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Producción generalizada de superóxido extracelular por las bacterias heterotróficas
Julia M Diaz1, Colleen M Hansel, Bettina M Voelker
1School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
Science (New York, N.Y.)
|May 4, 2013
Resumen
Las bacterias heterotróficas son una fuente importante de superóxido, una especie reactiva de oxígeno (ROS), en entornos sin luz. Este hallazgo impacta nuestra comprensión de la química de las profundidades oceánicas y el ciclo elemental.
Área de la Ciencia:
- Microbiología Microbiología.
- Biogeoquímica La biogeoquímica es la bioquímica.
- Oceanografía La oceanografía es la oceanografía.
Sus antecedentes:
- Las especies reactivas de oxígeno (ROS), incluido el superóxido, influyen en los ciclos elementales como el carbono y los metales traza.
- Las fuentes conocidas de ROS son dependientes de la luz, por lo que la producción en las profundidades del océano es un misterio.
- El océano profundo es un sitio importante para la regeneración de nutrientes y la exportación de carbono.
Objetivo del estudio:
- Para identificar la fuente de la misteriosa producción de ROS en entornos afóticos (sin luz).
- Para investigar el papel de las bacterias heterotróficas en la generación de superóxido.
- Para explorar las implicaciones de los ciclos de ROS en las profundidades del océano.
Principales métodos:
- Investigó la producción de superóxido en diversas bacterias heterotróficas de entornos acuáticos y terrestres.
- Se centró en una bacteria modelo del clado Roseobacter.
- Se analizó el papel de la oxidoreductasa extracelular y el dinucleótido de nicotinamida adenina (NADH) en la producción de superóxido.
Principales resultados:
- Diversas bacterias heterotróficas son una fuente significativa e independiente de la luz de superóxido.
- La producción de superóxido en Roseobacter implica una oxidorreductaza extracelular estimulada por NADH.
- Este mecanismo muestra homología con los sistemas eucariotas.
Conclusiones:
- Las bacterias heterotróficas son una fuente no reconocida de ROS en zonas afóticas.
- La producción bacteriana de ROS tiene implicaciones significativas para los ciclos biogeoquímicos del océano profundo.
- Se necesita más investigación para comprender el control de los ROS en la remineralización del carbono y la biodisponibilidad del metal.
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