Modified Lipid Extraction Methods for Deep Subsurface Shale
Growing interest in the utilization of black shales for hydrocarbon development and environmental applications has spurred investigations of microbial functional diversity in the deep subsurface shale ecosystem. Lipid biomarker analyses including phospholipid fatty acids (PLFAs) and diglyceride fatt...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-07-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2017.01408/full |
| _version_ | 1811283095517659136 |
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| author | Rawlings N. Akondi Ryan V. Trexler Susan M. Pfiffner Paula J. Mouser Shikha Sharma |
| author_facet | Rawlings N. Akondi Ryan V. Trexler Susan M. Pfiffner Paula J. Mouser Shikha Sharma |
| author_sort | Rawlings N. Akondi |
| collection | DOAJ |
| description | Growing interest in the utilization of black shales for hydrocarbon development and environmental applications has spurred investigations of microbial functional diversity in the deep subsurface shale ecosystem. Lipid biomarker analyses including phospholipid fatty acids (PLFAs) and diglyceride fatty acids (DGFAs) represent sensitive tools for estimating biomass and characterizing the diversity of microbial communities. However, complex shale matrix properties create immense challenges for microbial lipid extraction procedures. Here, we test three different lipid extraction methods: modified Bligh and Dyer (mBD), Folch (FOL), and microwave assisted extraction (MAE), to examine their ability in the recovery and reproducibility of lipid biomarkers in deeply buried shales. The lipid biomarkers were analyzed as fatty acid methyl esters (FAMEs) with the GC-MS, and the average PL-FAME yield ranged from 67 to 400 pmol/g, while the average DG-FAME yield ranged from 600 to 3,000 pmol/g. The biomarker yields in the intact phospholipid Bligh and Dyer treatment (mBD + Phos + POPC), the Folch, the Bligh and Dyer citrate buffer (mBD-Cit), and the MAE treatments were all relatively higher and statistically similar compared to the other extraction treatments for both PLFAs and DGFAs. The biomarker yields were however highly variable within replicates for most extraction treatments, although the mBD + Phos + POPC treatment had relatively better reproducibility in the consistent fatty acid profiles. This variability across treatments which is associated with the highly complex nature of deeply buried shale matrix, further necessitates customized methodological developments for the improvement of lipid biomarker recovery. |
| first_indexed | 2024-04-13T02:05:29Z |
| format | Article |
| id | doaj.art-da359d7802b94697b78ba3bfd782d86a |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-13T02:05:29Z |
| publishDate | 2017-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-da359d7802b94697b78ba3bfd782d86a2022-12-22T03:07:29ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2017-07-01810.3389/fmicb.2017.01408263289Modified Lipid Extraction Methods for Deep Subsurface ShaleRawlings N. Akondi0Ryan V. Trexler1Susan M. Pfiffner2Paula J. Mouser3Shikha Sharma4Department of Geology and Geography, West Virginia UniversityMorgantown, WV, United StatesCivil, Environmental and Geodetic Engineering, The Ohio State UniversityColumbus, OH, United StatesCenter for Environmental Biotechnology, University of TennesseeKnoxville, TN, United StatesCivil, Environmental and Geodetic Engineering, The Ohio State UniversityColumbus, OH, United StatesDepartment of Geology and Geography, West Virginia UniversityMorgantown, WV, United StatesGrowing interest in the utilization of black shales for hydrocarbon development and environmental applications has spurred investigations of microbial functional diversity in the deep subsurface shale ecosystem. Lipid biomarker analyses including phospholipid fatty acids (PLFAs) and diglyceride fatty acids (DGFAs) represent sensitive tools for estimating biomass and characterizing the diversity of microbial communities. However, complex shale matrix properties create immense challenges for microbial lipid extraction procedures. Here, we test three different lipid extraction methods: modified Bligh and Dyer (mBD), Folch (FOL), and microwave assisted extraction (MAE), to examine their ability in the recovery and reproducibility of lipid biomarkers in deeply buried shales. The lipid biomarkers were analyzed as fatty acid methyl esters (FAMEs) with the GC-MS, and the average PL-FAME yield ranged from 67 to 400 pmol/g, while the average DG-FAME yield ranged from 600 to 3,000 pmol/g. The biomarker yields in the intact phospholipid Bligh and Dyer treatment (mBD + Phos + POPC), the Folch, the Bligh and Dyer citrate buffer (mBD-Cit), and the MAE treatments were all relatively higher and statistically similar compared to the other extraction treatments for both PLFAs and DGFAs. The biomarker yields were however highly variable within replicates for most extraction treatments, although the mBD + Phos + POPC treatment had relatively better reproducibility in the consistent fatty acid profiles. This variability across treatments which is associated with the highly complex nature of deeply buried shale matrix, further necessitates customized methodological developments for the improvement of lipid biomarker recovery.http://journal.frontiersin.org/article/10.3389/fmicb.2017.01408/fullPLFADGFAmicrobial biomassdeep subsurfaceshale ecosystem |
| spellingShingle | Rawlings N. Akondi Ryan V. Trexler Susan M. Pfiffner Paula J. Mouser Shikha Sharma Modified Lipid Extraction Methods for Deep Subsurface Shale Frontiers in Microbiology PLFA DGFA microbial biomass deep subsurface shale ecosystem |
| title | Modified Lipid Extraction Methods for Deep Subsurface Shale |
| title_full | Modified Lipid Extraction Methods for Deep Subsurface Shale |
| title_fullStr | Modified Lipid Extraction Methods for Deep Subsurface Shale |
| title_full_unstemmed | Modified Lipid Extraction Methods for Deep Subsurface Shale |
| title_short | Modified Lipid Extraction Methods for Deep Subsurface Shale |
| title_sort | modified lipid extraction methods for deep subsurface shale |
| topic | PLFA DGFA microbial biomass deep subsurface shale ecosystem |
| url | http://journal.frontiersin.org/article/10.3389/fmicb.2017.01408/full |
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