Volatilization of Mercury by an Iron Oxidation Enzyme System in a Highly Mercury-resistant<i>Acidithiobacillus ferrooxidans</i>Strain MON-1

• SUGIO Tsuyoshi

  <i>Graduate School of Natural Science and Technology, Science and Technology for Energy Conversion, Okayama University</i>

• FUJII Mitsuko

  <i>Graduate School of Natural Science and Technology, Science and Technology for Energy Conversion, Okayama University</i>

• TAKEUCHI Fumiaki

  <i>Administration Center for Environmental Science and Technology, Okayama University</i>

• NEGISHI Atsunori

  <i>Technical Research Institute, Hazama Corporation</i>

• MAEDA Terunobu

  <i>Civil Chemical Engineering Corporation</i>

• KAMIMURA Kazuo

  <i>Graduate School of Natural Science and Technology, Science and Technology for Energy Conversion, Okayama University</i>

書誌事項

タイトル別名

• Volatilization of Mercury by an Iron Oxidation Enzyme System in a Highly Mercury-resistant Acidithiobacillus ferrooxidans Strain MON-1

抄録

  A highly mercury-resistant strain Acidithiobacillus ferrooxidans MON-1, was isolated from a culture of a moderately mercury-resistant strain, A. ferrooxidans SUG 2-2 (previously described as Thiobacillus ferrooxidans SUG 2-2), by successive cultivation and isolation of the latter strain in a Fe²⁺ medium with increased amounts of Hg²⁺ from 6 μM to 20 μM. The original stain SUG 2-2 grew in a Fe²⁺ medium containing 6 μM Hg²⁺ with a lag time of 22 days, but could not grow in a Fe²⁺ medium containing 10 μM Hg²⁺. In contrast, strain MON-1 could grow in a Fe²⁺ medium containing 20 μM Hg²⁺ with a lag time of 2 days and the ability of strain MON-1 to grow rapidly in a Fe²⁺ medium containing 20 μM Hg²⁺ was maintained stably after the strain was cultured many times in a Fe²⁺ medium without Hg²⁺. A similar level of NADPH-dependent mercury reductase activity was observed in cell extracts from strains SUG 2-2 and MON-1. By contrast, the amounts of mercury volatilized for 3 h from the reaction mixture containing 7 μM Hg²⁺ using a Fe²⁺-dependent mercury volatilization enzyme system were 5.6 nmol for SUG 2-2 and 67.5 nmol for MON-1, respectively, indicating that a marked increase of Fe²⁺-dependent mercury volatilization activity conferred on strain MON-1 the ability to grow rapidly in a Fe²⁺ medium containing 20 μM Hg²⁺. Iron oxidizing activities, 2,3,5,6-tetramethyl-p-phenylenediamine (TMPD) oxidizing activities and cytochrome c oxidase activities of strains SUG 2-2 and MON-1 were 26.3 and 41.9 μl O₂ uptake/mg/min, 15.6 and 25.0 μl O₂ uptake/mg/min, and 2.1 and 6.1 mU/mg, respectively. These results indicate that among components of the iron oxidation enzyme system, especially cytochrome c oxidase activity, increased by the acquisition of further mercury resistance in strain MON-1. Mercury volatilized by the Fe²⁺-dependent mercury volatilization enzyme system of strain MON-1 was strongly inhibited by 1.0 mM sodium cyanide, but was not by 50 nM rotenone, 5 μM 2-n-heptyl-4-hydroxy-quinoline-N-oxide (HQNO), 0.5 μM antimycin A, or 0.5 μM myxothiazol, indicating that cytochrome c oxidase plays a crucial role in mercury volatilization of strain MON-1 in the presence of Fe²⁺.<br>

収録刊行物

• Ｂｉｏｓｃｉｅｎｃｅ，　Ｂｉｏｔｅｃｈｎｏｌｏｇｙ，　ａｎｄ　Ｂｉｏｃｈｅｍｉｓｔｒｙ

  Ｂｉｏｓｃｉｅｎｃｅ，　Ｂｉｏｔｅｃｈｎｏｌｏｇｙ，　ａｎｄ　Ｂｉｏｃｈｅｍｉｓｔｒｙ 67 (7), 1537-1544, 2003

  公益社団法人 日本農芸化学会

キーワード

• iron-oxidizing bacterium
• <i>Acidithiobacillus ferrooxidans</i>
• mercury resistance
• mercury reduction
• cytochrome <i>c</i> oxidase

詳細情報

• CRID: 1390001206473699328
• NII論文ID: 110002694260
• NII書誌ID: AA10824164
• DOI: 10.1271/bbb.67.1537
• COI: 1:CAS:528:DC%2BD3sXmtFelu7Y%3D
• ISSN: 13476947
• ISSN: 09168451
• NDL書誌ID: 6622113
• PubMed: 12913298
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6622113
• Web Site: http://www.tandfonline.com/doi/pdf/10.1271/bbb.67.1537
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可