Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths
Bacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II) to Fe(III) and/or active groups of bacterial exopolymers within sheaths to attract and bind aqu...
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| Format: | Article |
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MDPI AG
2016-06-01
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| Series: | Biology |
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| Online Access: | http://www.mdpi.com/2079-7737/5/2/26 |
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| author | Tatsuki Kunoh Hideki Hashimoto Ian R. McFarlane Naoaki Hayashi Tomoko Suzuki Eisuke Taketa Katsunori Tamura Mikio Takano Mohamed Y. El-Naggar Hitoshi Kunoh Jun Takada |
| author_facet | Tatsuki Kunoh Hideki Hashimoto Ian R. McFarlane Naoaki Hayashi Tomoko Suzuki Eisuke Taketa Katsunori Tamura Mikio Takano Mohamed Y. El-Naggar Hitoshi Kunoh Jun Takada |
| author_sort | Tatsuki Kunoh |
| collection | DOAJ |
| description | Bacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II) to Fe(III) and/or active groups of bacterial exopolymers within sheaths to attract and bind aqueous-phase inorganics. When L. cholodnii SP-6 cells were cultured in media amended with high Fe(II) concentrations, Fe(III) precipitates visibly formed immediately after addition of Fe(II) to the medium, suggesting prompt abiotic oxidation of Fe(II) to Fe(III). Intriguingly, these precipitates were deposited onto the sheath surface of bacterial cells as the population was actively growing. When Fe(III) was added to the medium, similar precipitates formed in the medium first and were abiotically deposited onto the sheath surfaces. The precipitates in the Fe(II) medium were composed of assemblies of globular, amorphous particles (ca. 50 nm diameter), while those in the Fe(III) medium were composed of large, aggregated particles (≥3 µm diameter) with a similar amorphous structure. These precipitates also adhered to cell-free sheaths. We thus concluded that direct abiotic deposition of Fe complexes onto the sheath surface occurs independently of cellular activity in liquid media containing Fe salts, although it remains unclear how this deposition is associated with the previously proposed mechanisms (oxidation enzyme- and/or active group of organic components-involved) of Fe encrustation of the Leptothrix sheaths. |
| first_indexed | 2024-03-12T07:05:35Z |
| format | Article |
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| issn | 2079-7737 |
| language | English |
| last_indexed | 2024-03-12T07:05:35Z |
| publishDate | 2016-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biology |
| spelling | doaj.art-d1734bbbd98540acba095ea9b8d059cc2023-09-02T23:28:28ZengMDPI AGBiology2079-77372016-06-01522610.3390/biology5020026biology5020026Abiotic Deposition of Fe Complexes onto Leptothrix SheathsTatsuki Kunoh0Hideki Hashimoto1Ian R. McFarlane2Naoaki Hayashi3Tomoko Suzuki4Eisuke Taketa5Katsunori Tamura6Mikio Takano7Mohamed Y. El-Naggar8Hitoshi Kunoh9Jun Takada10Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanDepartment of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USACore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanDepartment of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USACore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanCore Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-0082, JapanBacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II) to Fe(III) and/or active groups of bacterial exopolymers within sheaths to attract and bind aqueous-phase inorganics. When L. cholodnii SP-6 cells were cultured in media amended with high Fe(II) concentrations, Fe(III) precipitates visibly formed immediately after addition of Fe(II) to the medium, suggesting prompt abiotic oxidation of Fe(II) to Fe(III). Intriguingly, these precipitates were deposited onto the sheath surface of bacterial cells as the population was actively growing. When Fe(III) was added to the medium, similar precipitates formed in the medium first and were abiotically deposited onto the sheath surfaces. The precipitates in the Fe(II) medium were composed of assemblies of globular, amorphous particles (ca. 50 nm diameter), while those in the Fe(III) medium were composed of large, aggregated particles (≥3 µm diameter) with a similar amorphous structure. These precipitates also adhered to cell-free sheaths. We thus concluded that direct abiotic deposition of Fe complexes onto the sheath surface occurs independently of cellular activity in liquid media containing Fe salts, although it remains unclear how this deposition is associated with the previously proposed mechanisms (oxidation enzyme- and/or active group of organic components-involved) of Fe encrustation of the Leptothrix sheaths.http://www.mdpi.com/2079-7737/5/2/26Leptothrix cholodnii SP-6abiotic oxidationFe(III) particlessheathdirect deposition |
| spellingShingle | Tatsuki Kunoh Hideki Hashimoto Ian R. McFarlane Naoaki Hayashi Tomoko Suzuki Eisuke Taketa Katsunori Tamura Mikio Takano Mohamed Y. El-Naggar Hitoshi Kunoh Jun Takada Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths Biology Leptothrix cholodnii SP-6 abiotic oxidation Fe(III) particles sheath direct deposition |
| title | Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths |
| title_full | Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths |
| title_fullStr | Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths |
| title_full_unstemmed | Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths |
| title_short | Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths |
| title_sort | abiotic deposition of fe complexes onto leptothrix sheaths |
| topic | Leptothrix cholodnii SP-6 abiotic oxidation Fe(III) particles sheath direct deposition |
| url | http://www.mdpi.com/2079-7737/5/2/26 |
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