RESUMO

Anaerobic microbial degradation of hydrocarbons, typically occurring at the oil-water transition zone, influences the quality of oil reservoirs. In Pitch Lake, Trinidad and Tobago--the world's largest asphalt lake--we found that microorganisms are metabolically active in minuscule water droplets (1 to 3 microliters) entrapped in oil. Pyrotag sequencing of individual droplet microbiomes revealed complex methanogenic microbial communities actively degrading the oil into a diverse range of metabolites, as shown by nuclear magnetic resonance and Fourier transform ion cyclotron resonance mass spectrometry. High salinity and water-stable isotopes of the droplets indicate a deep subsurface origin. The 13.5% water content and the large surface area of the droplets represent an underestimated potential for biodegradation of oil away from the oil-water transition zone.

Assuntos

Archaea/metabolismo , Bactérias/metabolismo , Lagos/microbiologia , Microbiota/genética , Petróleo/metabolismo , Microbiologia da Água , Anaerobiose , Archaea/genética , Archaea/isolamento & purificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Análise de Fourier , Espectroscopia de Ressonância Magnética , Trinidad e Tobago