• Open Access

First evidence of mineralization of petroleum asphaltenes by a strain of Neosartorya fischeri

Authors

  • Cristina Uribe-Alvarez,

    1. Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
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  • Marcela Ayala,

    1. Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
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  • Lucia Perezgasga,

    1. Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
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  • Leopoldo Naranjo,

    1. Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas 1080, Venezuela
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  • Héctor Urbina,

    1. Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas 1080, Venezuela
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  • Rafael Vazquez-Duhalt

    Corresponding author
    1. Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
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E-mail vazqduh@ibt.unam.mx; Tel. (+52) 7773291655; Fax (+52) 7773172388.

Summary

A fungal strain isolated from a microbial consortium growing in a natural asphalt lake is able to grow in purified asphaltenes as the only source of carbon and energy. The asphaltenes were rigorously purified in order to avoid contamination from other petroleum fractions. In addition, most of petroporphyrins were removed. The 18S rRNA and β-tubulin genomic sequences, as well as some morphologic characteristics, indicate that the isolate is Neosartorya fischeri. After 11 weeks of growth, the fungus is able to metabolize 15.5% of the asphaltenic carbon, including 13.2% transformed to CO2. In a medium containing asphaltenes as the sole source of carbon and energy, the fungal isolate produces extracellular laccase activity, which is not detected when the fungus grow in a rich medium. The results obtained in this work clearly demonstrate that there are microorganisms able to metabolize and mineralize asphaltenes, which is considered the most recalcitrant petroleum fraction.

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