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Animal : An International Journal of... May 2024No single enteric CH mitigating strategy has been consistently effective or is readily applicable to ruminants in grassland systems. When CH mitigating strategies are...
No single enteric CH mitigating strategy has been consistently effective or is readily applicable to ruminants in grassland systems. When CH mitigating strategies are effective under grazing conditions, mitigation is mild to moderate at best. A study was conducted to evaluate the potential of combining two CH mitigation strategies deemed feasible to apply in grazing dairy cows, the methanogenesis inhibitor 3-nitrooxypropanol additive (3-NOP) and cottonseed supplementation (CTS), seeking to enhance their individual CH mitigating potential. Forty-eight dairy cows were evaluated in a continuous grazing study and supplemented with either a starch-based concentrate (STA) or one that contained cottonseeds (1.75 kg DM/d; CTS), and with either 19 g/d of 10% 3-NOP (Bovaer®) or the additive's carrier (placebo), in a 2 × 2 factorial arrangement of treatments. Treatments were supplied mixed with a concentrate supplement (5 kg/d as fed) and offered in two equal rations at milking. Methane emissions were measured on weeks 4 and 8 using the sulphur hexafluoride tracer gas technique over a 5-d period. The 3-NOP and CTS treatments tended to interact on absolute CH such that 3-NOP decreased CH by 13.4% with STA, but there was no mitigation with 3-NOP and CTS. Treatment interactions were also obtained for CH yield, where 3-NOP tended to decrease CH when supplied with STA, and tended to increase it with CTS. The increase in CH yield with the CTS diet was driven by a numerical decrease in DM intake. Methane intensity was not affected by the 3-NOP or CTS treatments. Total volatile fatty acids in ruminal fluid were not affected by 3-NOP supplementation, but a reduction in acetate and an increase in propionate proportion occurred, resulting in decreased acetate: propionate. The 3-NOP additive decreased grass intake; however, energy-corrected milk yield and milk composition were largely unaffected. Milk urea increased with 3-NOP supplementation. Combining twice daily supplementation of 3-NOP and CTS did not enhance their CH mitigation potential when fed to grazing dairy cows. The relatively low inhibition of CH production by 3-NOP compared to studies with total mixed rations may result from the mode of delivery (pulse dosed twice daily) and time gap caused by experimental handling and moving of animals to pasture after 3-NOP supplementation in the milking parlour, which could have impaired the synchrony between the additive presence in the rumen and grass intake in paddocks.
PubMed: 38935983
DOI: 10.1016/j.animal.2024.101203 -
Frontiers in Microbiology 2024Microbial inhibition by high ammonia concentrations is a recurring problem that significantly restricts methane formation from intermediate acids, i.e., propionate and...
Microbial inhibition by high ammonia concentrations is a recurring problem that significantly restricts methane formation from intermediate acids, i.e., propionate and acetate, during anaerobic digestion of protein-rich waste material. Studying the syntrophic communities that perform acid conversion is challenging, due to their relatively low abundance within the microbial communities typically found in biogas processes and disruption of their cooperative behavior in pure cultures. To overcome these limitations, this study examined growth parameters and microbial community dynamics of highly enriched mesophilic and ammonia-tolerant syntrophic propionate and acetate-oxidizing communities and analyzed their metabolic activity and cooperative behavior using metagenomic and metatranscriptomic approaches. Cultivation in batch set-up demonstrated biphasic utilization of propionate, wherein acetate accumulated and underwent oxidation before complete degradation of propionate. Three key species for syntrophic acid degradation were inferred from genomic sequence information and gene expression: a syntrophic propionate-oxidizing bacterium (SPOB) " Syntrophopropionicum ammoniitolerans", a syntrophic acetate-oxidizing bacterium (SAOB) and a novel hydrogenotrophic methanogen, for which we propose the provisional name " Methanoculleus ammoniitolerans". The results revealed consistent transcriptional profiles of the SAOB and the methanogen both during propionate and acetate oxidation, regardless of the presence of an active propionate oxidizer. Gene expression indicated versatile capabilities of the two syntrophic bacteria, utilizing both molecular hydrogen and formate as an outlet for reducing equivalents formed during acid oxidation, while conserving energy through build-up of sodium/proton motive force. The methanogen used hydrogen and formate as electron sources. Furthermore, results of the present study provided a framework for future research into ammonia tolerance, mobility, aggregate formation and interspecies cooperation.
PubMed: 38933034
DOI: 10.3389/fmicb.2024.1389257 -
Sensors (Basel, Switzerland) Jun 2024In recent years, there has been a growing interest in developing portable and personal devices for measuring air quality and surrounding pollutants, partly due to the...
In recent years, there has been a growing interest in developing portable and personal devices for measuring air quality and surrounding pollutants, partly due to the need for ventilation in the aftermath of COVID-19 situation. Moreover, the monitoring of hazardous chemical agents is a focus for ensuring compliance with safety standards and is an indispensable component in safeguarding human welfare. Air quality measurement is conducted by public institutions with high precision but costly equipment, which requires constant calibration and maintenance by highly qualified personnel for its proper operation. Such devices, used as reference stations, have a low spatial resolution since, due to their high cost, they are usually located in a few fixed places in the city or region to be studied. However, they also have a low temporal resolution, providing few samples per hour. To overcome these drawbacks and to provide people with personalized and up-to-date air quality information, a personal device (smartwatch) based on MEMS gas sensors has been developed. The methodology followed to validate the performance of the prototype was as follows: firstly, the detection capability was tested by measuring carbon dioxide and methane at different concentrations, resulting in low detection limits; secondly, several experiments were performed to test the discrimination capability against gases such as toluene, xylene, and ethylbenzene. principal component analysis of the data showed good separation and discrimination between the gases measured.
Topics: Environmental Monitoring; Humans; COVID-19; Carbon Dioxide; Air Pollutants; Air Pollution; Gases; SARS-CoV-2; Methane
PubMed: 38931591
DOI: 10.3390/s24123808 -
Molecules (Basel, Switzerland) Jun 2024Ni-based catalysts have been widely used for the CO reforming of methane (CRM) process, but deactivation is their main problem. This study created an alternative...
Ni-based catalysts have been widely used for the CO reforming of methane (CRM) process, but deactivation is their main problem. This study created an alternative electronic Ni-NiO-CeO interaction on the surface of 5 wt% Ni-5 wt% CeO/AlO-MgO (5Ni5Ce(xh)/MA) catalysts to enhance catalytic potential simultaneously with coke resistance for the CRM process. The Ni-NiO-CeO network was developed on AlO-MgO through layered double hydroxide synthesis via our ammonia vapor diffusion impregnation method. The physical properties of the fresh catalysts were analyzed employing FESEM, N physisorption, and XRD. The chemical properties on the catalyst surface were analyzed employing H-TPR, XPS, H-TPD, CO-TPD, and O-TPD. The CRM performances of reduced catalysts were evaluated at 600 °C under ambient pressure. Carbon deposits on spent catalysts were determined quantitatively and qualitatively by TPO, FESEM, and XRD. Compared to 5 wt% Ni-5 wt% CeO/AlO-MgO prepared by the traditional impregnation method, the electronic interaction of the Ni-NiO-CeO network with the AlO-MgO support was constructed along the time of ammonia diffusion treatment. The electronic interaction in the Ni-NiO-CeO nanostructure of the treated catalyst develops surface hydroxyl sites with an efficient pathway of OH* and O* transfer that improves catalytic activities and coke oxidation.
PubMed: 38930868
DOI: 10.3390/molecules29122803 -
Molecules (Basel, Switzerland) Jun 2024Efficient separation of CH from N is essential for the purification of methane from nitrogen. In order to address this problem, composite materials consisting of...
Efficient separation of CH from N is essential for the purification of methane from nitrogen. In order to address this problem, composite materials consisting of rod-shaped SBA-15-based UiO-66-Br were synthesized for the purpose of separating a CH/N mixture. The materials were characterized via PXRD, N adsorption-desorption, SEM, TEM, FT-IR, and TGA. The adsorption isotherms of CH and N under standard pressure conditions for the composites were determined and subsequently compared. The study revealed that the composites were formed through the growth of MOF nanocrystals on the surfaces of the SBA-15 matrix. The enhancements in surface area and adsorption capacity of hybrid materials were attributed to the structural modifications resulting from the interactions between surface silanol groups and metal centers. The selectivity of the composites towards a gas mixture of CH and N was assessed utilizing the Langmuir adsorption equation. The results of the analysis revealed that the U6B2S5/SBA-15 sample exhibited the greatest selectivity for CH/N adsorption compared to the other samples, with an adsorption selectivity parameter () of 20.06. Additional research is necessary to enhance the enrichment of methane from CH/N mixtures using SBA-15-based metal-organic framework materials.
PubMed: 38930815
DOI: 10.3390/molecules29122750 -
Microorganisms May 2024This study extensively analyzed the bacterial information of biofilms and activated sludge in oxic reactors of full-scale moving bed biofilm reactor-integrated...
This study extensively analyzed the bacterial information of biofilms and activated sludge in oxic reactors of full-scale moving bed biofilm reactor-integrated fixed-film activated sludge (MBBR-IFAS) systems. The bacterial communities of biofilms and activated sludge differed statistically (R = 0.624, < 0.01). The denitrifying genera , , , and were more abundant in activated sludge ( < 0.05), while comammox was more abundant in biofilms ( < 0.05), with an average relative abundance of 8.13%. and had weak co-occurrence relationships with other genera in the MBBR-IFAS systems. Potential function analysis revealed no differences in pathways at levels 1 and 2 based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) between biofilms and activated sludge. However, in terms of pathways at level 3, biofilms had more potential in 26 pathways, including various organic biodegradation and membrane and signal transportation pathways. In comparison, activated sludge had more potential in only five pathways, including glycan biosynthesis and metabolism. With respect to nitrogen metabolism, biofilms had greater potential for nitrification (ammonia oxidation) (M00528), and complete nitrification (comammox) (M00804) concretely accounted for methane/ammonia monooxygenase (K10944, K10945, and K10946) and hydroxylamine dehydrogenase (K10535). This study provides a theoretical basis for MBBR-IFAS systems from the perspective of microorganisms.
PubMed: 38930504
DOI: 10.3390/microorganisms12061121 -
Microorganisms May 2024This study used next-generation sequencing to assess the impact of combined capric acid (C10) and lauric acid (C12) on the ruminal bacterial composition. Eight Holstein...
This study used next-generation sequencing to assess the impact of combined capric acid (C10) and lauric acid (C12) on the ruminal bacterial composition. Eight Holstein cows were randomly assigned to two groups using a cross-over design. The cows were fed two silage-based diets with the addition of either 100 g of stearic acid per cow per day (control), or 50 g of capric acid and 50 g of lauric acid per cow per day (C10 + C12). On day 18, 250 mL of rumen fluid was collected from each cow, and DNA was isolated, amplified, and sequenced. Treatment did not alter bacterial diversity indices, the relative abundance of archaea, nor the fiber-degrading microorganisms, except for a decrease in (from 2.9% to 0.7%; = 0.04). The relative abundance of decreased (from 39.9% to 29.6%; = 0.009), which is notable because some members help to efficiently utilize ammonia by releasing it slowly into the rumen. Furthermore, the relative abundance of increased (from 28.4% to 41.5%; = 0.008), which may have aided the increased ammonia-nitrogen levels in the rumen, as this class contains hyperammonia-producing members. Our study reveals alterations in bacterial abundances with implications for rumen ammonia levels, offering insights into potential strategies for modulating rumen fermentation processes and methane production in ruminant livestock.
PubMed: 38930467
DOI: 10.3390/microorganisms12061085 -
Microorganisms May 2024Although root (AMR) has been noted as an ingredient in ruminant feed, the impacts of AMR feeding on rumen fermentation and the microbial community structure within the...
Although root (AMR) has been noted as an ingredient in ruminant feed, the impacts of AMR feeding on rumen fermentation and the microbial community structure within the rumen are yet to be evaluated. This study investigated the effects of AMR supplementation on rumen fermentation characteristics and microbial community structures in goats. In two sets of feeding experiments, four Japanese native goats were fed AMR (10 g/kg DM/day/head) for three weeks per experiment. The rumen fluid samples were analyzed using high-performance liquid chromatography for fermentation products and next-generation sequencing for microbial analysis. The rumen fluid samples in the second experiment were also subject to an in vitro anaerobic fermentation test. The results indicated a significant modification, with a higher volatile fatty acid (VFA) content in the rumen fluid of goats in the feeding period than before feeding ( < 0.01). The microbial analysis revealed a significant increase in community diversity ( < 0.05) following AMR feeding, and the rumen bacterial community increased in two families belonging to the order Oscillospirales in Firmicutes ( < 0.05). The phylum Verrucomicrobiota was observed to be significantly less abundant after AMR feeding than during the control period ( < 0.05). Notably, the linear discriminant analysis revealed that the families with largely unknown functions in the rumen (Oscillospiraceae, Rikenellaceae, Muribaculaceae, and vadinBB97) were the determinants of the community split between control and AMR feeding. Increased fermentation rate by AMR feeding was also supported by an in vitro culture experiment, which resulted in faster VFA production without affecting methane production in total gas production. The study demonstrated that AMR can significantly facilitate change in the bacterial community structure in the goat rumen involving a shift of the favoring fibrolytic bacteria towards VFA production. The long-term effects of AMR supplementation and its applicability across different ruminant species, with potential benefits for animal health and productivity, should be addressed.
PubMed: 38930452
DOI: 10.3390/microorganisms12061067 -
Animals : An Open Access Journal From... Jun 20243-nitropropionic acid (3NPA) has been proposed as an useful modifier to mitigate ruminal enteric methane emissions. However, few studies investigated the effects of 3NPA...
3-nitropropionic acid (3NPA) has been proposed as an useful modifier to mitigate ruminal enteric methane emissions. However, few studies investigated the effects of 3NPA on ruminal fermentation characteristics of grazing ruminants in vitro. Rumen fluid from grazing yak and cattle were collected and incubated with additions of 0, 8, and 16 mM 3NPA. The total gas production, CH production, and dry matter digestibility significantly decreased with increasing 3NPA doses in both ruminant species ( < 0.05) and methane production decreased to almost 100% in cattle at 8 mM NPA but not yak, while H accumulation showed an opposite trend. The total fatty acid (TVFA) production, acetate concentration, and propionate concentration in cattle decreased as 3NPA doses increased at 12 and 24 h incubation. For yak, the H accumulation reached its apex at 8 mM NPA ( < 0.05). The TVFA in yak decreased significantly with increasing 3NPA doses at 12 and 72 h incubation. Moreover, the acetate concentration and propionate concentration in yak decreased as 3NPA doses increased at 12 and 24 h incubation. Overall, these findings demonstrated that 3NPA could be used as a strategy to mitigate methane emissions; although, it negatively affected the dry matter degradability in vitro.
PubMed: 38929423
DOI: 10.3390/ani14121804 -
Animals : An Open Access Journal From... Jun 2024A deeper understanding of gas emissions in milk production is crucial for promoting productive efficiency, sustainable resource use, and animal welfare. This paper aims... (Review)
Review
A deeper understanding of gas emissions in milk production is crucial for promoting productive efficiency, sustainable resource use, and animal welfare. This paper aims to analyze ammonia and greenhouse gas emissions in dairy farming using bibliometric methods. A total of 187 English-language articles with experimental data from the Scopus and Web of Science databases (January 1987 to April 2024) were reviewed. Publications notably increased from 1997, with the highest number of papers published in 2022. Research mainly focuses on ammonia and methane emissions, including quantification, volatilization, and mitigation strategies. Other gases like carbon dioxide, nitrous oxide, and hydrogen sulfide were also studied. Key institutions include the University of California-Davis and Aarhus University. Bibliometric analysis revealed research evolution, identifying trends, gaps, and future research opportunities. This bibliometric analysis offers insights into emissions, air quality, sustainability, and animal welfare in dairy farming, highlighting areas for innovative mitigation strategies to enhance production sustainability. This research contributes to academia, enhancing agricultural practices, and informing environmental policies. It is possible to conclude that this research is a valuable tool for understanding the evolution of research on gas emissions in dairy cattle facilities, providing guidance for future studies and interventions to promote more sustainable production.
PubMed: 38929340
DOI: 10.3390/ani14121721