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Molecular biological study on the mechanism of a novel Fe^<2+>-dependent mercury reducing system of a mercury resistant iron-oxidizing bacterium

抗汞铁氧化菌新型Fe^2依赖性汞还原系统机制的分子生物学研究

基本信息

批准号：
16580059
负责人：
SUGIO Tsuyoshi
金额：
$ 2.43万
依托单位：
OKAYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

Mercury is highly toxic for almost all organisms and thus, the removal of mercury from mercury polluted soil and wastewater is a worldwide problem. The final goal of this research project is volatilization and recovery of toxic mercury compounds from mercury polluted soil and wastewater using a highly mercury-resistant iron-oxidizing bacterium A.ferrooxidans strain MON-1. Acidithiobacillus ferrooxidans strain MON-1 is a highly mercury resistant strain that can grow in an iron medium (pH 2.5) with 20 μM mercuric chloride. Author has reported that strain MON-1 has a novel Fe^<2+>-dependent mercury volatilization enzyme system as well as a NADPH-dependent mercury reductase in the cells. In section 1, author analyzed for the first time the Fe^<2+>-dependent mercury volatilization system with TMPD as an electron donor for mercury volatilization reaction. It was found that strain MON-1 cells can volatilize Hg^0 with TMPD as an electron donor under anaerobic conditions and the activity was completely inhibited by 1 mM KCN, indicating that cytochrome c oxidase is involved in Hg^0 volatilization. Author isolated cytochrome c oxidase from MON-1 cells. A highly purified MON-1 cytochrome c oxidase could volatilize Hg^0 more rapidly when TMPD was used as electron donor compared with Fe^<2+>.There have been no reports on A.ferrooxidans strains resistant to organomercurial compounds probably because there has been no report on the organomercurial lyase gene (merB) in the bacterium. In section 2, author shows for the first time that the resting cells and the cytosol from strain MON-1, the most resistant to the organomercurial compounds among the 11 strains of A.ferrooxidans tested, had organomercurial lyase-like activity which catalyzed the volatilization of Hg^0 from the reaction mixture in the presence of NADPH, β-mercaptoethanol and the intrinsic mercuric reductase.

汞对几乎所有生物体都有剧毒，因此，从汞污染的土壤和废水中去除汞是一个世界性的问题。本研究项目的最终目标是使用高抗汞铁氧化细菌A.ferrooxidans菌株MON-1从汞污染土壤和废水中挥发和回收有毒汞化合物。嗜酸氧化亚铁硫杆菌MON-1菌株是一株高抗汞的菌株，能在含20 μM氯化汞的铁培养基（pH 2.5）中生长。作者报道了MON-1菌株在细胞中具有一个新的依赖Fe^<2+>的汞挥发酶系统和一个依赖NADPH的汞还原酶。在第一部分中，作者首次分析了以TMPD为电子给体的Fe^<2+>依赖的汞挥发体系。结果表明，在厌氧条件下，菌株MON-1细胞能以TMPD为电子供体挥发Hg^0，且该活性可被1 mM KCN完全抑制，表明细胞色素c氧化酶参与了Hg^0的挥发。作者从MON-1细胞中分离出细胞色素c氧化酶。以TMPD为电子供体时，高纯度的MON-1细胞色素c氧化酶比以Fe^<2+>为电子供体时能更快地挥发出Hg^0。目前还没有氧化亚铁硫杆菌对有机汞化合物产生抗性的报道，可能是因为还没有关于该菌中有机汞裂解酶基因（merB）的报道。在第二部分中，作者首次发现在11株氧化亚铁不动杆菌中对有机汞化合物抗性最强的菌株MON-1的静息细胞和胞浆具有类有机汞裂解酶活性，在NADPH、β-巯基乙醇和内源汞还原酶存在下，该酶能催化Hg^0从反应混合物中挥发。

项目成果

期刊论文数量（36）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Existence of an iron-oxidizing bacterium Acidithiobacillus ferrooxidans resistant to organomercurials compounds

对有机汞化合物具有抗性的铁氧化细菌氧化亚铁硫杆菌的存在

DOI：
发表时间：
2005
期刊：
J.Biosci.Bioeng. 99
影响因子：
0
作者：
F.Takeuchi;A.Negishi;T.S.Nakamura;K.Kamimura;T.Sugo
通讯作者：
T.Sugo

A new bench scale restoration method for a mercury polluted soil with a mercury resistant Acidithiobacillus ferrooxidans

抗汞氧化亚铁硫杆菌修复汞污染土壤的新方法

DOI：
发表时间：
2004
期刊：
In Biohydrometallurgy : a sustainable technology in evolution (Marios Tsezos et al. eds.)
影响因子：
0
作者：
A.Negishi;T.Maeda;F.Takeuchi;K.Kamimura;T.Sugio
通讯作者：
T.Sugio

Isolation and some properties of sulfur dioxygenase from Acidithiobacillus thiooxidans NB1-3(Harrion, S.T.L, Rawlings, D.E.. and J.Petersen, J. eds.)(Compress w.w.w. compress. co. za. Cape Town, South Africa)

硫氧化硫杆菌 NB1-3 中硫双加氧酶的分离和一些特性（Harrion, S.T.L, Rawlings, D.E.. 和 J.Petersen, J. eds.）（Compress w.w.w. compress. co. za. 开普敦，南非）