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Reducción del sulfato aeróbico en alfombras microbianas
1National Aeronautics and Space Administration-Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.
Science (New York, N.Y.)
|March 22, 1991
Resumen
Se observó una reducción del sulfato bacteriano en zonas oxigenadas de alfombras hipersalinas, lo que desafía el requisito anaeróbico para este proceso. Los niveles de luz y oxígeno tuvieron un impacto mínimo en las tasas de reducción de sulfatos durante un ciclo de 24 horas.
Área de la Ciencia:
- Microbiología Microbiología.
- La geoquímica es la geoquímica.
- Ciencias ambientales Ciencias ambientales.
Sus antecedentes:
- La reducción disimilatoria de sulfato se considera tradicionalmente un proceso anaeróbico.
- Los entornos hipersalinos albergan comunidades microbianas únicas con vías metabólicas especializadas.
Objetivo del estudio:
- Investigar la ocurrencia y las tasas de reducción de sulfato bacteriano en alfombras microbianas hipersalinas oxigenadas.
- Desafiar el paradigma de que la reducción de sulfatos es exclusivamente anaeróbica.
Principales métodos:
- Mediciones in situ de las tasas de reducción de sulfato bacteriano.
- Monitoreo de los niveles de oxígeno disuelto (O2) dentro de las alfombras hipersalinas.
- Análisis comparativo de la reducción de sulfato en condiciones oxigenadas y anóxicas.
Principales resultados:
- La reducción del sulfato bacteriano se produjo consistentemente dentro de la zona fotosintética bien oxigenada de las alfombras hipersalinas.
- Las tasas de reducción de sulfatos en alfombras oxigenadas durante el día fueron comparables a las tasas en alfombras anóxicas durante la noche.
- Las variaciones en la luz y el O2 durante un ciclo de 24 horas mostraron un efecto mínimo en las tasas de reducción de sulfato.
Conclusiones:
- La reducción disimilatoria de sulfato puede ocurrir en presencia de oxígeno, lo que contradice las opiniones establecidas.
- La reducción de sulfato microbiano en alfombras hipersalinas es menos sensible a las fluctuaciones diurnas de oxígeno de lo que se suponía anteriormente.
- Estos hallazgos tienen implicaciones para la comprensión de los ciclos biogeoquímicos en ambientes extremos.
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