Role of Mer transporters in the transport of toxic metals and rare metal in Escherichia coli and usability for environmental purification.

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K06664
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 47030:Pharmaceutical hygiene and biochemistry-related
• Research Institution: Kitasato University
• Principal Investigator: Ohshiro Yuka 北里大学, 薬学部, 助教 (60550035)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 水銀耐性遺伝子 / 金属輸送活性 / 希少金属 / 金属汚染浄化

Outline of Final Research Achievements

The characteristics of bacteria take up mercury into cells via Mer superfamily, i.e., MerC, MerE, MerF, MerT, or MerP, have been applied in engineering of bioreactor used for phytoremediation. Our objective was to clarify individual role of MerC, MerE, MerF, MerT, or MerP and potential in transport of toxic metals and rare metals. The E. coli cells that carried mer recombinants were treated with Cu, Au, or Sb. MerC or MerT+MerP recombinants accumulated significantly more Cu and Au than control. The cells that expressed MerC, MerE, MerF, or MerT accumulated significantly more Sb than control. Consequently, we demonstrated that MerC, MerE, MerF, and MerT are broad-spectrum metals transporters. Our results suggested that MerC is the most efficient tool and it was expected that not only the purification of toxic metal pollution but also the recovery of rare metals could be achieved.

Free Research Field

環境薬学

Academic Significance and Societal Importance of the Research Achievements

近年、水銀等の有害金属や希少金属を含む電気電子機器廃棄物の不適切な処理により、特に途上国において環境が汚染され健康リスクが高まっている。土壌浄化の社会的需要の増加に伴い、経済的で環境負荷の少ない「植物による環境浄化」に注目が集まっているが、浄化期間の長さや効率に課題を抱えている。本研究から、微生物由来のMer輸送体が有害金属、貴金属、希少金属の取り込み活性を持つことが明らかとなり、Mer輸送体は植物による環境浄化の課題の克服の切り札となると期待される。また、希少金属の回収に利用することで、国際的な価格高騰が問題となり、先端産業の必須材料である希少金属の新たな供給源の確保に繋がると考えられる。