学会誌「EICA」

[特集] 地下水中の塩素化エチレン分解細菌の検出

内容

バイオアッセイ

巻

9巻1号2004年

Page

21

題名

地下水中の塩素化エチレン分解細菌の検出

Title

Detection of Chlorinated Ethene-Dehalogenating Bacteria in Groundwater

著者

中村寛治(東北学院大学），上野俊洋，石田浩昭(栗田工業（株））

Authors

著者表記

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著者勤務先名

Office name

著者所属名

キーワード

Key Words

　

概要

本研究では，塩素化エチレン分解能を有するDehalococcoides属細菌がTCE，c-DCE，VC
の脱塩素化反応に深く関与していることを示すと共に，Dehalococcoides 属細菌の16S
rDNA を標的としたReal-Time PCR による定量検出法を紹介した．
また，本検出法を汚染現場に適用して，初期段階での土着Dehalococcoides 属細菌存在の確認，つまり土着細菌によるバイオスティミュレーション適用の可否判断が可能であることを示した．さらに浄化開始後，地下水中のDehalococcoides
属細菌16S rDNA濃度をモニタリングすることによって，Dehalococcoides属細菌の現場での増殖（=
分解）挙動を把握できることを明らかにした．以上の結果から，Dehalococcoides
属細菌を利用するバイオスティミュレーション技術が，管理可能なプロセスとして汚染現場で適用できる目処が得られた．

Abstract

　　Chlorinated ethenes such as tetrachloroethene (PCE) and trichloroethene
(TCE) were
widely used for dry-cleaning and degreasing, respectively. Resultantly they have become
main contaminants in groundwater. Under the anaerobic conditions, these compounds are
gradually dechlorinated by some bacteria producing their daughter products such as cisdichloroethene
(c-DCE), vinyl chloride (VC) and ethene (ETH). However, this process does
not always proceed to the end product of ETH. We sometimes observe the accumulation
of c-DCE or VC, which is a carcinogen. Our study showed that Dehalococcoides bacteria
capable of promoting the dechlorination steps beyond c-DCE were essential for complete
dechlorination. It is known that Dehalococcoides bacteria are di.cult to cultivate and isolate.
Therefore we decided to apply a molecular technique, real-time PCR, to the detection of the
bacteria. The real-time PCR method developed was successfully used for the detection of
the bacteria in groundwater. The new method was used for the judgment of the feasibility
of the biostimulation using indigenous Dehalococcoides population. Also the method was
successfully applied to the monitoring of the whole bioremediation process.