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1.
Sci Total Environ ; 923: 171346, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38438039

RESUMO

As a novel agricultural practice, the reuse of food waste compost and digestate as fertilizers leads to a circular economy, but inevitably introduces bio-contaminants such as antibiotic resistance genes (ARGs) into the agroecosystem. Moreover, heavy metal and antibiotic contamination in farmland soil may exert selective pressures on the evolution of ARGs, posing threats to human health. This study investigated the fate, influencing mechanisms and potential risks of ARGs in a soil-vegetable system under different food waste fertilization and remediation treatments and soil contamination conditions. Application of food waste fertilizers significantly promoted the pakchoi growth, but resulted in the spread of ARGs from fertilizers to pakchoi. A total of 56, 80, 84, 41, and 73 ARGs, mobile genetic elements (MGEs) and metal resistance genes (MRGs) were detected in the rhizosphere soil (RS), bulk soil (BS), control soil (CS), root endophytes (RE), and leaf endophytes (LE), respectively. Notably, 7 genes were shared in the above five subgroups, indicating a specific soil-root-endophytes transmission pathway. 36 genes were uniquely detected in the LE, which may originate from airborne ARGs. The combined application of biochar and fertilizers reduced the occurrence of ARGs and MGEs to some extent, showing the remediation effect of biochar. The average abundance of ARGs in the RS, BS and CS was 3.15 × 10-2, 1.31 × 10-2 and 2.35 × 10-1, respectively. Rhizosphere effects may reduce the abundance of ARGs in soil. The distribution pattern of ARGs was influenced by the types of soil, endophyte and contaminant. MGEs is the key driver shaping ARGs dynamics. Soil properties and pakchoi growth status may affect the bacterial composition, and consequently regulate ARGs fate, while endophytic ARGs were more impacted by biotic factors. Moreover, the average daily doses of ARGs from pakchoi consumption is 107-109 copies/d/kg, and its potential health risks should be emphasized.


Assuntos
Carvão Vegetal , Compostagem , Eliminação de Resíduos , Humanos , Antibacterianos/análise , Solo , Genes Bacterianos , Fertilizantes/análise , Verduras , Esterco/microbiologia , Microbiologia do Solo
2.
Sci Total Environ ; 923: 171460, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38442764

RESUMO

This study investigated the impact of adding enzyme inducer (MnSO4) on humic substance (HS) formation during straw composting. The results demonstrated that both enzyme inducer treatment group (Mn) and functional microorganism treatment group (F) led to an increase in the content of HS compared to the treatment group without enzyme inducer and functional microorganism (CK). Interestingly, the enzyme inducer exhibited a higher promoting effect on HS (57.80 % ~ 58.58 %) than functional microbial (46.54 %). This was because enzyme inducer stimulated the growth of key microorganisms and changed the interaction relationship between microorganisms. The structural equation model suggested that the enzyme inducer promoted the utilization of amino acids by the fungus and facilitated the conversion of precursors to humic substance components. These findings provided a direction for improving the quality of composting products from agricultural straw waste. It also provided theoretical support for adding MnSO4 to compost.


Assuntos
Compostagem , Oryza , Substâncias Húmicas/análise , Solo , Aminoácidos , Esterco
3.
Chemosphere ; 353: 141657, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38452978

RESUMO

In order to explore the effects of micro-nano bubble water (MNBW) on compost maturation and the microbial community in cow manure and straw during aerobic composting, we conducted composting tests using tap water with 12 mg/L (O12), 15 mg/L (O15), 18 mg/L (O18), and 21 mg/L (O21) dissolved oxygen in MNBW, as well as tap water with 9 mg/L dissolved oxygen as a control (CK). The results showed that O21 increased the maximum compost temperature to 64 °C, which was higher than the other treatments. All treatments met the harmless standards for compost. The seed germination index (GI) was largest under O21 and 15.1% higher than that under CK, and the non-toxic compost degree was higher. Redundancy analysis showed that the temperature, C/N, pH, and GI were important factors that affected the microbial community composition. The temperature, C/N, and pH were significantly positively correlated with Firmicutes and Actinobacteria (p < 0.05). Firmicutes was the dominant phylum in the mesophilic stage (2-6 days) and it accounted for a large proportion under O21, where the strong thermophilic metabolism increased the production of heat and prolonged the high temperature period. The bacterial genus Ammoniibacillus in Firmicutes accounted for a large proportion under O21 and it accelerated the decomposition of substrates. Therefore, the addition of MNBW changed the microbial community to affect the maturation of the compost, and the quality of the compost was higher under O21.


Assuntos
Compostagem , Microbiota , Animais , Bovinos , Feminino , Nitrogênio/análise , Bactérias/metabolismo , Firmicutes , Esterco/microbiologia , Oxigênio , Solo
4.
Sci Total Environ ; 923: 171548, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38458466

RESUMO

The aim is to enhance lignin humification by promoting laccase activities which can promote lignin depolymerization and reaggregation during composting. 1-Hydroxybenzotriazole (HBT) is employed to conduct laccase mediator system (LMS), application of oxidized graphene (GO) in combination to strengthen LMS. Compared with control, the addition of GO, HBT, and GH (GO coupled with HBT) significantly improved laccase expression and activities (P < 0.05), with lignin humification efficiency also increased by 68.6 %, 36.7 %, and 107.8 %. GH treatment induces microbial expression of laccase by increasing the abundance and synergy of core microbes. The unsupervised learning model, vector autoregressive model and Mantel test function were combined to elucidate the mechanism of action of exogenous materials. The results showed that GO stabilized the composting environment on the one hand, and acted as a support vector to stabilize the LMS and promote the function of laccase on the other. In GH treatment, degradation of macromolecules and humification of small molecules were promoted simultaneously by activating the dual function of laccase. Additionally, it also reveals the GH enhances the humification of lignocellulosic compost by converting phenolic pollutants into aggregates. These findings provide a new way to enhance the dual function of laccase and promote lignin humification during composting. It could effectively achieve the resource utilization of organic solid waste and reduce composting pollution.


Assuntos
Compostagem , Substâncias Húmicas , Substâncias Húmicas/análise , Solo , Lacase/metabolismo , Lignina/metabolismo , Biomassa , Esterco
5.
Parasitol Res ; 123(3): 157, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459281

RESUMO

Musca domestica Linnaeus is a devastating insect pest of medical and veterinary importance with reports of resistance development to commonly used insecticides worldwide. Rearing substrates usually play a crucial role in determining susceptibility to insecticides and control of insect pests. The aim of the present study was to investigate the effect of five rearing substrates of M. domestica on its susceptibility to different insecticides and activities of metabolic enzymes. After 30 generations of rearing, susceptibility of M. domestica to tested insecticides, viz., malathion, pirimiphos-methyl, alpha-cypermethrin, deltamethrin, methomyl, propoxur, spinetoram, and chlorfenapyr had evident differences. Musca domestica reared on hen liver exhibited reduced susceptibility to all insecticides followed by the strain reared on poultry manure. However, M. domestica reared on milk-based diet showed the highest susceptibility to tested insecticides followed by the strain reared on manures of buffalo and horse. In addition, M. domestica reared on different substrates exhibited significant differences (p < 0.01) in the activities of glutathione S-transferase (GST), cytochrome P450-dependent monooxygenase, and carboxylesterase (CarE). Overall, hen liver and poultry manure strains exhibited higher activities of metabolic enzymes than those of the milk-based diet, buffalo, and horse manure strains. In conclusion, the data of the present study exhibited a significant effect of rearing substrates on the susceptibility to insecticides and activities of metabolic enzymes in M. domestica. These results could be helpful for the sustainable management of M. domestica on different hosts by selecting appropriate insecticides.


Assuntos
Moscas Domésticas , Inseticidas , Animais , Feminino , Cavalos , Inseticidas/farmacologia , Esterco , Búfalos , Galinhas , Resistência a Inseticidas
6.
Sci Rep ; 14(1): 5126, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429337

RESUMO

The utilization of biochar's as soil amendments for enhancing nutrient retention in subsoils present potential limitations. To address this issue, we conducted a greenhouse experiment to assess the effects of various biochar's derived from animal manures (swine manure, poultry litter, cattle manure) and plant residues (rice straw, soybean straw, corn straw) when applied to surface of an acidic soil. Our study focused on wheat crops under a no-tillage system, with a subsequent evaluation of the residual impacts on soybeans. The experimental design involved the application of biochar's at different rates i.e. 10 and 20 Mg ha-1, followed by the assessment of their influence on NPK levels, pH, and exchangeable Al in stratified soil layers (0-5, 5-10, 10-15, and 15-25 cm). Furthermore, we investigated the interplay between biochar doses and the application of nitrogen (N) in the top 5 cm of soil, specifically examining NO 3 - , NH 4 + , P and K levels. Our findings revealed that in the top 5 cm of soil, biochar doses and N application significantly affected NO 3 - , NH 4 + , P and K concentrations. However, in deeper soil layers, no significant differences were observed among biochar doses with or without N application. Interestingly, K levels were impacted throughout all soil depths, regardless of the presence or absence of N application. Moreover, biochar application up to a 5 cm depth induced favorable changes in soil pH and reduced exchangeable Al. In contrast, deeper layers experienced a decrease in soil pH and an increase in exchangeable Al following biochar treatment. In conclusion, our study demonstrates that biochar's can effectively retain NPK nutrients, enhance soil pH, and decrease exchangeable Al, independent of the type and dosage of application under a no-tillage system. Nonetheless, the efficacy of biochar amendments may vary with soil depth and type of nutrient, warranting careful consideration for maximizing their benefits in sustainable agricultural practices.


Assuntos
Carvão Vegetal , Esterco , Animais , Bovinos , Suínos , Carvão Vegetal/química , Solo/química , Nutrientes
7.
Environ Geochem Health ; 46(4): 123, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483669

RESUMO

Soil is one of the largest reservoirs of microbial diversity in nature. Although soil management is vital for agricultural purposes, intensive practices can have a significant impact on fertility, microbial community, and resistome. Thus, the aim of this study was to evaluate the effects of an intensive soil management system on the chemical attributes, composition and structure of prevalent bacterial communities, and presence and abundance of antimicrobial resistance genes (ARGs). The chemical characterization, bacterial diversity and relative abundance of ARGs were evaluated in soils from areas of intensive vegetable cultivation and forests. Results indicate that levels of nutrients and heavy metals were higher in soil samples from cultivated areas. Similarly, greater enrichment and diversity of bacterial genera was detected in agricultural areas. Of the 18 target ARGs evaluated, seven were detected in studied soils. The oprD gene exhibited the highest abundance among the studied genes and was the only one that showed a significantly different prevalence between areas. The oprD gene was identified only from soil of the cultivated areas. The blaSFO, erm(36), oprD and van genes, in addition to the pH, showed greater correlation with in soil of cultivated areas, which in turn exhibited higher contents of nutrients. Thus, in addition to changes in chemical attributes and in the microbial community of the soil, intensive agricultural cultivation systems cause a modification of its resistome, reinforcing the importance of the study of antimicrobial resistance in a One Health approach.


Assuntos
Antibacterianos , Microbiota , Antibacterianos/farmacologia , Solo/química , Genes Bacterianos , Brasil , Bactérias , Resistência Microbiana a Medicamentos/genética , Microbiota/genética , Florestas , Microbiologia do Solo , Esterco/microbiologia
8.
Bioresour Technol ; 398: 130503, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442847

RESUMO

Targeted regulation of composting to convert organic matter into humic acid (HA) holds significant importance in compost quality. Owing to its low carbon content, chicken manure compost often requires carbon supplements to promote the humification progress. The addition of lignite can increase HA content through biotic pathways, however, its structure was not explored. The Parallel factor analysis revealed that lignite can significantly increase the complexity of highly humified components. The lignite addition improved phenol oxidase activity, particularly laccase, during the thermophilic and cooling phases. The abundance and transformation functions of core bacteria also indicated that lignite addition can influence the activity of microbial transformation of HA components. The structural equation model further confirmed that lignite addition had a direct and indirect impact on enhancing the complexity of HA components through core bacteria and phenol oxidase. Therefore, lignite addition can improve HA structure complexity during composting through biotic pathways.


Assuntos
Compostagem , Substâncias Húmicas , Animais , Substâncias Húmicas/análise , Solo , Esterco , Galinhas , Carvão Mineral , Monofenol Mono-Oxigenase , Carbono
9.
J Environ Manage ; 355: 120463, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38430882

RESUMO

Biochar could promote humification in composting, nevertheless, its mechanism has not been fully explored from the perspective of the overall bacterial community and its metabolism. This study investigated the effects of bamboo charcoal (BC) and wheat straw biochar (WSB) on the humic acid (HA) and fulvic acid (FA) contents during pig manure composting. The results showed that BC enhanced humification more than WSB, and significantly increased the HA content and HA/FA ratio. The bacterial community structure under BC differed from those under the other treatments, and BC increased the abundance of bacteria associated with the transformation of organic matter compared with the other treatments. Furthermore, biochar enhanced the metabolism of carbohydrates and amino acids in the thermophilic and cooling phases, especially BC. Through Mantel tests and network analysis, we found that HA was mainly related to carbon source metabolism and the bacterial community, and BC might change the interaction patterns among carbohydrates, amino acid metabolism, Bacillales, Clostridiales, and Lactobacillales with HA and FA to improve the humification process during composting. These results are important for understanding the mechanisms associated with the effects of biochar on humification during composting.


Assuntos
Carvão Vegetal , Compostagem , Animais , Suínos , Carvão Vegetal/química , Esterco/microbiologia , Solo/química , Substâncias Húmicas , Carboidratos , Bactérias
10.
J Environ Manage ; 355: 120475, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38447511

RESUMO

The production of biogas from organic waste has attracted considerable interest as a solution to current energy and waste management challenges. This study explored the methane (CH4) production potential of swine manure (SM), food waste (FW), and tomato waste (TW) and the changes in the microbial community involved in the anaerobic digestion process. The results revealed that the CH4 production potentials of the four kinds of SM samples were influenced by the characteristics of SM (e.g., age and storage period). Among the four kinds of SM samples, the CH4 yield from the manure directly sampled from primiparous sows (SM3) was the highest. The CH4 yield was significantly improved when SM3 was co-digested with FW, but not with TW. The addition of SM fostered a stable CH4 production community by enhancing the interaction between methanogens and syntrophic bacteria. Furthermore, the addition of FW as a co-substrate may improve the functional redundancy structure of the methanogenesis-associated network. Overall, the characteristics of SM must be considered to achieve consistent CH4 yield efficiency from anaerobic digestion since CH4 production potentials of SM can be different. Also, the contribution of co-substrate to the synergistic relationship between methanogens and syntrophic bacteria can be considered when a co-substrate is selected in order to enhace CH4 yield from SM.


Assuntos
Eliminação de Resíduos , Animais , Suínos , Feminino , Anaerobiose , Reatores Biológicos , Esterco/microbiologia , Alimentos , Metano , Biocombustíveis/análise , Bactérias , Digestão
11.
Waste Manag ; 178: 311-320, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38428381

RESUMO

Animal slurry storage is an important ammonia (NH3) emission source. Sulfuric acid (H2SO4)-modified vermiculite coverage is a new promising technology for controlling NH3 emission from slurry storage. However, the underlying mechanisms in controlling the mitigation effect remain unclear. Here, a series of experiments to determine the effect of H2SO4 on the modified vermiculite properties, floating persistence, and NH3 mitigation effect was conducted. Results showed that abundant H2SO4 and sulfate remained on the outer surface and in the extended inner pores of the vermiculite with acidifying H+ concentrations higher than 5 M. An initial strong instantaneous acidification of surface slurry released rich carbon dioxide bubbles, strengthening cover floating performance. An acidification in the vermiculite cover layer and a good coverage inhibition interacted, being the two leading mechanisms for mitigating NH3 during initial 40-50 days of storage. The bacterial-amoA gene dominated the conversion of NH3 to nitrous oxide after 50 days of storage. Vermiculite with 5 M H+ modification reduced the NH3 emissions by 90 % within the first month of slurry storage and achieved a 64 % mitigation efficiency throughout the 84 days period. With the development of the aerial spraying equipment such as agricultural drones, acidifying vermiculite coverage hold promise as an effective method for reducing NH3 emission while absorbing nutrients from liquid slurry storage tank or lagoon. This design should now be tested under field conditions.


Assuntos
Silicatos de Alumínio , Amônia , Ácidos Sulfúricos , Animais , Amônia/análise , Agricultura , Esterco , Óxido Nitroso/análise
12.
Braz J Biol ; 84: e276160, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38511773

RESUMO

Studies have underscored a growingdemand for innovative practices in the cultivation of seedlings from forest species, with a notable emphasis on the utilization of organic waste, inoculation with arbuscular mycorrhizal fungi (AMF), and phosphate fertilization. This study aimed to evaluate the impact of organic residues, inoculation with AMF, and phosphorus on the growth and quality of Peltophorum dubium (Spreng.) Taub. seedlings. Two independent experiments were conducted. In Experiment I, treatments included inoculation with various AMF species: control (without inoculation), Clareoideoglomus etunicatum, Rhizophagus heterosporum, Rhizophagus clarum, and MIX (a combination of the three AMF species), all in conjunction with varying doses of phosphorus (0, 60, 120, 180, and 240 mg kg-1 soil). In Experiment II, treatments comprised a control group (without AMF) and inoculation with Glomus clarum, Gigaspora margarita, Gigaspora albida, Clareoideoglomus etunicatum, and MIX (a combination of the four AMF species), each associated with four substrates: S1) soil + coarse sand - SCS, S2) SCS + poultry manure, S3) SCS + cattle manure, and S4) SCS + sheep manure. Peltophorum dubium seedlings exhibited heightened growth with the inoculation of R. heterosporum, R. clarum, and MIX. Positive responses were observed in seedlings when exposed to organic residues, particularly sheep manure, resulting in increased biomass production and enhanced Dickson quality index. The AMF inoculation, specifically with R. heterosporum, R. clarum, and MIX, provided optimal growth conditions for P. dubium seedlings. Remarkably, the utilization of organic residues, notably substrates with chicken manure and cattle manure, exerted substantial positive effects on both growth and quality of P. dubium seedlings.


Assuntos
Micorrizas , Animais , Bovinos , Ovinos , Micorrizas/fisiologia , Plântula , Raízes de Plantas , Fósforo , Esterco , Solo
13.
Huan Jing Ke Xue ; 45(3): 1840-1848, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471895

RESUMO

Animal farms are important sources of microbial contamination in the air environment. However, there are few reports on the time-regularity characteristics of airborne microbial contamination in farms. In the context of this situation, a study was conducted for more than 80 weeks using 16S rRNA gene amplicon sequencing to characterize the bacterial distribution and respiratory exposure in the farm air and fecal environment, respectively, taking a layer farm as an example. The results showed that 16S rRNA concentrations in air and manure samples ranged from 6.08×105-4.90×106 copies·m-3 and 4.27×108-1.15×1010 copies·g-1, respectively. The mean values of airborne bacterial concentrations were significantly higher in winter than in summer, whereas the biodiversity showed the opposite trend. The dominant bacterial phylum in both air and manure in the layer farm was Firmicutes. During the investigated time, the top three dominant genera in the air were relatively stable, in the order of Lactobacillus, Bacteroides, and Faecalibacterium, whereas the dominant genera in feces fluctuated with the increase in breeding time. The correlation between the community structure of bacteria and pathogenic bacteria in both air and manure was not significant, but the concentrations of both target microorganisms in different media were significantly correlated. The bioaerosolization index of bacteria in manure showed an increasing trend with increasing breeding time, whereas the opposite trend was observed for pathogenic bacteria. In this case, [Ruminococcus]_torques_group, Bacteroides, and Faecalibacterium were the top three pathogenic genera that were the most prone to aerosolization. There were seasonal differences in bacterial respiratory exposures of chicken farm workers, with mean intake values of 2.54×107 copies·d-1 and 2.87×105 copies·d-1 for bacteria and pathogenic bacteria, respectively. The results of this study will provide a scientific basis for systematically assessing the contamination characteristics and potential health risks of airborne microorganisms on farms and for developing corresponding industry standards for occupational exposure and prevention and control measures.


Assuntos
Galinhas , Esterco , Animais , Fazendas , Galinhas/genética , Esterco/microbiologia , RNA Ribossômico 16S/genética , Bactérias/genética , Microbiologia do Ar
14.
Environ Monit Assess ; 196(4): 355, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466496

RESUMO

Vermicompost is a substantial source of nutrients, promotes soil fertility, and maintains or increases soil organic matter levels. Potentially toxic elements (PTEs) in vermicompost impact on nitrification activity. However, it is yet unknown how vermicompost affects nitrifying bacteria and archaea, comammox Nitrospira inopinata (complete ammonia oxidizers), net nitrification rates (NNRs), and PTEs. The effects of vermicompost application on NNRs, potential nitrification rates (NPs), PTEs, and the abundances of comammox N. inopinata bacteria, nitrite-oxidizing bacteria (NOB), and ammonia-oxidizing bacteria (AOB)/archaea (AOA) were studied. NNRs and NPs were significantly higher (p < 0.05) in fresh cow-dung vermicompost (stored for 40 days) as compared with other organic manure. The level of PTEs (Cu2+, Fe2+, Pb2+, Cd2+, and Zn2+) was significantly lower (p < 0.05) in vermicompost as compared with compost of waste material with Trichoderma and cow dung. Comammox N. inopinata, NOB, AOB, and AOA were significantly higher (p < 0.05) in stored cow-dung vermicompost (more than 1 year) as compared with other organic manure. The results of the scatterplot matrix analysis suggested that Fe2+, total nitrogen (TN), soil organic carbon (SOC), and total carbon (TC) were linearly correlated (p < 0.001) with NNRs and NPs in vermicompost and organic manure. Similarly, comammox N. inopinata bacteria, NOB, AOB, and AOA were linearly correlated (p < 0.001) with NNR and NP. These results indicated that vermicompost promoted nitrification activity by increasing microbial diversity and abundance, supplying nutrients and organic matter for microbial growth, and facilitating complex microbial interactions. It may be concluded that the influence of vermicompost, which played a great role in PTE concentration reduction, increased chemical, and biological properties, increased the growth rate of nitrifying bacteria/archaea and the nitrogen cycle.


Assuntos
Archaea , Nitrificação , Esterco , Amônia , Carbono , Oxirredução , Solo/química , Filogenia , Microbiologia do Solo , Monitoramento Ambiental , Bactérias , Nitritos
15.
Sci Rep ; 14(1): 5856, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467697

RESUMO

Combined application of organic and mineral fertilizers is crucial to obtaining high crop yields, increasing the utilization of nutrients by plants, and limiting their dispersion, thus protecting the environment, which underscores the importance of sustainable and minimally invasive agriculture. The aim of the field experiment was to determine the effect of application of rabbit manure (RM) and mineral nitrogen (Nmin) on the dry matter (DM) yield of maize and on nitrogen content, uptake, and use efficiency (NUE). RM application was tested at levels of 0, 20, 40 and 60 t·ha-1, and Nmin application at 0, 50, 100 and 150 kg·ha-1. Significant differences were noted in yield and in the content and uptake of nitrogen depending on both experimental factors. Increasing the application of RM and Nmin led to an increase in the yield of harvested maize and in the content and uptake of nitrogen. In terms of DM yield and nitrogen uptake (yield of crude protein), the most beneficial fertilizer variant was 60 t·ha-1 RM applied together with 100 kg·ha-1 Nmin. The highest NUE value was obtained following application of 20 t·ha-1 RM together with 150 kg·ha-1 Nmin.


Assuntos
Esterco , Solo , Animais , Coelhos , Zea mays , Nitrogênio/análise , Silagem , Agricultura , Minerais , Fertilizantes/análise , Fertilização
16.
Environ Int ; 185: 108499, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38368718

RESUMO

The transportation of antibiotic resistance genes (ARGs) in manure-soil-plant continuums poses risks to human health. Horizontal gene transfer, particularly for bacterial transformation, is an important way for ARG dissemination. As crucial components in soils, iron oxides impacted the fates of various abiotic and biotic contaminants due to their active properties. However, whether they can influence the transformation of ARGs is unknown, which waits to be figured out to boost the assessment and control of ARG spread risks. In this study, we have investigated the effects of goethite, hematite, and magnetite (0-250 mg/L, with sizes < 100 nm and > 100 nm) on the transfer of ampicillin resistance genes to Escherichia coli cells. At lower iron oxide concentrations, the transformation of ARGs was first facilitated (transformation frequency reached up to 3.38-fold higher), but the facilitating effects gradually weakened and eventually disappeared as concentrations further increased. Particle size and iron oxide type were not the universal determinants controlling the transformation. At lower concentrations, iron oxides interacted with proteins and phospholipids in E. coli envelope structures, and induced the overgeneration of intracellular reactive oxygen species. Consequently, they led to pore formation and permeability enhancement on the cell membrane, thus promoting the transformation. The facilitation was also associated with the carrier-like effect of iron oxides for antibiotic resistance plasmids. At higher concentrations, the weakened facilitations were attributed to the aggregation of iron oxides. In this study, we highlight the crucial roles of the concentrations (contents) of iron oxides on the dissemination of ARGs in soils; this study may serve as a reference for ARG pollution control in future agricultural production.


Assuntos
Antibacterianos , Compostos Férricos , Transformação Bacteriana , Humanos , Antibacterianos/farmacologia , Escherichia coli/genética , Genes Bacterianos , Resistência Microbiana a Medicamentos/genética , Solo/química , Óxidos , Ferro , Microbiologia do Solo , Esterco/microbiologia
17.
Sci Total Environ ; 920: 170993, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38369140

RESUMO

This study explores the relationship between poultry farming's antibiotic administration practices and residual antibiotic levels in the litter before its application onto agricultural soils. Twenty-three antibiotics were performed across 19 Argentinean farms representing diverse antibiotic management practices. Analysis revealed up to 20 antibiotics from eight chemical classes in poultry litter samples, with tylosin, enrofloxacin, and salinomycin being the most relevant drugs. Farms with restricted antibiotic use in feed exhibited lower residual concentrations. A self-heating treatment was tested to reduce litter antibiotic levels. Although a 60 % reduction of antibiotics was found after treatment, prevalent compounds persisted at residual levels. Regulatory measures and comprehensive litter treatments pre-application are crucial to mitigate environmental risks. This is the first study that provides insight on the occurrence of >20 drugs in real poultry production scenarios from Latin America and demonstrates how relatively simple treatments can be readily applied to decrease the associated environmental risks.


Assuntos
Antibacterianos , Aves Domésticas , Animais , Antibacterianos/análise , Argentina , Agricultura , Enrofloxacina , Solo/química , Esterco/análise
18.
J Environ Manage ; 354: 120357, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38354611

RESUMO

Fulvic acids (FAs) is formed during the bioconversion of organic matter (OM) to biogas during anaerobic digestion (AD) and has a complex structure and redox function. However, the evolutionary mechanisms of FAs during AD and its interactions with acid and methane production have not been sufficiently investigated, especially at different stages of AD. Intermittent AD experiments by chicken manure and rice husk showed significant structural changes and reduced aromatization of FAs (e.g., O-H stretch6, 14.10-0%; SR, 0.22-0.60). The electron donating capacity (EDC) [9.76-45.39 µmole-/(g C)] and electron accepting capacity (EAC) [2.55-5.20 µmole-/(g C)] of FAs showed a tendency of decreasing and then increasing, and FAs had a stronger electron transfer capacity (ETC) in the methanogenic stage. Correlation analysis showed that the EDC of FAs was influenced by their own structure (C-O stretch2, C-H bend1, C-H bend4, and N-H bend) and also had an inhibitory effect on propionic production, which further inhibited acetic production. The EAC of FAs was affected by molecular weight and had a promoting effect on methane production. Structural equation modelling identified three possible pathways for AD. The C-O stretch2 structure of FAs alone inhibits the production of propionic. In addition, pH can directly affect the EDC of FAs. This study provides a theoretical basis for the structural and functional evolution of FAs in AD of chicken manure on the mechanism of methane production.


Assuntos
Benzopiranos , Reatores Biológicos , Galinhas , Animais , Anaerobiose , Esterco/análise , Metano/análise , Oxirredução , Ácidos Graxos Voláteis/análise , Biocombustíveis/análise
19.
J Environ Manage ; 354: 120328, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38354615

RESUMO

This study aims to evaluate whether different doses of Bacillus-based inoculum inoculated in chicken manure and sawdust composting will provide distinct effects on the co-regulation of ammonia (NH3) and hydrogen sulfide (H2S), nutrient conversions and microbial topological structures. Results indicate that the Bacillus-based inoculum inhibits NH3 emissions mainly by regulating bacterial communities, while promotes H2S emissions by regulating both bacterial and fungal communities. The inoculum only has a little effect on total organic carbon (TOC) and inhibits total sulfur (TS) and total phosphorus (TP) accumulations. Low dose inoculation inhibits total potassium (TK) accumulation, while high dose inoculation promotes TK accumulation and the opposite is true for total nitrogen (TN). The inoculation slightly affects the bacterial compositions, significantly alters the fungal compositions and increases the microbial cooperation, thus influencing the compost substances transformations. The microbial communities promote ammonium nitrogen (NH4+-N), TN, available phosphorus (AP), total potassium (TK) and TS, but inhibit nitrate nitrogen (NO3--N), TP and TK. Additionally, the bacterial communities promote, while the fungal communities inhibit the nitrite nitrogen (NO2--N) production. The core bacterial and fungal genera regulate NH3 and H2S emissions through the secretions of metabolic enzymes and the promoting or inhibiting effects on NH3 and H2S emissions are always opposite. Hence, Bacillus-based inoculum cannot regulate the NH3 and H2S emissions simultaneously.


Assuntos
Bacillus , Compostagem , Microbiota , Animais , Bacillus/metabolismo , Galinhas , Esterco/microbiologia , Odorantes , Amônia/análise , Nitrogênio/análise , Bactérias/metabolismo , Nutrientes , Fósforo , Potássio , Solo/química
20.
J Environ Manage ; 354: 120359, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38359629

RESUMO

Livestock manure is known to be a significant reservoir of antibiotic resistance genes (ARGs), posing a major threat to human health and animal safety. ARGs are found in both intracellular and extracellular DNA fractions. However, there has been no comprehensive analysis of these fractions in commercial organic fertilizers (COFs). The present study conducted a systematic survey of the profiles of intracellular ARGs (iARGs) and extracellular ARGs (eARGs) and their contributing factor in COFs in Northern China. Results showed that the ARG diversity in COFs (i.e., 57 iARGs and 53 eARGs) was significantly lower than that in cow dung (i.e., 68 iARGs and 69 eARGs). The total abundance of iARGs and eARGs decreased by 85.7% and 75.8%, respectively, after compost processing, and there were no significant differences between iARGs and eARGs in COFs (P > 0.05). Notably, the relative abundance of Campilobacterota decreased significantly (99.1-100.0%) after composting, while that of Actinobacteriota and Firmicutes increased by 21.1% and 29.7%, respectively, becoming the dominant bacteria in COFs. Co-occurrence analysis showed that microorganisms and mobile genetic elements (MGEs) were more closely related to eARGs than iARGs in COFs. And structural equation models (SEMs) further verified that microbial community was an essential factor regulating iARGs and eARGs variation in COFs, with a direct influence (λ = 0.74 and 0.62, P < 0.01), following by similar effects of MGEs (λ = 0.59 and 0.43, P < 0.05). These findings indicate the need to separate eARGs and iARGs when assessing the risk of dissemination and during removal management in the environment.


Assuntos
Antibacterianos , Fertilizantes , Animais , Humanos , Antibacterianos/farmacologia , Genes Bacterianos , Resistência Microbiana a Medicamentos/genética , Bactérias/genética , Esterco
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