Physicochemical Characterization of Acidiphilium sp. Biofilms

Authors

  • Dr. Moustafa Malki,

    1. Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
    2. Microbiologia aplicada Centro de Biología Molecular Severo Ochoa, UAM-CSIC, Universidad Autónoma de Madrid, 28049 Madrid (Spain)
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  • Dr. Santiago Casado,

    1. Nanoscience, Instituto Madrileño de estudios Avanzados, Avda. Fco. Tomás y Valiente, 7, 28049 Madrid (Spain)
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  • Dr. María Francisca López,

    1. Surfaces and Coatings, Instituto de Ciencia de Materiales de Madrid, CSIC, 3 Sor Juana Inés de la Cruz, 28049 Madrid (Spain)
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  • Dr. Renaud Caillard,

    1. Surfaces and Coatings, Instituto de Ciencia de Materiales de Madrid, CSIC, 3 Sor Juana Inés de la Cruz, 28049 Madrid (Spain)
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  • Dr. F. Javier Palomares,

    1. Surfaces and Coatings, Instituto de Ciencia de Materiales de Madrid, CSIC, 3 Sor Juana Inés de la Cruz, 28049 Madrid (Spain)
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  • Dr. José A. Martín Gago,

    1. Surfaces and Coatings, Instituto de Ciencia de Materiales de Madrid, CSIC, 3 Sor Juana Inés de la Cruz, 28049 Madrid (Spain)
    2. Centro de Astrobiología, INTA-CSIC, 28850 Torrejón de Ardoz (Spain)
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  • Dr. Cristina Vaz-Domínguez,

    1. Electroquímica, Instituto de Química-Física Rocasolano, CSIC, 119 Serrano, 28006 Madrid (Spain)
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  • Dr. Angel Cuesta,

    1. Electroquímica, Instituto de Química-Física Rocasolano, CSIC, 119 Serrano, 28006 Madrid (Spain)
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  • Prof. Ricardo Amils,

    1. Microbiologia aplicada Centro de Biología Molecular Severo Ochoa, UAM-CSIC, Universidad Autónoma de Madrid, 28049 Madrid (Spain)
    2. Centro de Astrobiología, INTA-CSIC, 28850 Torrejón de Ardoz (Spain)
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  • Prof. Víctor M. Fernández,

    1. Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
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  • Dr. Marisela Velez,

    1. Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
    2. Nanoscience, Instituto Madrileño de estudios Avanzados, Avda. Fco. Tomás y Valiente, 7, 28049 Madrid (Spain)
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  • Dr. Antonio L. De Lacey,

    Corresponding author
    1. Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
    • Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
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  • Dr. David Olea

    Corresponding author
    1. Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
    • Bioctalysis, Instituto de Catálisis y Petroleoquímica, CSIC, 2 Marie Curie, 28049 Madrid (Spain), Fax: (+34) 91 585 4760)
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Abstract

The biofilm formation of a strain of the extremophile bacterium Acidiphilium sp., capable of donating electrons directly to electrodes, was studied by different surface characterization techniques. We develop a method that allows the simultaneous study of bacterial biofilms by means of fluorescence microscopy and atomic force microscopy (AFM), in which transparent graphitic flakes deposited on a glass substrate are used as a support for the biofilm. The majority of the cells present on the surface were viable, and the growth of the biofilms over time showed a critical increase of the extracellular polymeric substances (EPS) as well as the formation of nanosized particles inside the biofilm. Also, the presence of Fe in Acidiphilium biofilms was determined by X-ray photoelectron spectroscopy (XPS), whereas surface-enhanced infrared absorption spectroscopy indicated the presence of redox-active proteins.

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