Challenge to dechlorinate polychlorinated biphenyls under aerobic conditions with an engineered reductive dehalogenase

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19881
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 64:Environmental conservation measure and related fields
• Research Institution: Kyoto University
• Principal Investigator: Takatsuka Yumiko 京都大学, エネルギー理工学研究所, 特定准教授 (70570810)
• Co-Investigator(Kenkyū-buntansha): 原 富次郎 京都大学, エネルギー理工学研究所, 特定教授 (70616193)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: ポリ塩化ビフェニル / 還元的脱塩素化酵素 / 遺伝子組換え細菌 / ビタミンB12 / Dehalococcoides

Outline of Final Research Achievements

The reductive dechlorination of polychlorinated biphenyls (PCBs) in an anaerobic environment is desired to be applied to bioremediation techniques. In an attempt to create an innovative biocatalyst that "dechlorinates PCBs under aerobic conditions," we have constructed a recombinant bacterial strain that expresses PCBs dehalogenase of a strictly anaerobic bacterium, Dehalococcoides. In addition, in an anaerobic model in which PCBs were added to groundwater collected from the PCBs-contaminated site, which was prepared to investigate the optimum conditions for the reductive dechlorination, a remarkable decrease in PCBs concentration and the presence of two anaerobic PCBs-dechlorinating bacteria were shown.

Free Research Field

応用微生物学、微生物生化学

Academic Significance and Societal Importance of the Research Achievements

「高塩素型PCBsを好気的条件下で脱塩素化する新機能酵素の創出」は極めて挑戦的であり、国際的なPCBs浄化に喫緊な需要ある技術である。活性を示した遺伝子組換えPCBs脱塩素酵素の報告はまだ無く、本研究課題で作製した組換え酵素の反応を最適化し、さらに大気下で還元的脱塩素化を実現する新機能酵素を創生できれば、酸化的ビフェニル分解酵素群との併活用により、これまでにない効果的な手法で生物浄化技術にパラダイムシフトを起こすと期待できる。