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Ciclo redox de Fe (II) y Fe (III) en la magnetita por las bacterias que metabolizan el Fe
James M Byrne1, Nicole Klueglein2, Carolyn Pearce3
1Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, Sigwartstrasse 10, 72076 Tuebingen, Germany. James.Byrne@uni-tuebingen.de.
Science (New York, N.Y.)
|March 28, 2015
Resumen
Los microbios pueden usar nanopartículas de magnetita como una batería natural. Una bacteria oxida la magnetita usando luz, y otra la reduce, mostrando el intercambio de electrones en entornos cambiantes.
Área de la Ciencia:
- Microbiología ambiental microbiología ambiental.
- La geoquímica es la geoquímica.
- Los ciclos biogeoquímicos son ciclos biogeoquímicos.
Sus antecedentes:
- Los microorganismos impulsan el ciclo redox del hierro en los entornos.
- Las bacterias utilizan Fe (II) y Fe (III) de los minerales de hierro para su crecimiento.
- El intercambio de electrones en óxidos de hierro de valencia mixta entre diferentes metabolismos microbianos no se entiende bien.
Objetivo del estudio:
- Para investigar la transferencia de electrones en óxidos de hierro de valencia mixta entre bacterias con diferentes metabolismos.
- Para determinar si las nanopartículas de magnetita pueden servir como fuentes de electrones y sumideros para procesos microbianos.
Principales métodos:
- Se utilizaron mediciones magnéticas y espectroscópicas para analizar las nanopartículas de magnetita.
- Los experimentos de co-cultivo se llevaron a cabo con Rhodopseudomonas palustris TIE-1 y Geobacter sulfurreducens.
Principales resultados:
- La bacteria fototrófica Rhodopseudomonas palustris TIE-1 oxida las nanopartículas de magnetita utilizando la energía de la luz.
- Este proceso de oxidación es reversible por la bacteria reductora de Fe (((III) anaeróbica Geobacter sulfurreducens en cocultivos.
- Los iones de hierro en la magnetita cristalina son biodisponibles como donantes y aceptadores de electrones.
Conclusiones:
- Las nanopartículas de magnetita funcionan como una batería de origen natural, facilitando la transferencia de electrones microbianos.
- Esto demuestra un mecanismo de intercambio de electrones en óxidos de hierro de valencia mixta bajo condiciones ambientales cambiantes.
- La utilización microbiana de la magnetita pone de relieve su papel en los procesos redox ambientales.
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