Nitrate alleviate dissimilatory iron reduction and arsenic mobilization by driving microbial community structure change

ABSTRACTThe development of unconventional oil and gas (UOG) resources results in the production of large volumes of wastewater containing a complex mixture of hydraulic fracturing chemical additives and components from the formation. The release of these wastewaters into the environment poses potential risks that are poorly understood. Microbial communities in stream sediments form the base of the food chain and may serve as sentinels for changes in stream health. Iron-reducing organisms have been shown to play a role in the biodegradation of a wide range of organic compounds, and so to evaluate their response to UOG wastewater, we enriched anaerobic microbial communities from sediments collected upstream (background) and downstream (impacted) of an UOG wastewater injection disposal facility in the presence of hydraulic fracturing fluid (HFF) additives: guar gum, ethylene glycol, and two biocides, 2,2-dibromo-3-nitrilopropionamide (DBNPA) and bronopol (C3H6BrNO4). Iron reduction was significantly inhibited early in the incubations with the addition of biocides, whereas amendment with guar gum and ethylene glycol stimulated iron reduction relative to levels in the unamended controls. Changes in the microbial community structure were observed across all treatments, indicating the potential for even small amounts of UOG wastewater components to influence natural microbial processes. The microbial community structure differed between enrichments with background and impacted sediments, suggesting that impacted sediments may have been preconditioned by exposure to wastewater. These experiments demonstrated the potential for biocides to significantly decrease iron reduction rates immediately following a spill and demonstrated how microbial communities previously exposed to UOG wastewater may be more resilient to additional spills.IMPORTANCEOrganic components of UOG wastewater can alter microbial communities and biogeochemical processes, which could alter the rates of essential natural attenuation processes. These findings provide new insights into microbial responses following a release of UOG wastewaters and are critical for identifying strategies for the remediation and natural attenuation of impacted environments.

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Methane-related changes in prokaryotes along geochemical profiles in sediments of Lake Kinneret (Israel)

Biogeosciences ◽

10.5194/bg-12-2847-2015 ◽

2015 ◽

Vol 12 (10) ◽

pp. 2847-2860 ◽

Cited By ~ 12

Author(s):

I. Bar-Or ◽

E. Ben-Dov ◽

A. Kushmaro ◽

W. Eckert ◽

O. Sivan

Keyword(s):

Community Structure ◽

Microbial Community ◽

Methane Oxidation ◽

Microbial Community Structure ◽

Iron Reduction ◽

Sulfate Reducing Bacteria ◽

Lake Kinneret ◽

Anaerobic Oxidation Of Methane ◽

Sulfate Reducing ◽

Reducing Bacteria

Abstract. Microbial methane oxidation is the primary control on the emission of the greenhouse gas methane into the atmosphere. In terrestrial environments, aerobic methanotrophic bacteria are largely responsible for this process. In marine sediments, a coupling of anaerobic oxidation of methane (AOM) with sulfate reduction, often carried out by a consortium of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria, consumes almost all methane produced within those sediments. Motivated by recent evidence for AOM with iron(III) in Lake Kinneret sediments, the goal of the present study was to link the geochemical gradients in the lake porewater to the microbial community structure. Screening of archaeal 16S rRNA gene sequences revealed a shift from hydrogenotrophic to acetoclastic methanogens with depth. The observed changes in microbial community structure suggest possible direct and indirect mechanisms for the AOM coupled to iron reduction in deep sediments. The percentage of members of the Nitrospirales order increased with depth, suggesting their involvement in iron reduction together with Geobacter genus and "reverse methanogenesis". An indirect mechanism through sulfate and ANME seems less probable due to the absence of ANME sequences. This is despite the abundant sequences related to sulfate-reducing bacteria (Deltaproteobacteria) together with the occurrence of dsrA in the deep sediment that could indicate the production of sulfate (disproportionation) from S0 for sulfate-driven AOM. The presence of the functional gene pmoA in the deep anoxic sediment together with sequences related to Methylococcales suggests the existence of a second unexpected indirect pathway – aerobic methane oxidation pathway in an anaerobic environment.

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The microbial community structure change of an anaerobic ammonia oxidation reactor in response to decreasing temperatures

Environmental Science and Pollution Research ◽

10.1007/s11356-018-3449-1 ◽

2018 ◽

Vol 25 (35) ◽

pp. 35330-35341 ◽

Cited By ~ 4

Author(s):

Weigang Wang ◽

Yuan Yan ◽

Chengkang Song ◽

Mianli Pan ◽

Yayi Wang

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Community Structure ◽

Ammonia Oxidation ◽

Structure Change ◽

Anaerobic Ammonia Oxidation ◽

Oxidation Reactor

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Temporal dynamics of microbial community structure and its effect on arsenic mobilization and transformation in Quaternary aquifers of the central Yangtze River Basin

Environmental Arsenic in a Changing World ◽

10.1201/9781351046633-57 ◽

2019 ◽

pp. 139-140

Author(s):

T.L. Zheng ◽

Y. Deng ◽

H.C. Jiang ◽

Y.X. Wang

Keyword(s):

Community Structure ◽

Microbial Community ◽

River Basin ◽

Microbial Community Structure ◽

Yangtze River ◽

Temporal Dynamics ◽

Yangtze River Basin ◽

Arsenic Mobilization ◽

Quaternary Aquifers

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Methane related changes in prokaryotic activity along geochemical profiles in sediments of Lake Kinneret (Israel)

Biogeosciences Discussions ◽

10.5194/bgd-11-9813-2014 ◽

2014 ◽

Vol 11 (6) ◽

pp. 9813-9852 ◽

Cited By ~ 1

Author(s):

I. Bar Or ◽

E. Ben-Dov ◽

A. Kushmaro ◽

W. Eckert ◽

O. Sivan

Keyword(s):

Community Structure ◽

Microbial Community ◽

16S Rrna ◽

Microbial Community Structure ◽

Iron Reduction ◽

Lake Kinneret ◽

Community Diversity ◽

Rrna Gene ◽

Anaerobic Oxidation Of Methane ◽

Deep Sediments

Abstract. Microbial methane oxidation process (methanotrophy) is the primary control on the emission of the greenhouse gas methane (CH4) to the atmosphere. In terrestrial environments, aerobic methanotrophic bacteria are mainly responsible for oxidizing the methane. In marine sediments the coupling of the anaerobic oxidation of methane (AOM) with sulfate reduction, often by a consortium of anaerobic methanotrophic archaea (ANME) and sulfate reducing bacteria, was found to consume almost all the upward diffusing methane. Recently, we showed geochemical evidence for AOM driven by iron reduction in Lake Kinneret (LK) (Israel) deep sediments and suggested that this process can be an important global methane sink. The goal of the present study was to link the geochemical gradients found in the porewater (chemical and isotope profiles) with possible changes in microbial community structure. Specifically, we examined the possible shift in the microbial community in the deep iron-driven AOM zone and its similarity to known sulfate driven AOM populations. Screening of archaeal 16S rRNA gene sequences revealed Thaumarchaeota and Euryarchaeota as the dominant phyla in the sediment. Thaumarchaeota, which belongs to the family of copper containing membrane-bound monooxgenases, increased with depth while Euryarchaeota decreased. This may indicate the involvement of Thaumarchaeota, which were discovered to be ammonia oxidizers but whose activity could also be linked to methane, in AOM in the deep sediment. ANMEs sequences were not found in the clone libraries, suggesting that iron-driven AOM is not through sulfate. Bacterial 16S rRNA sequences displayed shifts in community diversity with depth. Proteobacteria and Chloroflexi increased with depth, which could be connected with their different dissimilatory anaerobic processes. The observed changes in microbial community structure suggest possible direct and indirect mechanisms for iron-driven AOM in deep sediments.

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