scholarly journals Methanotrophic Community Detected by DNA-SIP at Bertioga’s Mangrove Area, Southeast Brazil

2020 ◽  
Author(s):  
Débora do Carmo Linhares ◽  
Flávia Talarico Saia ◽  
Rubens Tadeu Delgado Duarte ◽  
Cristina Rossi Nakayama ◽  
Itamar Soares de Melo ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Nitrate Reduction ◽  
Taxonomic Diversity ◽  
Stable Isotope Probing ◽  
Methanotrophic Bacteria ◽  
Mangrove Area ◽  
Oxygen Starvation ◽  
Aerobic Methanotrophs ◽  
Oxygen Tensions ◽  
Bacterial Groups

AbstractMethanotrophic bacteria can use methane as sole carbon and energy source. Its importance in the environment is related to the mitigation of methane emissions from soil and water to the atmosphere. Brazilian mangroves are highly productive, have potential to methane production, and it is inferred that methanotrophic community is of great importance for this ecosystem. The scope of this study was to investigate the functional and taxonomic diversity of methanotrophic bacteria present in the anthropogenic impacted sediments from Bertioga’s mangrove (SP, Brazil). Sediment sample was cultivated with methane and the microbiota actively involved in methane oxidation was identified by DNA-based stable isotope probing (DNA-SIP) using methane as a labeled substrate. After 4 days of incubation and consumption of 0.7 mmol of methane, the most active microorganisms were related to methanotrophs Methylomonas and Methylobacter as well as to methylotrophic Methylotenera, indicating a possible association of these bacterial groups within a methane derived food chain in the Bertioga mangrove. The abundance of genera Methylomonas, able to couple methane oxidation to nitrate reduction, may indicate that under low dissolved oxygen tensions some aerobic methanotrophs could shift to intraerobic methane oxidation to avoid oxygen starvation.

scholarly journals Multiple groups of methanotrophic bacteria mediate methane oxidation in anoxic lake sediments

2021 ◽  
Author(s):  
Guangyi Su ◽  
Jakob Zopfi ◽  
Moritz F. Lehmann
Keyword(s):  
Lake Sediments ◽  
Methane Oxidation ◽  
Methane Emissions ◽  
Type I ◽  
Methanotrophic Bacteria ◽  
Anoxic Sediments ◽  
Anoxic Conditions ◽  
Aerobic Methanotrophs ◽  
Multiple Groups ◽  
Lake Sempach

Freshwater lakes represent an important source of the potent greenhouse gas methane (CH4) to the atmosphere. Methane emissions are regulated to large parts by aerobic (MOx) and anaerobic (AOM) oxidation of methane that are important sinks in lakes. In contrast to marine benthic environments, our knowledge about the modes of AOM and the related methanotrophic microorganisms in anoxic lake sediments is still rudimentary. Here we demonstrate the occurrence of AOM in the anoxic sediments of Lake Sempach (Switzerland), with maximum in situ AOM rates observed within the surface sediment layers in presence of multiple groups of methanotrophic bacteria and various oxidants known to support AOM. However, substrate-amended incubations (with NO2-, NO3-, SO42-, Fe3+ and Mn4+) revealed that none of the electron acceptors previously reported to support AOM enhanced methane turnover in Lake Sempach sediments under anoxic conditions. In contrast, the addition of oxygen to the anoxic sediments resulted in an approximately tenfold increase in methane oxidation relative to the anoxic incubations. Phylogenetic and isotopic evidence indicate that both Type I and Type II aerobic methanotrophs were growing on methane under both oxic and anoxic conditions, although methane assimilation rates were an order of magnitude higher under oxic conditions. While the anaerobic electron acceptor responsible for AOM could not be identified, these findings expand our understanding of the metabolic versatility of canonically aerobic methanotrophs under anoxic conditions, with important implications for future investigations to identify methane oxidation processes. Bacterial AOM by facultative aerobic methane oxidizers might be of much larger environmental significance in reducing methane emissions than previously thought.

A membrane biofilm reactor achieves aerobic methane oxidation coupled to denitrification (AME-D) with high efficiency

2008 ◽  
Vol 58 (1) ◽  
pp. 83-87 ◽  
Author(s):  
O. Modin ◽  
K. Fukushi ◽  
F. Nakajima ◽  
K. Yamamoto
Keyword(s):  
Methane Oxidation ◽  
High Efficiency ◽  
Biofilm Reactor ◽  
Practical Application ◽  
Suspended Culture ◽  
Consumption Ratio ◽  
Membrane Biofilm Reactor ◽  
Nitrate Consumption ◽  
Attached Culture ◽  
Aerobic Methanotrophs

Methane would potentially be an inexpensive, widely available electron donor for denitrification of wastewaters poor in organics. Currently, no methanotrophic microbe is known to denitrify. However, aerobic methane oxidation coupled to denitrification (AME-D) has been observed in several laboratory studies. In the AME-D process, aerobic methanotrophs oxidise methane and release organic metabolites and lysis products, which are used by coexisting denitrifiers as electron donors for denitrification. Due to the presence of oxygen, the denitrification efficiency in terms of methane-to-nitrate consumption is usually low. To improve this efficiency the use of a membrane biofilm reactor was investigated. The denitrification efficiency of an AME-D culture in (1) a suspended growth reactor, and (2) a membrane biofilm reactor was studied. The methane-to-nitrate consumption ratio for the suspended culture was 8.7. For the membrane-attached culture the ratio was 2.2. The results clearly indicated that the membrane-attached biofilm was superior to the suspended culture in terms of denitrification efficiency. This study showed that for practical application of the AME-D process, focus should be placed on development of a biofilm reactor.

scholarly journals Methylocella Species Are Facultatively Methanotrophic

2005 ◽  
Vol 187 (13) ◽  
pp. 4665-4670 ◽  
Author(s):  
Svetlana N. Dedysh ◽  
Claudia Knief ◽  
Peter F. Dunfield
Keyword(s):  
Methane Oxidation ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Methanotrophic Bacteria ◽  
Soluble Methane Monooxygenase ◽  
Cell Counts ◽  
Carbon Compounds ◽  
Methane Fluxes ◽  
The One ◽  
Pcr Targeting

ABSTRACT All aerobic methanotrophic bacteria described to date are unable to grow on substrates containing carbon-carbon bonds. Here we demonstrate that members of the recently discovered genus Methylocella are an exception to this. These bacteria are able to use as their sole energy source the one-carbon compounds methane and methanol, as well as the multicarbon compounds acetate, pyruvate, succinate, malate, and ethanol. To conclusively verify facultative growth, acetate and methane were used as model substrates in growth experiments with the type strain Methylocella silvestris BL2. Quantitative real-time PCR targeting the mmoX gene, which encodes a subunit of soluble methane monooxygenase, showed that copies of this gene increased in parallel with cell counts during growth on either acetate or methane as the sole substrate. This verified that cells possessing the genetic basis of methane oxidation grew on acetate as well as methane. Cloning of 16S rRNA genes and fluorescence in situ hybridization with strain-specific and genus-specific oligonucleotide probes detected no contaminants in cultures. The growth rate and carbon conversion efficiency were higher on acetate than on methane, and when both substrates were provided in excess, acetate was preferably used and methane oxidation was shut down. Our data demonstrate that not all methanotrophic bacteria are limited to growing on one-carbon compounds. This could have major implications for understanding the factors controlling methane fluxes in the environment.

scholarly journals Acetate Repression of Methane Oxidation by Supplemental Methylocella silvestris in a Peat Soil Microcosm

2011 ◽  
Vol 77 (12) ◽  
pp. 4234-4236 ◽  
Author(s):  
M. Tanvir Rahman ◽  
Andrew Crombie ◽  
Hélène Moussard ◽  
Yin Chen ◽  
J. Colin Murrell
Keyword(s):  
Stable Isotope ◽  
Methane Oxidation ◽  
Environmental Samples ◽  
Peat Soil ◽  
Methane Monooxygenase ◽  
Laboratory Culture ◽  
Stable Isotope Probing ◽  
Soil Microcosm ◽  
Content Type

ABSTRACTMethylocellaspp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase ofMethylocella silvestrisin laboratory culture. DNA stable-isotope probing (DNA-SIP) using13C-methane and12C-acetate, carried out withMethylocella-spiked peat soil, showed that acetate also repressed methane oxidation byMethylocellain environmental samples.

scholarly journals Methane distribution and oxidation around the Lena Delta in summer 2013

2017 ◽  
Author(s):  
Ingeborg Bussmann ◽  
Steffen Hackbusch ◽  
Patrick Schaal ◽  
Antje Wichels
Keyword(s):  
Methane Oxidation ◽  
Methane Flux ◽  
Methanotrophic Bacteria ◽  
Riverine Water ◽  
Lena River ◽  
Methane Distribution ◽  
Methane Oxidation Rate ◽  
Mixed Water ◽  
Polar Water ◽  
Lena Delta

Abstract. The Lena River is one of the biggest Russian rivers draining into the Laptev Sea. Due to predicted increasing temperatures, the permafrost areas surrounding the Lena Delta will melt at increasing rates. With this melting, high amounts of methane will reach the waters of the Lena and the adjacent Laptev Sea. Methane oxidation by methanotrophic bacteria is the only biological way to reduce methane concentrations within the system. However, the polar estuary of the Lena River is a challenging environment for bacteria, with strong fluctuations in salinity and temperature. We determined the activity (tracer method) and the abundance (qPCR) of aerobic methanotrophic bacteria. We described the methanotrophic population with MISA; as well as the methane distribution (head space) and other abiotic parameters in the Lena Delta in September 2013. In riverine water (S < 5) we found a median methane concentration of 22 nM, in mixed water (5 < S < 20) the median methane concentration was 19 nM and in polar water (S > 20) a median 28 nM was observed. The Lena River was not the methane source for surface water, and bottom water methane concentrations were mainly influenced by the concentration in surface sediments. However, the methane oxidation rate in riverine and polar water was very similar (0.419 and 0.400 nM/d), but with a higher relative abundance of methanotrophs and a higher estimated diversity with respect to MISA OTUs in the rivine water as compared to polar water. The turnover times of methane ranged from 167 d in mixed water, 91 d in riverine water and only 36 d in polarwater. Also the environmental parameters influencing the methane oxidation rate and the methanotrophic population differed between the water masses. Thus we postulate a riverine methanotrophic population limited by sub-optimal temperatures and substrate concentrations and a polar methanotrophic population being well adapted to the cold and methane poor environment, but limited by the nitrogen content. The diffusive methane flux into the atmosphere ranged from 4–163 µmol m2 d−1 (median 24). For the total methane inventory of the investigated area, the diffusive methane flux was responsible for 8 % loss, compared to only 1 % of the methane consumed by the methanotrophic bacteria within the system.

scholarly journals Nitrate Reduction Stimulates and Is Stimulated by Phenazine-1-Carboxylic Acid Oxidation by Citrobacter portucalensis MBL

mBio ◽  
2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Lev M. Tsypin ◽  
Dianne K. Newman
Keyword(s):  
Gene Expression ◽  
Carboxylic Acid ◽  
Microbial Communities ◽  
Nitrate Reduction ◽  
Acid Oxidation ◽  
Antibiotic Tolerance ◽  
Regulate Gene Expression ◽  
Aromatic Molecules ◽  
Oxygen Starvation ◽  
Regulate Gene

Phenazines are increasingly appreciated for their roles in structuring microbial communities. These tricyclic aromatic molecules have been found to regulate gene expression, be toxic, promote antibiotic tolerance, and promote survival under oxygen starvation.

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