scholarly journals Grazing weakens competitive interactions between active methanotrophs and nitrifiers modulating greenhouse-gas emissions in grassland soils

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Hong Pan ◽  
Haojie Feng ◽  
Yaowei Liu ◽  
Chun-Yu Lai ◽  
Yuping Zhuge ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Ghg Emissions ◽  
Stable Isotope Probing ◽  
Competitive Interactions ◽  
Major Advance ◽  
Grassland Soils ◽  
Grassland Ecosystems ◽  
Underlying Mechanisms ◽  
Grazed Grassland

AbstractGrassland soils serve as a biological sink and source of the potent greenhouse gases (GHG) methane (CH4) and nitrous oxide (N2O). The underlying mechanisms responsible for those GHG emissions, specifically, the relationships between methane- and ammonia-oxidizing microorganisms in grazed grassland soils are still poorly understood. Here, we characterized the effects of grazing on in situ GHG emissions and elucidated the putative relations between the active microbes involving in methane oxidation and nitrification activity in grassland soils. Grazing significantly decreases CH4 emissions while it increases N2O emissions basing on 14-month in situ measurement. DNA-based stable isotope probing (SIP) incubation experiment shows that grazing decreases both methane oxidation and nitrification processes and decreases the diversity of active methanotrophs and nitrifiers, and subsequently weakens the putative competition between active methanotrophs and nitrifiers in grassland soils. These results constitute a major advance in our understanding of putative relationships between methane- and ammonia-oxidizing microorganisms and subsequent effects on nitrification and methane oxidation, which contribute to a better prediction and modeling of future balance of GHG emissions and active microbial communities in grazed grassland ecosystems.

In situ mercaptosilane-assisted confinement of Pd nanoparticles in Beta for high-efficient methane oxidation

2021 ◽  
Author(s):  
Liling Zhang ◽  
Junfei Chen ◽  
Haolin Yang ◽  
Xiaohan Wang ◽  
Zebao Rui
Keyword(s):  
Methane Oxidation ◽  
Pd Nanoparticles ◽  
High Efficient

Remotely sensed temperature is a proxy of greenhouse gas emissions in intact and managed peatlands

2021 ◽  
Author(s):  
Ain Kull ◽  
Iuliia Burdun ◽  
Gert Veber ◽  
Oleksandr Karasov ◽  
Martin Maddison ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Water Table ◽  
Ecosystem Respiration ◽  
Ghg Emissions ◽  
Remotely Sensed ◽  
Water Table Depth ◽  
Gas Emissions

<p>Besides water table depth, soil temperature is one of the main drivers of greenhouse gas (GHG) emissions in intact and managed peatlands. In this work, we evaluate the performance of remotely sensed land surface temperature (LST) as a proxy of greenhouse gas emissions in intact, drained and extracted peatlands. For this, we used chamber-measured carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) data from seven peatlands in Estonia collected during vegetation season in 2017–2020. Additionally, we used temperature and water table depth data measured in situ. We studied relationships between CO<sub>2</sub>, CH<sub>4</sub>, in-situ parameters and remotely sensed LST from Landsat 7 and 8, and MODIS Terra. Results of our study suggest that LST has stronger relationships with surface and soil temperature as well as with ecosystem respiration (R<sub>eco</sub>) over drained and extracted sites than over intact ones. Over the extracted cites the correlation between R<sub>eco</sub> CO<sub>2</sub> and LST is 0.7, and over the drained sites correlation is 0.5. In natural sites, we revealed a moderate positive relationship between LST and CO<sub>2</sub> emitted in hollows (correlation is 0.6) while it is weak in hummocks (correlation is 0.3). Our study contributes to the better understanding of relationships between greenhouse gas emissions and their remotely sensed proxies over peatlands with different management status and enables better spatial assessment of GHG emissions in drainage affected northern temperate peatlands.</p>

RyR1 exhibits lower gain of CICR activity than RyR3 in the SR: evidence for selective stabilization of RyR1 channel

2004 ◽  
Vol 287 (1) ◽  
pp. C36-C45 ◽  
Author(s):  
Takashi Murayama ◽  
Yasuo Ogawa
Keyword(s):  
Binding Sites ◽  
Skeletal Muscles ◽  
Specific Activity ◽  
Adenine Nucleotides ◽  
Minor Effect ◽  
Mammalian Skeletal Muscle ◽  
Selective Stabilization ◽  
Underlying Mechanisms ◽  
A Minor

We showed that frog α-ryanodine receptor (α-RyR) had a lower gain of Ca2+-induced Ca2+ release (CICR) activity than β-RyR in sarcoplasmic reticulum (SR) vesicles, indicating selective “stabilization” of the former isoform (Murayama T and Ogawa Y. J Biol Chem 276: 2953–2960, 2001). To know whether this is also the case with mammalian RyR1, we determined [3H]ryanodine binding of RyR1 and RyR3 in bovine diaphragm SR vesicles. The value of [3H]ryanodine binding (B) was normalized by the number of maximal binding sites (Bmax), whereby the specific activity of each isoform was expressed. This B/Bmax expression demonstrated that ryanodine binding of individual channels for RyR1 was <15% that for RyR3. Responses to Ca2+, Mg2+, adenine nucleotides, and caffeine were not substantially different between in situ and purified isoforms. These results suggest that the gain of CICR activity of RyR1 is markedly lower than that of RyR3 in mammalian skeletal muscle, indicating selective stabilization of RyR1 as is true of frog α-RyR. The stabilization was partly eliminated by FK506 and partly by solubilization of the vesicles with CHAPS, each of which was additive to the other. In contrast, high salt, which greatly enhances [3H]ryanodine binding, caused only a minor effect on the stabilization of RyR1. None of the T-tubule components, coexisting RyR3, or calmodulin was the cause. The CHAPS-sensitive intra- and intermolecular interactions that are common between mammalian and frog skeletal muscles and the isoform-specific inhibition by FKBP12, which is characteristic of mammals, are likely to be the underlying mechanisms.

scholarly journals Anaerobic bacterial degradation of protein and lipid macromolecules in subarctic marine sediment

2020 ◽  
Author(s):  
Claus Pelikan ◽  
Kenneth Wasmund ◽  
Clemens Glombitza ◽  
Bela Hausmann ◽  
Craig W. Herbold ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Marine Sediment ◽  
Volatile Fatty Acids ◽  
Degradation Products ◽  
Stable Isotope Probing ◽  
Bacterial Degradation ◽  
Rrna Gene ◽  
Genomic Features ◽  
Carbon Processing

AbstractMicroorganisms in marine sediments play major roles in marine biogeochemical cycles by mineralizing substantial quantities of organic matter from decaying cells. Proteins and lipids are abundant components of necromass, yet the taxonomic identities of microorganisms that actively degrade them remain poorly resolved. Here, we revealed identities, trophic interactions, and genomic features of bacteria that degraded 13C-labeled proteins and lipids in cold anoxic microcosms containing sulfidic subarctic marine sediment. Supplemented proteins and lipids were rapidly fermented to various volatile fatty acids within 5 days. DNA-stable isotope probing (SIP) suggested Psychrilyobacter atlanticus was an important primary degrader of proteins, and Psychromonas members were important primary degraders of both proteins and lipids. Closely related Psychromonas populations, as represented by distinct 16S rRNA gene variants, differentially utilized either proteins or lipids. DNA-SIP also showed 13C-labeling of various Deltaproteobacteria within 10 days, indicating trophic transfer of carbon to putative sulfate-reducers. Metagenome-assembled genomes revealed the primary hydrolyzers encoded secreted peptidases or lipases, and enzymes for catabolism of protein or lipid degradation products. Psychromonas species are prevalent in diverse marine sediments, suggesting they are important players in organic carbon processing in situ. Together, this study provides new insights into the identities, functions, and genomes of bacteria that actively degrade abundant necromass macromolecules in the seafloor.

scholarly journals Mitochondria Endoplasmic Reticulum Contact Sites (MERCs): Proximity Ligation Assay as a Tool to Study Organelle Interaction

2021 ◽  
Vol 9 ◽  
Author(s):  
Sara Benhammouda ◽  
Anjali Vishwakarma ◽  
Priya Gatti ◽  
Marc Germain
Keyword(s):  
Endoplasmic Reticulum ◽  
Fluorescence Probes ◽  
Proximity Ligation Assay ◽  
Proximity Ligation ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Endogenous Proteins ◽  
Underlying Mechanisms

Organelles cooperate with each other to regulate vital cellular homoeostatic functions. This occurs through the formation of close connections through membrane contact sites. Mitochondria-Endoplasmic-Reticulum (ER) contact sites (MERCS) are one of such contact sites that regulate numerous biological processes by controlling calcium and metabolic homeostasis. However, the extent to which contact sites shape cellular biology and the underlying mechanisms remain to be fully elucidated. A number of biochemical and imaging approaches have been established to address these questions, resulting in the identification of a number of molecular tethers between mitochondria and the ER. Among these techniques, fluorescence-based imaging is widely used, including analysing signal overlap between two organelles and more selective techniques such as in-situ proximity ligation assay (PLA). While these two techniques allow the detection of endogenous proteins, preventing some problems associated with techniques relying on overexpression (FRET, split fluorescence probes), they come with their own issues. In addition, proper image analysis is required to minimise potential artefacts associated with these methods. In this review, we discuss the protocols and outline the limitations of fluorescence-based approaches used to assess MERCs using endogenous proteins.

scholarly journals Urban greenhouse gas emissions from the Berlin area: A case study using airborne CO2 and CH4 in situ observations in summer 2018

2020 ◽  
Author(s):  
Theresa Klausner ◽  
Mariano Mertens ◽  
Heidi Huntrieser ◽  
Michal Galkowski ◽  
Gerrit Kuhlmann ◽  
...  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Urban Areas ◽  
Ghg Emissions ◽  
Capital City ◽  
Detailed Knowledge ◽  
Emission Flux ◽  
Gas Emissions ◽  
Mixing Ratios

&lt;p&gt;Urban areas are recognised as a significant source of greenhouse gas emissions (GHG), such as carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) and methane (CH&lt;sub&gt;4&lt;/sub&gt;). The total amount of urban GHG emissions, especially for CH&lt;sub&gt;4&lt;/sub&gt;, however, is not well quantified. Here we report on airborne in situ measurements using a Picarro G1301-m analyser aboard the DLR Cessna Grand Caravan to study GHG emissions downwind of the German capital city Berlin. In total, five aircraft-based mass balance experiments were conducted in July 2018 within the Urban Climate Under Change [UC]&lt;sup&gt;2&lt;/sup&gt; project. The detection and isolation of the Berlin plume was often challenging because of comparatively small GHG signals above variable atmospheric background concentrations. However, on July 20&lt;sup&gt;th&lt;/sup&gt; enhancements of up to 4 ppm CO&lt;sub&gt;2&lt;/sub&gt; and 21 ppb CH&lt;sub&gt;4&lt;/sub&gt; were observed over a horizontal extent of roughly 45 to 65 km downwind of Berlin. These enhanced mixing ratios are clearly distinguishable from the background and can partly be assigned to city emissions. The estimated CO&lt;sub&gt;2&lt;/sub&gt; emission flux of 1.39 &amp;#177; 0.75 t s&lt;sup&gt;-1 &lt;/sup&gt;is in agreement with current inventories, while the CH&lt;sub&gt;4&lt;/sub&gt; emission flux of 5.20 &amp;#177; 1.61 kg s&lt;sup&gt;-1&lt;/sup&gt; is almost two times larger than the highest reported value in the inventories. We localized the source area with HYSPLIT trajectory calculations and the high resolution numerical model MECO(n) (down to ~1 km), and investigated the contribution from sewage-treatment plants and waste deposition to CH&lt;sub&gt;4&lt;/sub&gt;, which are treated differently by the emission inventories. Our work highlights the importance of a) strong CH&lt;sub&gt;4&lt;/sub&gt; sources in the surroundings of Berlin and b) a detailed knowledge of GHG inflow mixing ratios to suitably estimate emission rates.&lt;/p&gt;

scholarly journals Comparative Life Cycle Assessment of Merging Recycling Methods for Spent Lithium Ion Batteries

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6263
Author(s):  
Zhiwen Zhou ◽  
Yiming Lai ◽  
Qin Peng ◽  
Jun Li
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Ghg Emissions ◽  
Acid Leaching ◽  
Lithium Ion ◽  
H2o2 Production ◽  
Life Cycle Impact ◽  
Regeneration Phase ◽  
Hydrometallurgical Method

An urgent demand for recycling spent lithium-ion batteries (LIBs) is expected in the forthcoming years due to the rapid growth of electrical vehicles (EV). To address these issues, various technologies such as the pyrometallurgical and hydrometallurgical method, as well as the newly developed in-situ roasting reduction (in-situ RR) method were proposed in recent studies. This article firstly provides a brief review on these emerging approaches. Based on the overview, a life cycle impact of these methods for recovering major component from one functional unit (FU) of 1 t spent EV LIBs was estimated. Our results showed that in-situ RR exhibited the lowest energy consumption and greenhouse gas (GHG) emissions of 4833 MJ FU−1 and 1525 kg CO2-eq FU−1, respectively, which only accounts for ~23% and ~64% of those for the hydrometallurgical method with citric acid leaching. The H2O2 production in the regeneration phase mainly contributed the overall impact for in-situ RR. The transportation distance for spent EV LIBs created a great hurdle to the reduction of the life cycle impact if the feedstock was transported by a 3.5–7.5 t lorry. We therefore suggest further optimization of the spatial distribution of the recycling facilities and reduction in the utilization of chemicals.

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