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Frontiers in Microbiology 2024Climate change is one of the main challenges, and it poses a tough challenge to the agriculture industry globally. Additionally, greenhouse gas (GHG) emissions are the...
Climate change is one of the main challenges, and it poses a tough challenge to the agriculture industry globally. Additionally, greenhouse gas (GHG) emissions are the main contributor to climate change; however, croplands are a prominent source of GHG emissions. Yet this complex challenge can be mitigated through climate-smart agricultural practices. Conservation tillage is commonly known to preserve soil and mitigate environmental change by reducing GHG emissions. Nonetheless, there is still a paucity of information on the influences of conservation tillage on wheat yield, soil properties, and GHG flux, particularly in the semi-arid Dingxi belt. Hence, in order to fill this gap, different tillage systems, namely conventional tillage (CT) control, straw incorporation with conventional tillage (CTS), no-tillage (NT), and stubble return with no-tillage (NTS), were laid at Dingxi, Gansu province of China, under a randomized complete block design with three replications to examine their impacts on yield, soil properties, and GHG fluxes. Results depicted that different conservative tillage systems (CTS, NTS, and NT) significantly ( < 0.05) increased the plant height, number of spikes per plant, seed number per meter square, root yield, aboveground biomass yield, thousand-grain weight, grain yield, and dry matter yield compared with CT. Moreover, these conservation tillage systems notably improved the soil properties (soil gravimetric water content, water-filled pore space, water storage, porosity, aggregates, saturated hydraulic conductivity, organic carbon, light fraction organic carbon, carbon storage, microbial biomass carbon, total nitrogen, available nitrogen storage, microbial biomass nitrogen, total phosphorous, available phosphorous, total potassium, available potassium, microbial counts, urease, alkaline phosphatase, invertase, cellulase, and catalase) while decreasing the soil temperature and bulk density over CT. However, CTS, NTS, and NT had non-significant effects on ECe, pH, and stoichiometric properties (C:N ratio, C:P ratio, and N:P ratio). Additionally, conservation-based tillage regimes NTS, NT, and CTS significantly ( < 0.05) reduced the emission and net global warming potential of greenhouse gases (carbon dioxide, methane, and nitrous oxide) by 23.44, 19.57, and 16.54%, respectively, and decreased the greenhouse gas intensity by 23.20, 29.96, and 18.72%, respectively, over CT. We conclude that NTS is the best approach to increasing yield, soil and water conservation, resilience, and mitigation of agroecosystem capacity.
PubMed: 38894971
DOI: 10.3389/fmicb.2024.1356426 -
Frontiers in Microbiology 2024The diazotrophic cyanobacterium has been recognized as a potentially significant contributor to aerobic methane generation via several mechanisms including the...
The diazotrophic cyanobacterium has been recognized as a potentially significant contributor to aerobic methane generation via several mechanisms including the utilization of methylphophonate (MPn) as a source of phosphorus. Currently, there is no information about how environmental factors regulate methane production by . Here, we grew IMS101 at five temperatures ranging from 16 to 31°C, and found that its methane production rates increased with rising temperatures to peak (1.028 ± 0.040 nmol CH μmol POC day) at 27°C, and then declined. Its specific growth rate changed from 0.03 ± 0.01 d to 0.34 ± 0.02 d, with the optimal growth temperature identified between 27 and 31°C. Within the tested temperature range the Q for the methane production rate was 4.6 ± 0.7, indicating a high sensitivity to thermal changes. In parallel, the methane production rates showed robust positive correlations with the assimilation rates of carbon, nitrogen, and phosphorus, resulting in the methane production quotients (molar ratio of carbon, nitrogen, or phosphorus assimilated to methane produced) of 227-494 for carbon, 40-128 for nitrogen, and 1.8-3.4 for phosphorus within the tested temperature range. Based on the experimental data, we estimated that the methane released from can offset about 1% of its CO mitigation effects.
PubMed: 38894967
DOI: 10.3389/fmicb.2024.1396369 -
Sensors (Basel, Switzerland) May 2024New process developments linked to Power to X (energy storage or energy conversion to another form of energy) require tools to perform process monitoring. The main gases...
New process developments linked to Power to X (energy storage or energy conversion to another form of energy) require tools to perform process monitoring. The main gases involved in these types of processes are H, CO, CH, and CO. Because of the non-selectivity of the sensors, a multi-sensor matrix has been built in this work based on commercial sensors having very different transduction principles, and, therefore, providing richer information. To treat the data provided by the sensor array and extract gas mixture composition (nature and concentration), linear ( "MLR-OLS" and "MLR-PLS") and non-linear ( "ANN") models have been built. The MLR-OLS model was disqualified during the training phase since it did not show good results even in the training phase, which could not lead to effective predictions during the validation phase. Then, the performances of MLR-PLS and ANN were evaluated with validation data. Good concentration predictions were obtained in both cases for all the involved analytes. However, in the case of methane, better prediction performances were obtained with ANN, which is consistent with the fact that the MOX sensor's response to CH is logarithmic, whereas only linear sensor responses were obtained for the other analytes. Finally, prediction tests performed on one-year aged sensor platforms revealed that PLS model predictions on aged platforms mainly suffered from concentration offsets and that ANN predictions mainly suffered from a drop of sensitivity.
PubMed: 38894290
DOI: 10.3390/s24113499 -
Sensors (Basel, Switzerland) May 2024Quantifying and controlling fugitive methane emissions from oil and gas facilities remains essential for addressing climate goals, but the costs associated with...
Quantifying and controlling fugitive methane emissions from oil and gas facilities remains essential for addressing climate goals, but the costs associated with monitoring millions of production sites remain prohibitively expensive. Current thinking, supported by measurement and simple dispersion modelling, assumes single-digit parts-per-million instrumentation is required. To investigate instrument response, the inlets of three trace-methane (sub-ppm) analyzers were collocated on a facility designed to release gas of known composition at known flow rates between 0.4 and 5.2 kg CH h from simulated oil and gas infrastructure. Methane mixing ratios were measured by each instrument at 1 Hertz resolution over nine hours. While mixing ratios reported by a cavity ring-down spectrometer (CRDS)-based instrument were on average 10.0 ppm (range 1.8 to 83 ppm), a mid-infrared laser absorption spectroscopy (MIRA)-based instrument reported short-lived mixing ratios far larger than expected (range 1.8 to 779 ppm) with a similar nine-hour average to the CRDS (10.1 ppm). We suggest the peaks detected by the MIRA are likely caused by a micrometeorological phenomenon, where vortex shedding has resulted in heterogeneous methane plumes which only the MIRA can observe. Further analysis suggests an instrument like the MIRA (an optical-cavity-based instrument with cavity size ≤10 cm measuring at ≥2 Hz with air flow rates in the order of ≤0.3 slpm at distances of ≤20 m from the source) but with a higher detection limit (25 ppm) could detect enough of the high-concentration events to generate representative 20 min-average methane mixing ratios. Even though development of a lower-cost, high-precision, high-accuracy instrument with a 25 ppm detection threshold remains a significant problem, this has implications for the use of instrumentation with higher detection thresholds, resulting in the reduction in cost to measure methane emissions and providing a mechanism for the widespread deployment of effective leak detection and repair programs for all oil and gas infrastructure.
PubMed: 38894198
DOI: 10.3390/s24113407 -
Materials (Basel, Switzerland) May 2024The x%Ni/SmO-MnO (x = 0, 10, 15, 20) catalysts derived from SmMnO mullite were prepared by solution combustion and impregnation method; auto-thermal reforming (ATR) of...
The x%Ni/SmO-MnO (x = 0, 10, 15, 20) catalysts derived from SmMnO mullite were prepared by solution combustion and impregnation method; auto-thermal reforming (ATR) of acetic acid (HAc) for hydrogen production was used to explore the metal-support effect induced by Ni loadings on the catalytic reforming activity and product distribution. The 15%Ni/SmO-MnO catalyst exhibited optimal catalytic performance, which can be due to the appropriate Ni loading inducing a strong metal-support interaction to form a stable Ni/SmO-MnO active center, while side reactions, such as methanation and ketonization, were well suppressed. According to characterizations, SmO-MnO mixed oxides derived from SmMnO mullite were formed with oxygen vacancies; nevertheless, loading of Ni metal further promoted the formation of oxygen vacancies, thus enhancing adsorption and activation of oxygen-containing intermediate species and resulting in higher reactivity with HAc conversion near 100% and hydrogen yield at 2.62 mol-H/mol-HAc.
PubMed: 38893754
DOI: 10.3390/ma17112490 -
Molecules (Basel, Switzerland) May 2024In this study, vermiculite was explored as a support material for nickel catalysts in two key processes in syngas production: dry reforming of methane with CO and steam...
In this study, vermiculite was explored as a support material for nickel catalysts in two key processes in syngas production: dry reforming of methane with CO and steam reforming of ethanol. The vermiculite underwent acid or base treatment, followed by the preparation of Ni catalysts through incipient wetness impregnation. Characterization was conducted using various techniques, including X-ray diffraction (XRD), SEM-EDS, FTIR, and temperature-programmed reduction (H-TPR). TG-TD analyses were performed to assess the formation of carbon deposits on spent catalysts. The Ni-based catalysts were used in reaction tests without a reduction pre-treatment. Initially, raw vermiculite-supported nickel showed limited catalytic activity in the dry reforming of methane. After acid (Ni/VTA) or base (Ni/VTB) treatment, vermiculite proved to be an effective support for nickel catalysts that displayed outstanding performance, achieving high methane conversion and hydrogen yield. The acidic treatment improved the reduction of nickel species and reduced carbon deposition, outperforming the Ni over alkali treated support. The prepared catalysts were also evaluated in ethanol steam reforming under various conditions including temperature, water/ethanol ratio, and space velocity, with acid-treated catalysts confirming the best performance.
PubMed: 38893456
DOI: 10.3390/molecules29112575 -
Molecules (Basel, Switzerland) May 2024Leach bed reactors (LBRs) are dry anaerobic systems that can handle feedstocks with high solid content, like chicken manure, with minimal water addition. In this study,...
Leach bed reactors (LBRs) are dry anaerobic systems that can handle feedstocks with high solid content, like chicken manure, with minimal water addition. In this study, the chicken manure was mixed with zeolite, a novel addition, and packed in the LBR to improve biogas production. The resulting leachate was then processed in a continuous stirred tank reactor (CSTR), where most of the methane was produced. The supernatant of the CSTR was returned to the LBR. The batch mode operation of the LBR led to a varying methane production rate (MPR) with a peak in the beginning of each batch cycle when the leachate was rich in organic matter. Comparing the MPR in both systems, the peaks in the zeolite system were higher and more acute than in the control system, which was under stress, as indicated by the acetate accumulation at 2328 mg L. Moreover, the presence of zeolite in the LBR played a crucial role, increasing the overall methane yield from 0.142 (control experiment) to 0.171 NL CH per g of volatile solids of chicken manure entering the system at a solid retention time of 14 d. Zeolite also improved the stability of the system. The ammonia concentration increased gradually due to the little water entering the system and reached 3220 mg L (control system) and 2730 mg L (zeolite system) at the end of the experiment. It seems that zeolite favored the accumulation of the ammonia at a lower rate (14.0 mg L d) compared to the control experiment (17.3 mg L d). The microbial analysis of the CSTR fed on the leachate from the LBR amended with zeolite showed a higher relative abundance of (83.6%) compared to the control experiment (69.1%). Both CSTRs established significantly different bacterial profiles from the inoculum after 120 days of operation ( < 0.05). Regarding the archaeal communities, there were no significant statistical differences between the CSTRs and the inoculum ( > 0.05).
Topics: Zeolites; Animals; Chickens; Manure; Anaerobiosis; Biodegradation, Environmental; Methane; Bioreactors; Biofuels; Ammonia
PubMed: 38893444
DOI: 10.3390/molecules29112568 -
Molecules (Basel, Switzerland) May 2024This review addresses the critical issue of a rapidly increasing worldwide waste stream and the need for sustainable management. The paper proposes an integrated... (Review)
Review
This review addresses the critical issue of a rapidly increasing worldwide waste stream and the need for sustainable management. The paper proposes an integrated transformation toward a next-generation methanization process, which leads not only to treating waste but also to converting it into higher value compounds and greener energy. Although the current and commonly used anaerobic digestion process is useful for biogas production, it presents limitations of resource exploitation and some negative environmental impacts. Focusing on the acidogenic stage in waste stream processing, the paper discusses the recent strategies to enhance the recovery of volatile fatty acids (VFAs). These acids serve as precursors for synthesizing a variety of biochemicals and biofuels, offering higher value products than solely energy recovery and soil fertilizers. Additionally, the importance of recycling the fermentation residues back into the biorefinery process is highlighted. This recycling not only generates additional VFAs but also contributes to generating clean energy, thereby enhancing the overall sustainability and efficiency of the waste management system. Moreover, the review discusses the necessity to integrate life cycle assessment (LCA) and techno-economic analysis (TEA) to evaluate the environmental impacts, sustainability, and processing costs of the proposed biorefinery.
Topics: Fatty Acids, Volatile; Biofuels; Methane; Anaerobiosis; Fermentation; Waste Management; Recycling
PubMed: 38893350
DOI: 10.3390/molecules29112477 -
Molecules (Basel, Switzerland) May 2024Iron porphyrins are known to provide CH as an eight-electron reduction product of CO in a photochemical reaction. However, there are still some aspects of the reaction...
Iron porphyrins are known to provide CH as an eight-electron reduction product of CO in a photochemical reaction. However, there are still some aspects of the reaction mechanism that remain unclear. In this study, we synthesized iron porphyrin dimers and carried out the photochemical CO reduction reactions in -dimethylacetamide (DMA) containing a photosensitizer in the presence of 1,3-dimethyl-2-phenyl-2,3-dihydro-1-benzo[d]imidazole (BIH) as an electron donor. We found that, despite a low catalytic turnover number, CH was produced only when these porphyrins were facing each other. The close proximity of the cyclic dimers, distinguishing them from a linear Fe porphyrin dimer and monomers, induced multi-electron CO reduction, emphasizing the unique role of their structural arrangement in CH formation.
PubMed: 38893329
DOI: 10.3390/molecules29112453 -
International Journal of Molecular... Jun 2024Genome-wide association studies (GWAS) significantly enhance our ability to identify trait-associated genomic variants by considering the host genome. Moreover, the...
Genome-wide association studies (GWAS) significantly enhance our ability to identify trait-associated genomic variants by considering the host genome. Moreover, the hologenome refers to the host organism's collective genetic material and its associated microbiome. In this study, we utilized the hologenome framework, called Hologenome-wide association studies (HWAS), to dissect the architecture of complex traits, including milk yield, methane emissions, rumen physiology in cattle, and gut microbial composition in pigs. We employed four statistical models: (1) GWAS, (2) Microbial GWAS (M-GWAS), (3) HWAS-CG (hologenome interaction estimated using COvariance between Random Effects Genome-based restricted maximum likelihood (CORE-GREML)), and (4) HWAS-H (hologenome interaction estimated using the Hadamard product method). We applied Bonferroni correction to interpret the significant associations in the complex traits. The GWAS and M-GWAS detected one and sixteen significant SNPs for milk yield traits, respectively, whereas the HWAS-CG and HWAS-H each identified eight SNPs. Moreover, HWAS-CG revealed four, and the remaining models identified three SNPs each for methane emissions traits. The GWAS and HWAS-CG detected one and three SNPs for rumen physiology traits, respectively. For the pigs' gut microbial composition traits, the GWAS, M-GWAS, HWAS-CG, and HWAS-H identified 14, 16, 13, and 12 SNPs, respectively. We further explored these associations through SNP annotation and by analyzing biological processes and functional pathways. Additionally, we integrated our GWA results with expression quantitative trait locus (eQTL) data using transcriptome-wide association studies (TWAS) and summary-based Mendelian randomization (SMR) methods for a more comprehensive understanding of SNP-trait associations. Our study revealed hologenomic variability in agriculturally important traits, enhancing our understanding of host-microbiome interactions.
Topics: Animals; Genome-Wide Association Study; Polymorphism, Single Nucleotide; Cattle; Swine; Quantitative Trait Loci; Gastrointestinal Microbiome; Rumen; Phenotype; Methane; Milk; Genome
PubMed: 38892420
DOI: 10.3390/ijms25116234