scholarly journals Vertical stratification of microbial communities and isotope geochemistry tie groundwater denitrification to sampling location within a nitrate-contaminated aquifer

Author(s):  
Anirban Chakraborty ◽  
Martin Suchy ◽  
Casey R.J. Hubert ◽  
M. Cathryn Ryan
2011 ◽  
Vol 5 (3) ◽  
pp. 568-568 ◽  
Author(s):  
Pei-Yuan Qian ◽  
Yong Wang ◽  
On On Lee ◽  
Stanley C K Lau ◽  
Jiangke Yang ◽  
...  

2021 ◽  
Vol 277 ◽  
pp. 116765
Author(s):  
Juan F. Mujica-Alarcon ◽  
Steven F. Thornton ◽  
Stephen A. Rolfe

mSystems ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Sean M. Gibbons

ABSTRACT Humanity’s transition from the outdoor environment to the built environment (BE) has reduced our exposure to microbial diversity. The relative importance of factors that contribute to the composition of human-dominated BE microbial communities remains largely unknown. Humanity’s transition from the outdoor environment to the built environment (BE) has reduced our exposure to microbial diversity. The relative importance of factors that contribute to the composition of human-dominated BE microbial communities remains largely unknown. In their article in this issue, Chase and colleagues (J. Chase, J. Fouquier, M. Zare, D. L. Sonderegger, R. Knight, S. T. Kelley, J. Siegel, and J. G. Caporaso, mSystems 1(2):e00022-16, 2016, http://dx.doi.org/10.1128/mSystems.00022-16 ) present an office building study in which they controlled for environmental factors, geography, surface material, sampling location, and human interaction type. They found that surface location and geography were the strongest factors contributing to microbial community structure, while surface material had little effect. Even in the absence of direct human interaction, BE surfaces were composed of 25 to 30% human skin-associated taxa. The authors demonstrate how technical variation across sequencing runs is a major issue, especially in BE work, where the biomass is often low and the potential for PCR contaminants is high. Overall, the authors conclude that BE surfaces are desert-like environments where microbes passively accumulate.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pablo Almela ◽  
Ana Justel ◽  
Antonio Quesada

Ice-free areas represent less than 1% of the Antarctic surface. However, climate change models predict a significant increase in temperatures in the coming decades, triggering a relevant reduction of the ice-covered surface. Microorganisms, adapted to the extreme and fluctuating conditions, are the dominant biota. In this article we analyze the diversity and composition of soil bacterial communities in 52 soil samples on three scales: (i) fine scale, where we compare the differences in the microbial community between top-stratum soils (0–2 cm) and deeper-stratum soils (5–10 cm) at the same sampling point; (ii) medium scale, in which we compare the composition of the microbial community of top-stratum soils from different sampling points within the same sampling location; and (iii) coarse scale, where we compare communities between comparable ecosystems located hundreds of kilometers apart along the Antarctic Peninsula. The results suggest that in ice-free soils exposed for longer periods of time (millennia) microbial communities are significantly different along the soil profiles. However, in recently (decades) deglaciated soils the communities are not different along the soil profile. Furthermore, the microbial communities found in soils at the different sampling locations show a high degree of heterogeneity, with a relevant proportion of unique amplicon sequence variants (ASV) that appeared mainly in low abundance, and only at a single sampling location. The Core90 community, defined as the ASVs shared by 90% of the soils from the 4 sampling locations, was composed of 26 ASVs, representing a small percentage of the total sequences. Nevertheless, the taxonomic composition of the Core80 (ASVs shared by 80% of sampling points per location) of the different sampling locations, was very similar, as they were mostly defined by 20 common taxa, representing up to 75.7% of the sequences of the Core80 communities, suggesting a greater homogeneity of soil bacterial taxa among distant locations.


2020 ◽  
Vol 234 ◽  
pp. 103657
Author(s):  
Eduardo J. Aguilar-Rangel ◽  
Blanca L. Prado ◽  
María Soledad Vásquez-Murrieta ◽  
Paulina Estrada-de los Santos ◽  
Christina Siebe ◽  
...  

1999 ◽  
Vol 65 (7) ◽  
pp. 3056-3063 ◽  
Author(s):  
Juliette N. Rooney-Varga ◽  
Robert T. Anderson ◽  
Jocelyn L. Fraga ◽  
David Ringelberg ◽  
Derek R. Lovley

ABSTRACT Microbial community composition associated with benzene oxidation under in situ Fe(III)-reducing conditions in a petroleum-contaminated aquifer located in Bemidji, Minn., was investigated. Community structure associated with benzene degradation was compared to sediment communities that did not anaerobically oxidize benzene which were obtained from two adjacent Fe(III)-reducing sites and from methanogenic and uncontaminated zones. Denaturing gradient gel electrophoresis of 16S rDNA sequences amplified with bacterial orGeobacteraceae-specific primers indicated significant differences in the composition of the microbial communities at the different sites. Most notable was a selective enrichment of microorganisms in the Geobacter cluster seen in the benzene-degrading sediments. This finding was in accordance with phospholipid fatty acid analysis and most-probable-number–PCR enumeration, which indicated that members of the familyGeobacteraceae were more numerous in these sediments. A benzene-oxidizing Fe(III)-reducing enrichment culture was established from benzene-degrading sediments and contained an organism closely related to the uncultivated Geobacter spp. This genus contains the only known organisms that can oxidize aromatic compounds with the reduction of Fe(III). Sequences closely related to the Fe(III) reducer Geothrix fermentans and the aerobe Variovorax paradoxus were also amplified from the benzene-degrading enrichment and were present in the benzene-degrading sediments. However, neither G. fermentans nor V. paradoxusis known to oxidize aromatic compounds with the reduction of Fe(III), and there was no apparent enrichment of these organisms in the benzene-degrading sediments. These results suggest thatGeobacter spp. play an important role in the anaerobic oxidation of benzene in the Bemidji aquifer and that molecular community analysis may be a powerful tool for predicting a site’s capacity for anaerobic benzene degradation.


2009 ◽  
Vol 11 (10) ◽  
pp. 2611-2626 ◽  
Author(s):  
Joy D. Van Nostrand ◽  
Wei-Min Wu ◽  
Liyou Wu ◽  
Ye Deng ◽  
Jack Carley ◽  
...  

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