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GFAJ-1 es un organismo resistente al arseniato y dependiente del fosfato
Tobias J Erb1, Patrick Kiefer, Bodo Hattendorf
1Institute of Microbiology, Eidgenössische Technische Hochschule Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland. toerb@ethz.ch
Science (New York, N.Y.)
|July 10, 2012
Resumen
La bacteria GFAJ-1 puede crecer con bajo fosfato y alto arseniato, pero requiere fosfato para sobrevivir. Este estudio confirma que GFAJ-1 es resistente al arsenato pero dependiente del fosfato, no una forma de vida basada en el arsénico.
Área de la Ciencia:
- Microbiología Microbiología.
- La bioquímica es la bioquímica.
- Astrobiología Astrobiología.
Sus antecedentes:
- Anteriormente se sugirió que la bacteria GFAJ-1 utilizara arsénico en lugar de fósforo para su crecimiento.
- Esta hipótesis proponía una nueva forma de vida, desafiando los principios bioquímicos fundamentales.
Objetivo del estudio:
- Para investigar los requisitos de crecimiento y la composición bioquímica de GFAJ-1 bajo diferentes condiciones de fosfato y arseniato.
- Para determinar definitivamente si GFAJ-1 puede sustituir el arsénico por el fósforo.
Principales métodos:
- Cultivo de GFAJ-1 en medios con concentraciones controladas de fosfato y arseniato.
- Espectrometría de masas de alta resolución para analizar metabolitos celulares y ácidos nucleicos.
- Espectrometría de masa de plasma acoplada por inducción para cuantificar el contenido de arsénico y fósforo.
Principales resultados:
- GFAJ-1 crece en bajos niveles de fosfato (1,7 μM) con altos niveles de arsenato (40 mM), pero no en medios empobrecidos de fósforo.
- Los metabolitos fosforilados y los ácidos nucleicos fueron predominantes.
- Se encontró que los compuestos arsenilados detectados se forman abióticamente; el arsénico no se detectó en los ácidos nucleicos.
Conclusiones:
- GFAJ-1 es una bacteria resistente al arseniato.
- GFAJ-1 sigue dependiendo del fosfato para su crecimiento y supervivencia.
- La bacteria no sustituye el arsénico por el fósforo en su bioquímica central.
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