPETを発酵原料としたの実装化には、菌体収率の向上が求められる。本研究で、本菌がPET代謝時に菌体外から取り込む基質を同定した。そして、この発見を利用することでPHAの増産に成功し、実装化への重要な知見を得ることができた。今後、本知見に基づくさらなる条件の最適化や、PHA共重合体の生産株を利用することで、実用化に耐えうるレベルへの収率の向上を進める必要がある。