Microbial Degradation Rates of Natural Bitumen
| Autor: | John Maximilian Köhne, Daniel Köster, Michelle Kulbatzki, Lisa Voskuhl, Sadjad Mohammadian, S. Haque, Arne Meier, Rainer U. Meckenstock, Mark Pannekens, Ali Akbari |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
isotope dilution
Microorganism Chemie 010501 environmental sciences anaerobic biodegradation 01 natural sciences Mineralization (biology) Article micro habitats oil reservoirs water droplets Environmental Chemistry Microbial biodegradation petroleum mineralization 0105 earth and related environmental sciences Bacteria Brackish water General Chemistry Biodegradation Hydrocarbons 6. Clean water asphalt Biodegradation Environmental Petroleum Microbial population biology Asphalt Environmental chemistry biofilm formation Environmental science Microcosm |
| Zdroj: | Environmental Science & Technology |
| Popis: | Microorganisms are present in nearly every oil or bitumen sample originating from temperate reservoirs. Nevertheless, it is very difficult to obtain reliable estimates about microbial processes taking place in deep reservoirs, since metabolic rates are rather low and differ strongly during artificially cultivation. Here, we demonstrate the importance and impact of microorganisms entrapped in microscale water droplets for the overall biodegradation process in bitumen. To this end, we measured degradation rates of heavily biodegraded bitumen from the Pitch Lake (Trinidad and Tobago) using the novel technique of reverse stable isotope labeling, allowing precise measurements of comparatively low mineralization rates in the ng range in microcosms under close to natural conditions. Freshly taken bitumen samples were overlain with artificial brackish water and incubated for 945 days. Additionally, three-dimensional distribution of water droplets in bitumen was studied with computed tomography, revealing a water bitumen interface of 1134 cm2 per liter bitumen, resulting in an average mineralization rate of 9.4–38.6 mmol CO2 per liter bitumen and year. Furthermore, a stable and biofilm-forming microbial community established on the bitumen itself, mainly composed of fermenting and sulfate-reducing bacteria. Our results suggest that small water inclusions inside the bitumen substantially increase the bitumen–water interface and might have a major impact on the overall oil degradation process. Tiny water droplets in natural bitumen reservoirs substantially increase the bitumen−water interface and potentially impact the entire biodegradation process. |
| Databáze: | OpenAIRE |
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