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Title: Developing methanogenic microbial consortia from diverse coal sources and environments

Abstract

Biogenic gas production is a promising alternative or supplement to conventional methane extraction from coalbeds. Adsorbed and free gas, generated over geologic time, can be supplemented with biogenic gas during short-term engineering operations. There are two generic protocols for doing this. The first is to contact the coal with nutrients to support native bacterial development. The second approach is to inject appropriately cultured ex-situ consortia into subsurface coal accumulations. Research has mainly focused on the former: in-situ stimulation of native microbial communities with added nutrients. Relatively few studies have been conducted on the strategies for enriching ex-situ microbial populations under initial atmospheric exposure for subsequent injection into coal seams to stimulate biodegradation, and methanogenesis. In order to evaluate the feasibility of ex-situ cultivation, natural microbial populations were collected from various hydrocarbon-rich environments and locations characterized by natural methanogenesis. Different rank coals (i.e., lignite, sub-bituminous, bituminous), complex hydrocarbon sources (i.e., oil shale, waxy crude), hydrocarbon seeps, and natural biogenic environments were incorporated in the sampling. Three levels of screening (down-selection to high grade the most productive consortia) allowed selection of microbial populations, favorable nutrient amendments, sources of the microbial community, and quantification of methane produced from various coal types. Incubation periodsmore » of up to twenty-four weeks were evaluated at 23 °C. Headspace concentrations of CH 4 and CO 2 were analyzed by gas chromatography. After a two-week incubation period of the most promising microbes, generated headspace gas concentrations reached 873,400 ppm (154 sft 3/ton or 4.8 scm 3/g) for methane and 176,370 ppm (31 sft 3/ton or 0.9 scm 3/g) for carbon dioxide. Rudimentary statistical assessments – variance analysis (ANOVA) of a single factor - were used to identify trends and levels of significance or impact of the consortia enrichment. We then demonstrated that microbial communities from coal and lake sediments can be enriched and adapted to effectively generate methane under initial atmospheric exposure. The development and enrichment of these methanogenic consortia is described.« less

Authors:
 [1];  [1];  [2];  [3];  [4];  [4]
  1. Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemical Engineering
  2. Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemical Engineering; Energy and Geoscience Inst., Salt Lake City, UT (United States)
  3. Inotec Inc., Salt Lake City, UT (United States)
  4. Univ. of Utah, Salt Lake City, UT (United States). Dept. of Biology
Publication Date:
Research Org.:
Univ. of Utah, Salt Lake City, UT (United States)
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1415143
Grant/Contract Number:
FE0024088
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Natural Gas Science and Engineering
Additional Journal Information:
Journal Volume: 46; Journal Issue: C; Journal ID: ISSN 1875-5100
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; gasification; Microbial consortia; Methanogenesis; CBM; Methane; Carbon dioxide

Citation Formats

Fuertez, John, Boakye, Richard, McLennan, John, Adams, D. Jack, Sparks, Taylor D., and Gottschalk, Austin. Developing methanogenic microbial consortia from diverse coal sources and environments. United States: N. p., 2017. Web. doi:10.1016/j.jngse.2017.07.028.
Fuertez, John, Boakye, Richard, McLennan, John, Adams, D. Jack, Sparks, Taylor D., & Gottschalk, Austin. Developing methanogenic microbial consortia from diverse coal sources and environments. United States. doi:10.1016/j.jngse.2017.07.028.
Fuertez, John, Boakye, Richard, McLennan, John, Adams, D. Jack, Sparks, Taylor D., and Gottschalk, Austin. 2017. "Developing methanogenic microbial consortia from diverse coal sources and environments". United States. doi:10.1016/j.jngse.2017.07.028.
@article{osti_1415143,
title = {Developing methanogenic microbial consortia from diverse coal sources and environments},
author = {Fuertez, John and Boakye, Richard and McLennan, John and Adams, D. Jack and Sparks, Taylor D. and Gottschalk, Austin},
abstractNote = {Biogenic gas production is a promising alternative or supplement to conventional methane extraction from coalbeds. Adsorbed and free gas, generated over geologic time, can be supplemented with biogenic gas during short-term engineering operations. There are two generic protocols for doing this. The first is to contact the coal with nutrients to support native bacterial development. The second approach is to inject appropriately cultured ex-situ consortia into subsurface coal accumulations. Research has mainly focused on the former: in-situ stimulation of native microbial communities with added nutrients. Relatively few studies have been conducted on the strategies for enriching ex-situ microbial populations under initial atmospheric exposure for subsequent injection into coal seams to stimulate biodegradation, and methanogenesis. In order to evaluate the feasibility of ex-situ cultivation, natural microbial populations were collected from various hydrocarbon-rich environments and locations characterized by natural methanogenesis. Different rank coals (i.e., lignite, sub-bituminous, bituminous), complex hydrocarbon sources (i.e., oil shale, waxy crude), hydrocarbon seeps, and natural biogenic environments were incorporated in the sampling. Three levels of screening (down-selection to high grade the most productive consortia) allowed selection of microbial populations, favorable nutrient amendments, sources of the microbial community, and quantification of methane produced from various coal types. Incubation periods of up to twenty-four weeks were evaluated at 23 °C. Headspace concentrations of CH4 and CO2 were analyzed by gas chromatography. After a two-week incubation period of the most promising microbes, generated headspace gas concentrations reached 873,400 ppm (154 sft3/ton or 4.8 scm3/g) for methane and 176,370 ppm (31 sft3/ton or 0.9 scm3/g) for carbon dioxide. Rudimentary statistical assessments – variance analysis (ANOVA) of a single factor - were used to identify trends and levels of significance or impact of the consortia enrichment. We then demonstrated that microbial communities from coal and lake sediments can be enriched and adapted to effectively generate methane under initial atmospheric exposure. The development and enrichment of these methanogenic consortia is described.},
doi = {10.1016/j.jngse.2017.07.028},
journal = {Journal of Natural Gas Science and Engineering},
number = C,
volume = 46,
place = {United States},
year = 2017,
month = 8
}

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  • Microbial souring (H[sub 2]S production) in porous media was investigated in an anaerobic upflow porous media reactor at 60 C using microbial consortia obtained from oil reservoirs. Multiple carbon sources (formate, acetate, propionate, iso and n-butyrates) found in reservoir waters as well as sulfate as the electron acceptor were used. Kinetics and rates of souring in the reactor system were analyzed. Higher volumetric substrate consumption rates (organic acids and sulfate) and a higher volumetric H[sub 2]S production rate were found at the front part of the reactor column after H[sub 2]S production had stabilized. Concentration gradients for the substrates (organicmore » acids and sulfate) and H[sub 2]S were generated along the column. Biomass accumulation throughout the entire column was observed. The average specific sulfate reduction rate (H[sub 2]S production rate) in the present reactor after H[sub 2]S production had stabilized was calculated to be 11.62 [+-] 2.22 mg sulfate-S/day g biomass.« less
  • Knowledge of the diversity and ecological function of the microbial consortia of James River in Virginia, USA, is essential to developing a more complete understanding of the ecology of this model river system. Metagenomic analysis of James River's planktonic microbial community was performed for the first time using an unamplified genomic library and a 16S rDNA amplicon library prepared and sequenced by Ion PGM and MiSeq, respectively. From the 0.46-Gb WGS library (GenBank:SRR1146621; MG-RAST:4532156.3), 4 x 10 6 reads revealed >3 x 10 6 genes, 240 families of prokaryotes, and 155 families of eukaryotes. From the 0.68-Gb 16S library (GenBank:SRR2124995;more » MG-RAST:4631271.3; EMB:2184), 4 x 10 6 reads revealed 259 families of eubacteria. Results of the WGS and 16S analyses were highly consistent and indicated that more than half of the bacterial sequences were Proteobacteria, predominantly Comamonadaceae. The most numerous genera in this group were Acidovorax (including iron oxidizers, nitrotolulene degraders, and plant pathogens), which accounted for 10 % of assigned bacterial reads. Polaromonas were another 6 % of all bacterial reads, with many assignments to groups capable of degrading polycyclic aromatic hydrocarbons. Albidiferax (iron reducers) and Variovorax (biodegraders of a variety of natural biogenic compounds as well as anthropogenic contaminants such as polycyclic aromatic hydrocarbons and endocrine disruptors) each accounted for an additional 3% of bacterial reads. Comparison of these data to other publically-available aquatic metagenomes revealed that this stretch of James River is highly similar to the upper Mississippi River, and that these river systems are more similar to aquaculture and sludge ecosystems than they are to lakes or to a pristine section of the upper Amazon River. Altogether, these analyses exposed previously unknown aspects of microbial biodiversity, documented the ecological responses of microbes to urban effects, and revealed the noteworthy presence of 22 human-pathogenic bacterial genera (e.g., Enterobacteriaceae, pathogenic Pseudomonadaceae, and ‘Vibrionales') and 6 pathogenic eukaryotic genera (e.g., Trypanosomatidae and Vahlkampfiidae). This information about pathogen diversity may be used to promote human epidemiological studies, enhance existing water quality monitoring efforts, and increase awareness of the possible health risks associated with recreational use of James River.« less
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