scholarly journals Comparative metagenomics of coalbed methane microbial communities reveals biogenic methane potential in the Appalachian Basin

2018 ◽  
Author(s):  
Daniel E. Ross ◽  
Daniel Lipus ◽  
Kelvin B. Gregory ◽  
Djuna Gulliver
Keyword(s):  
Microbial Communities ◽  
Methane Production ◽  
Coalbed Methane ◽  
Large Fraction ◽  
Appalachian Basin ◽  
Well Performance ◽  
Biogenic Methane ◽  
Comparative Metagenomics ◽  
Functionally Diverse ◽  
High Degree

Natural gas is a major source of global energy, and a large fraction is generated in subsurface coalbed deposits. Microbial communities within coalbed deposits impact methane production, and as a result contribute to global carbon cycling. The process of biogenic coal-to-methane conversion is not well understood. Here we demonstrate the first read- and assembly-based metagenome profiling of coal-associated formation waters, resulting in the recovery of over 40 metagenome-assembled genomes (MAGs) from eight individual coalbed methane wells in the Appalachian Basin. The majority of samples contained hydrogenotrophic methanogens, which were present in higher relative abundances than was previously reported for other coalbed basins. The abundance of Archaea and salinity were positively correlated, suggesting that salinity may be a controlling factor for biogenic coalbed methane. Low-abundance coalbed microbial populations were functionally diverse, while the most dominant organisms exhibit a high degree of genomic and functional similarities. Basin-specific pan-metagenome clustering suggests lower abundant and diverse bacterial communities are shaped by local basin parameters. Our analyses show Appalachian Basin coalbed microbial communities encode for the potential to convert coal into methane, which may be used as an indicator of potential biogenic methane production for future well performance and increased well longevity.

IDENTIFYING THE SOURCE, PATHWAYS, AND RATES OF ENHANCED MICROBIAL COALBED METHANE PRODUCTION

2016 ◽  
Author(s):  
Katherine J. Davis ◽  
◽  
Robin Gerlach ◽  
H.D. Schweitzer ◽  
Al Cunningham ◽  
...  
Keyword(s):  
Methane Production ◽  
Coalbed Methane ◽  
Coalbed Methane Production

scholarly journals Evaluation of acidogenesis products’ effect on biogas production performed with metagenomics and isotopic approaches

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Anna Detman ◽  
Michał Bucha ◽  
Laura Treu ◽  
Aleksandra Chojnacka ◽  
Łukasz Pleśniak ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Methane Production ◽  
Bacterial Species ◽  
Stable Carbon Isotope ◽  
Anaerobic Sludge ◽  
Methane Formation ◽  
Microbial Composition ◽  
Fermentation Products ◽  
Core Microbiome ◽  
Specific Species

Abstract Background During the acetogenic step of anaerobic digestion, the products of acidogenesis are oxidized to substrates for methanogenesis: hydrogen, carbon dioxide and acetate. Acetogenesis and methanogenesis are highly interconnected processes due to the syntrophic associations between acetogenic bacteria and hydrogenotrophic methanogens, allowing the whole process to become thermodynamically favorable. The aim of this study is to determine the influence of the dominant acidic products on the metabolic pathways of methane formation and to find a core microbiome and substrate-specific species in a mixed biogas-producing system. Results Four methane-producing microbial communities were fed with artificial media having one dominant component, respectively, lactate, butyrate, propionate and acetate, for 896 days in 3.5-L Up-flow Anaerobic Sludge Blanket (UASB) bioreactors. All the microbial communities showed moderately different methane production and utilization of the substrates. Analyses of stable carbon isotope composition of the fermentation gas and the substrates showed differences in average values of δ13C(CH4) and δ13C(CO2) revealing that acetate and lactate strongly favored the acetotrophic pathway, while butyrate and propionate favored the hydrogenotrophic pathway of methane formation. Genome-centric metagenomic analysis recovered 234 Metagenome Assembled Genomes (MAGs), including 31 archaeal and 203 bacterial species, mostly unknown and uncultivable. MAGs accounted for 54%–67% of the entire microbial community (depending on the bioreactor) and evidenced that the microbiome is extremely complex in terms of the number of species. The core microbiome was composed of Methanothrix soehngenii (the most abundant), Methanoculleus sp., unknown Bacteroidales and Spirochaetaceae. Relative abundance analysis of all the samples revealed microbes having substrate preferences. Substrate-specific species were mostly unknown and not predominant in the microbial communities. Conclusions In this experimental system, the dominant fermentation products subjected to methanogenesis moderately modified the final effect of bioreactor performance. At the molecular level, a different contribution of acetotrophic and hydrogenotrophic pathways for methane production, a very high level of new species recovered, and a moderate variability in microbial composition depending on substrate availability were evidenced. Propionate was not a factor ceasing methane production. All these findings are relevant because lactate, acetate, propionate and butyrate are the universal products of acidogenesis, regardless of feedstock.

scholarly journals Serial Analysis of the Gut and Respiratory Microbiome in Cystic Fibrosis in Infancy: Interaction between Intestinal and Respiratory Tracts and Impact of Nutritional Exposures

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
J. C. Madan ◽  
D. C. Koestler ◽  
B. A. Stanton ◽  
L. Davidson ◽  
L. A. Moulton ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Microbial Communities ◽  
Effective Means ◽  
Significant Proportion ◽  
Gut Colonization ◽  
Pulmonary Damage ◽  
Chronic Colonization ◽  
High Degree ◽  
Over Time

ABSTRACT Pulmonary damage caused by chronic colonization of the cystic fibrosis (CF) lung by microbial communities is the proximal cause of respiratory failure. While there has been an effort to document the microbiome of the CF lung in pediatric and adult patients, little is known regarding the developing microflora in infants. We examined the respiratory and intestinal microbiota development in infants with CF from birth to 21 months. Distinct genera dominated in the gut compared to those in the respiratory tract, yet some bacteria overlapped, demonstrating a core microbiota dominated by Veillonella and Streptococcus. Bacterial diversity increased significantly over time, with evidence of more rapidly acquired diversity in the respiratory tract. There was a high degree of concordance between the bacteria that were increasing or decreasing over time in both compartments; in particular, a significant proportion (14/16 genera) increasing in the gut were also increasing in the respiratory tract. For 7 genera, gut colonization presages their appearance in the respiratory tract. Clustering analysis of respiratory samples indicated profiles of bacteria associated with breast-feeding, and for gut samples, introduction of solid foods even after adjustment for the time at which the sample was collected. Furthermore, changes in diet also result in altered respiratory microflora, suggesting a link between nutrition and development of microbial communities in the respiratory tract. Our findings suggest that nutritional factors and gut colonization patterns are determinants of the microbial development of respiratory tract microbiota in infants with CF and present opportunities for early intervention in CF with altered dietary or probiotic strategies. IMPORTANCE While efforts have been focused on assessing the microbiome of pediatric and adult cystic fibrosis (CF) patients to understand how chronic colonization by these microbes contributes to pulmonary damage, little is known regarding the earliest development of respiratory and gut microflora in infants with CF. Our findings suggest that colonization of the respiratory tract by microbes is presaged by colonization of the gut and demonstrated a role of nutrition in development of the respiratory microflora. Thus, targeted dietary or probiotic strategies may be an effective means to change the course of the colonization of the CF lung and thereby improve patient outcomes.

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