ヒ素高蓄積植物による土壌ヒ素の吸収・除去と土壌微生物の亜ヒ酸酸化に関する研究  [in Japanese] Study on the Arsenic Absorption and Removal from the Soil by Arsenic Hyper-Accumulator and Arsenite Oxidation by Soil Bacteria  [in Japanese]

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Abstract

モエジマシダ(Pteris vittata)等のヒ素高蓄積植物はヒ素土壌汚染の浄化に適用可能と考えられている.本研究では, モエジマシダを用いたヒ素のファイトエクストラクション法による浄化技術に着目し, それによるヒ素吸収における微生物の関与の度合いを明らかにすることを目的として行った. 微生物植種の添加に伴うシダの栽培実験と土壌ヒ素の酸化試験を行い, ヒ素の土壌からシダへの移行特徴および形態変化を解析した. その結果, 土壌中の亜ヒ酸はヒ酸に酸化されたのち, その多くはシダにより吸収されることと, このヒ素酸化は微生物による作用であることが強く示された. さらに, シダ根圏試料に対して亜ヒ酸酸化酵素遺伝子aroAをターゲットとしたT-RFLP解析より, シダによるヒ素吸収に先立つヒ素形態の変化には, 土壌中のaroAを有する微生物が関与していると示唆された.

 Arsenic hyper-accumulators such as Pteris vittata have been known applicable to purify arsenic pollution from the soil. The present study focuses on the phytoextraction of arsenic and aims to clarify the participation of microbes in the arsenic absorption by Pteris vittata. The cultivation experiments of Pteris vittata have been performed to investigate the transition of arsenic from the soil to Pteris vittata. The results show that the arsenite in the soil is promptly oxidized to arsenate and subsequently absorbed by Pteris vittata. The arsenic oxidation experiment in the soil with soil bacteria addition has been peformed, and the speciation of arsenic in the soil has been investigated. The results suggest that soil bacteria are responsible for the arsinite oxidation. T-RFLP analysis targeting to arsenite oxidase genes, aroAs, has been applied to analyze the microbial community in the rhizoshpere of Pteris vittata. The results suggest that specific aroA containing bacterial strains are involved in the arsenite oxidation prior to being absorbed by Pteris vittata.

Journal

  • Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research)

    Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research) 69(7), III_9-III_15, 2013

    Japan Society of Civil Engineers

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