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La modificación en curso de los sapropeles del Pleistoceno Mediterráneo mediados por procariotas
Marco J L Coolen1, Heribert Cypionka, Andrea M Sass
1Paleomicrobiology Group, Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Post Office Box 2503, D-26111 Oldenburg, Germany.
Science (New York, N.Y.)
|June 29, 2002
Resumen
Los antiguos sedimentos del Mar Mediterráneo albergan comunidades microbianas activas, principalmente bacterias verdes sin azufre desconocidas y Crenarchaeota. Estos microbios son metabólicamente activos, degradando los antiguos sustratos de carbono dentro de las capas de sapropel ricas en orgánico.
Área de la Ciencia:
- Microbiología marina microbiología marina.
- La geoquímica es la geoquímica.
- La paleoceanografía es la paleoceanografía.
Sus antecedentes:
- Las sapropelas del Pleistoceno tardío en el Mar Mediterráneo oriental contienen procariotas quimioorganotróficos.
- Estas capas ricas en orgánico contrastan con los sedimentos circundantes de carbono.
Objetivo del estudio:
- Para investigar la vida microbiana y la actividad metabólica dentro de antiguas capas de sapropel.
- Para identificar los actores microbianos clave responsables del ciclo del carbono en estos sedimentos.
Principales métodos:
- Análisis del número de células microbianas y las actividades de las exoenzimas hidrolíticas.
- Medición de las tasas de degradación de la glucosa anaeróbica.
- Secuenciación de genes de ARN ribosomal 16S para el análisis de la comunidad microbiana.
Principales resultados:
- Los sapropeles mostraron densidades celulares más altas y una mayor actividad microbiana en comparación con las capas intermedias.
- Las bacterias verdes sin azufre (hasta el 70%) y Crenarchaeota (16%) fueron los grupos microbianos dominantes.
- Evidencia de una rotación lenta pero significativa de glucosa, lo que indica procesos metabólicos en curso.
Conclusiones:
- Las antiguas sapropelas albergan comunidades microbianas metabólicamente activas.
- Las bacterias verdes sin azufre y Crenarchaeota son jugadores clave en la alteración de estos antiguos sedimentos.
- Se están utilizando sustratos de carbono microbiano dentro de sapropeles de hasta 217.000 años de antigüedad.
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