1. In situ transformation of ethoxylate and glycol surfactants by shale-colonizing microorganisms during hydraulic fracturing
- Author
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Molly C. McLaughlin, Thomas O. Metz, Paula J. Mouser, David R. Cole, Gordon J. Getzinger, Andrea J. Hanson, Chengdong Xu, Morgan V. Evans, David W. Hoyt, P. Lee Ferguson, Michael J. Wilkins, Jens Blotevogel, Mary S. Lipton, Thomas H. Darrah, Jenna L. Luek, Susan A. Welch, Carrie D. Nicora, and Samuel O. Purvine more...
- Subjects
Proteomics ,Microorganism ,Natural Gas ,Wastewater ,Biology ,Bacterial growth ,Microbiology ,Article ,Glycols ,Surface-Active Agents ,03 medical and health sciences ,chemistry.chemical_compound ,Hydraulic fracturing ,Oil and Gas Fields ,Hydraulic Fracking ,Ecology, Evolution, Behavior and Systematics ,Ohio ,030304 developmental biology ,Minerals ,0303 health sciences ,Bacteria ,030306 microbiology ,Microbiota ,Biodegradation ,Biodegradation, Environmental ,chemistry ,Microbial population biology ,Environmental chemistry ,Xenobiotic ,Oil shale - Abstract
In the last decade, extensive application of hydraulic fracturing technologies to unconventional low-permeability hydrocarbon-rich formations has significantly increased natural-gas production in the United States and abroad. The injection of surface-sourced fluids to generate fractures in the deep subsurface introduces microbial cells and substrates to low-permeability rock. A subset of injected organic additives has been investigated for their ability to support biological growth in shale microbial community members; however, to date, little is known on how complex xenobiotic organic compounds undergo biotransformations in this deep rock ecosystem. Here, high-resolution chemical, metagenomic, and proteomic analyses reveal that widely-used surfactants are degraded by the shale-associated taxa Halanaerobium, both in situ and under laboratory conditions. These halotolerant bacteria exhibit surfactant substrate specificities, preferring polymeric propoxylated glycols (PPGs) and longer alkyl polyethoxylates (AEOs) over polyethylene glycols (PEGs) and shorter AEOs. Enzymatic transformation occurs through repeated terminal-end polyglycol chain shortening during co-metabolic growth through the methylglyoxal bypass. This work provides the first evidence that shale microorganisms can transform xenobiotic surfactants in fracture fluid formulations, potentially affecting the efficiency of hydrocarbon recovery, and demonstrating an important association between injected substrates and microbial growth in an engineered subsurface ecosystem. more...
- Published
- 2019
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