Effects of aeration and organic loading rates on degradation of trichloroethylene in a methanogenic-methanotrophic coupled reactor

Lyew, Darwin; Guiot, Serge R.

doi:10.1007/s00253-003-1224-8

Cited by 18 publications

(18 citation statements)

References 23 publications

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“…The final volume of 20 µL PCR reaction contained 0.2 µL PfuUltra II fusion HS DNA polymerase (Agilent Technologies, Santa Clara, California, USA), 50 µM each forward and reverse primer, 25 µM each dNTPs (Thermo Scientific, Waltham, Massachusetts, USA), 10 µg mL −1 BSA (Thermo Scientific, Waltham, Massachusetts, USA) and 1 ng template DNA. After initial denaturation for 2 min at 95 • C, DNA was amplified in 30 cycles of 30 s 95 • C denaturation, 30 s 55 • C annealing, and 30 s at 72 • C for extension, with a final extension of 2 min at 72 • C. The pmoA subunit of the particulate monooxygenase (pMMO) was amplified with primer pair 189f (5 -xx-GGNGACTGGGACTTCTGG-3 ) and mb661r (5 -yy-CCGGMGCAACGTCYTTACC-3 ) (Holmes et al, 1999;Lyew and Guiot, 2003). The PCR conditions were the same as described for the V4-V5 amplicon.…”

Section: Nucleic Acid Extraction and Sequencingmentioning

confidence: 99%

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Methane-oxidizing seawater microbial communities from an Arctic shelf

et al. 2018

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Abstract. Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydrate. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L −1 , approximately 4.8 times oversaturated relative to atmospheric equilibrium. The group of methaneoxidizing bacteria (MOB) in the natural seawater and incubated seawater was > 97 % dominated by Methylococcales (γ -Proteobacteria). Incubations of seawater under a range of methane concentrations led to loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5 % at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were 4 times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotroph sequences correlated tightly with the rate constant (k ox ) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg −1 were found, Methylobacterium (α-Proteobacteria) was the dominant MOB with a relative abundance of 80 %. Total MOB abundances were very low in sea ice, with maximal fractions found at the icesnow interface (0.1 %), while non-MOB methylotrophs were present in abundances similar to natural seawater communities. The dissimilarities in MOB taxa, methane concentrations, and stable isotope ratios between the sea ice and water column point toward different methane dynamics in the two environments.

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Section: Nucleic Acid Extraction and Sequencingmentioning

confidence: 99%

“…Measurements were performed in fast measurement mode. Dissolved methane concentrations were calculated as described in Magen et al (2014), with the equilibrium constant according to Yamamoto et al (1976).…”

Section: Analytical Procedures 241 Methane Concentration and Stablementioning

confidence: 99%

Methane-oxidizing seawater microbial communities from an Arctic shelf

et al. 2018

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“…PhyloChip analysis from the same study also showed a shift in the structure of the microbial community with distance from the source well from bacteria involved in methanogenesis and reductive dechlorination to methanotrophic bacteria. The co-existence of aerobic methanotrophs and anaerobic methanogens in TAN-29 and TAN-35 planktonic samples is not unusual as methanogens can survive under aerobic conditions by inhabiting biofilms (Lyew and Guiot 2003). Likewise methanotrophs are capable of going dormant under anoxic conditions (Roslev and King 1995).…”

Section: Discussionmentioning

confidence: 98%

“…The following primers were used for the amplification of pMMO (standard curve r 2 = 0.999), 189f (5 0 -GGNGACTGGGACTTC TGG-3 0 ) and mb661r (5 0 -CCGGMGCAACGTCY TTACC-3 0 ) (Lyew and Guiot 2003;Holmes et al 1995). The mmoX portion of sMMO (standard curve r 2 = 0.999) was amplified using primer pair 536f (5 0 -CGCTGTGGAAGGGCATGAAGCG-3 0 ) and 898r (5 0 -GCTCGACCTTGAACTTGGAGCC-3 0 ) (Fuse et al 1998;Lyew and Guiot 2003). Amplification of methanol dehydrogenase genes (standard curve r 2 = 0.994) was performed using the primer pair mxa f1103 (5 0 -GCGGCACCAACTGGGGCTGGT-3 0 ) and mxa r1561 (5 0 -GGGCAGCATGAAGGGC TCCC-3 0 ) (McDonald and Murrell 1997).…”

Section: Dna Extractions For Qpcrmentioning

confidence: 99%

Proteomic and targeted qPCR analyses of subsurface microbial communities for presence of methane monooxygenase

et al. 2011

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The Test Area North (TAN) site at the Idaho National Laboratory near Idaho Falls, ID, USA, sits over a trichloroethylene (TCE) contaminant plume in the Snake River Plain fractured basalt aquifer. Past observations have provided evidence that TCE at TAN is being transformed by biological natural attenuation that may be primarily due to co-metabolism in aerobic portions of the plume by methanotrophs. TCE co-metabolism by methanotrophs is the result of the broad substrate specificity of microbial methane monooxygenase which permits non-specific oxidation of TCE in addition to the primary substrate, methane. Arrays of experimental approaches have been utilized to understand the biogeochemical processes driving intrinsic TCE co-metabolism at TAN. In this study, aerobic methanotrophs were enumerated by qPCR using primers targeting conserved regions of the genes pmoA and mmoX encoding subunits of the particulate MMO (pMMO) and soluble MMO (sMMO) enzymes, respectively, as well as the gene mxa encoding the downstream enzyme methanol dehydrogenase. Identification of proteins in planktonic and biofilm samples from TAN was determined using reverse phase ultraperformance liquid chromatography (UPLC) coupled with a quadrupole-time-of-flight (QToF) mass spectrometer to separate and sequence peptides from trypsin digests of the protein extracts. Detection of MMO in unenriched water samples from TAN provides direct evidence of intrinsic methane oxidation and TCE co-metabolic potential of the indigenous microbial population. Mass spectrometry is also well suited for distinguishing which form of MMO is expressed in situ either soluble or particulate. Using this method, pMMO proteins were found to be abundant in samples collected from wells within and adjacent to the TCE plume at TAN.

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“…The pmoA subunit of the particulate monooxygenase (pMMO) was amplified with primer pair 189f (5´-xx-GGNGACTGGGACTTCTGG-3´) and mb661r (5´-yy-CCGGMGCAACGTCYTTACC-3´) (Holmes et al, 1999;Lyew and Guiot, 2003). The PCR conditions were the same as described for the V4V5 amplicon.…”

Section: Nucleic Acid Extraction and Sequencingmentioning

confidence: 99%

Methane oxidizing seawater microbial communities from an Arctic shelf

Uhlig¹,

Kirkpatrick²,

Dhondt³

et al. 2017

Preprint

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Abstract. Microbial communities of the ocean can consume methane dissolved in seawater before it has a chance to escape to the atmosphere and contribute to greenhouse warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to the atmospheric equilibrium originating in sediments, permafrost and hydrates. Particularly high 10 concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L -1 , approximately 4.8 times oversaturated compared to the atmospheric equilibrium. The group of methane oxidizing bacteria (MOB) in the natural seawater and seawater incubations was >97% dominated by Methylococcacales (γ-Proteobacteria). Incubations of seawater under a range of methane concentrations led to a loss of 15 diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5% at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were four times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotrophs correlated tightly with the rate constant (k ox ) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg -1 were found, Methylobacterium (α-Proteobacteria) 20 was the dominant MOB with a relative abundance of 80%. MOB abundances were very low in sea ice, with maximal fractions found at the ice-snow interface (0.1%), while non-MOB-methlylotrophs were present in abundances compared to natural seawater communities. The differences in MOB taxa and an offset in methane concentration and stable isotope ratios between the ice and the water column point toward different methane cycling processes in both habitats.

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Effects of aeration and organic loading rates on degradation of trichloroethylene in a methanogenic-methanotrophic coupled reactor

Cited by 18 publications

References 23 publications

Methane-oxidizing seawater microbial communities from an Arctic shelf

Methane-oxidizing seawater microbial communities from an Arctic shelf

Proteomic and targeted qPCR analyses of subsurface microbial communities for presence of methane monooxygenase

Methane oxidizing seawater microbial communities from an Arctic shelf

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