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1.
PLoS One ; 15(9): e0229880, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32966333

RESUMO

Aerobic composting is a sustainable method for chicken manure recycling, while its unsuitable porosity and carbon to nitrogen ratio (C/N) may result in high nitrogen loss and incomplete composting. With the aim to investigate the effects of carbon-based additives and two ventilation rates on chicken manure composting and microbial community, two series of treatments were set up for chicken manure composting, in order to investigate their effects on the biodegradation process, ammonia (NH3) emission, nitrogen loss, physiochemical properties and microbial community. The results showed that additives and ventilation rates set in the current study influenced the carbon dioxide (CO2) production from the 2nd week and also the physiochemical parameters during the entire process, while no inhibitory effect on the maturity were observed. With woody peat as additive, the NH3 emission amount and nitrogen loss rate were shown as 15.86 mg and 4.02%, less than those in other treatments, 31.08-80.13 mg and 24.26-34.24%, respectively. The high aeration rate increased the NH3 emission and nitrogen loss, which were varied when the additives were different. The terminal restriction fragment length polymorphism (T-RFLP) results showed that the additives and the ventilation rates changed the microbial community, while the prominent microbial clones belonged to the class of Bacilli and Clostridia (in the phylum of Firmicutes), and Alphaproteobacteria, Deltaproteobacteria and Gammaproteobacteria (in the phylum of Proteobacteria). Bacillus spp. was observed to be the most dominant bacteria in all the composting stages and treatments. It was concluded that woody peat could improve chicken manure composting more than other additives, especially on reducing nitrogen loss, meanwhile 0.18 L‧min-1‧kg-1 DM was suitable for various additives. Therefore, suitable additive and aeration rate could be used in practical application, which could significantly reduce nitrogen loss without influence on the compos maturity process.


Assuntos
Amônia/metabolismo , Compostagem/métodos , Esterco/microbiologia , Microbiota/fisiologia , Nitrogênio/metabolismo , Amônia/análise , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Carbono/metabolismo , Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Galinhas , DNA Bacteriano/isolamento & purificação , Nitrogênio/análise , Porosidade , Ventilação/métodos
2.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1600-1609, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924358

RESUMO

Adding biological passivation agent during composting is one of the most effective ways to reduce the toxicity of heavy metals in contaminated livestock manure. To further improve biological passivation, we obtained a strain with high-heavy metal compounds tolerance to passivate heavy-metal contaminated manure and to characterize heavy-metal biosorption. High-tolerance microorganisms for lead and cadmium were isolated and screened from swine manure composting samples. The strain was identified by its morphology and molecular biology. After the influence of different pH, temperature and salt concentrations on growth of the strain were investigated, the optimal growth conditions were obtained for further analysis of its biosorption characteristics of lead and cadmium. The bacterium with tolerance to lead and cadmium termed SC19 was obtained, whose lead resistance was 600 mg/L and cadmium resistance was 120 mg/L. The isolate was further identified as Cedecea sp., and then its optimum pH was 7.0, temperature was 37 °C, and salt concentration was 0.5%. Lead removal was highest after 30 min of adsorption by the SC19 strain cultured for the stationary phase 36 h, and the maximum removal rate and biosorption capacity of lead were 60.7% and 329.13 mg/g, respectively. Meanwhile, cadmium removal was highest after 30 min of adsorption by the strain cultured for the logarithmic phase 8 h, and the maximum removal rate and biosorption capacity of cadmium were 51.0% and 126.19 mg/g, respectively. Fourier Transform InfraRed (FT-IR) results revealed that the biosorption process mainly happened on the surface of SC19 cell and many active groups on the cell surface could chelate the Pb²âº and Cd²âº. By comprehensive comparison, it was showed that strain SC19 shared a certain capacity of Pb²âº and Cd²âº biosorption, and the bacterium provided precious microbial germplasm resources for biological passivation of heavy metal contaminated manure.


Assuntos
Cádmio , Resistência a Medicamentos , Enterobacteriaceae , Chumbo , Esterco , Adsorção , Animais , Biodegradação Ambiental , Cádmio/metabolismo , Cádmio/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/metabolismo , Chumbo/metabolismo , Chumbo/farmacologia , Esterco/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos
3.
Ecotoxicol Environ Saf ; 205: 111099, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829207

RESUMO

Soil contamination with metallic nanoparticles is increasing due to their increased use in industrial and domestic settings. These nanoparticles are potentially toxic to soil microbes and may affect their associated functions and thereby the nutrient cycling in agro-ecosystems. This study examined the effects of iron oxides nanoparticles (IONPs) on carbon (C) and nitrogen (N) dynamics of poultry (PM) and farmyard manure (FYM) in the soil. The application of IONPs increased iron content in soil microbial biomass, which reflected its consumption by the microbes. As a result, colony-forming units of bacteria and fungi reduced considerably. Such observations lead to a decrease in CO2 emission from PM and FYM by 27 and 28%, respectively. The respective decrease fractions in the case of N mineralization were 24 and 35%. Consequently, soil mineral N content was reduced by 16% from PM and 12% from FYM as compared to their sole application without IONPs. Spinach dry matter yield and apparent N recovery were increased by the use of organic waste (FYM, PM). The use of IONPs significantly reduced the plant N recovery fraction by 26 and 24% (P < 0.05) from PM and FYM, respectively. All the results mentioned above lead us to conclude that IONPs are toxic to soil microbes and affect their function i.e., carbon and N mineralization of applied manure, and thereby the on-farm N cycling from the manure-soil-plant continuum.


Assuntos
Compostos Férricos/toxicidade , Nanopartículas/toxicidade , Ciclo do Nitrogênio , Animais , Biomassa , Carbono , Ecossistema , Fertilizantes , Esterco/microbiologia , Nitrogênio , Aves Domésticas , Solo , Microbiologia do Solo
4.
Ecotoxicol Environ Saf ; 204: 111129, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805505

RESUMO

Anaerobic digestate has been widely used for agricultural activities as an organic fertilizer product. Dissolved organic matter (DOM) derived from anaerobic digestate plays a key role in the speciation, bioavailability and ultimate fate of metals that is related to agriculture and food safety as well as the soil environment. Hence, the binding properties of Cu, Pb and Zn with digestate DOM are investigated using two-dimensional correlation spectroscopy (2D-COS) in combination with ultraviolet absorption, synchronous fluorescence spectra (SFS) and Fourier transform infrared (FTIR) spectroscopy. The 2D absorption COS shows that the DOM at 200 nm is most susceptive with the addition of Pb, followed by Zn and Cu. The log-transformed absorption spectra can also obtain more valuable signals than that from conventional absorption spectra. The 2D-SFS-COS indicates that protein-like peak is more sensitive to the variation of the concentration of metal ions, and fulvic-like substances can preferentially interact with the three heavy metals (HMs). The 2D-FTIR-COS reveals that Cu(II) and Zn(II) ions can be bonded preferentially to the N-H of secondary amide (II), and phenolic OH groups shows a favorable binding with Pb(II). Humic-like peaks with Cu(II) and Zn(II) obtains relatively higher log KM values than fulvic- and protein-like substances. However, the proportion of initial fluorescence (f) for DOM-Cu(II) and DOM-Zn(II) decreased with an increase in wavelength. Protein-like materials have more fluorescent substances that can combine with Cu(II) and Zn(II). This study provides a guide for understanding the geochemical behavior of metal ions in agricultural soils when anaerobic digestate is applied as an organic fertilizer product.


Assuntos
Substâncias Húmicas/análise , Esterco/microbiologia , Metais Pesados/química , Anaerobiose , Animais , Galinhas , Fertilizantes , Fluorescência , Solo/química , Espectrometria de Fluorescência/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
5.
Artigo em Inglês | MEDLINE | ID: mdl-32630263

RESUMO

The management of cattle manure (CM) has become increasingly challenging because its production continues to rise, while the regulations on manure management have become increasingly stringent. In Korea, most farms produce CM as a dry mixture with lignocellulosic bedding materials (mainly sawdust), making it impractical to treat CM by anaerobic digestion. To address this problem, this study examined whether anaerobic co-digestion with food waste (FW) and pig manure (PM) could be an effective approach for the treatment of CM. The batch anaerobic digestion tests at different CM: FW: PM mixing ratios showed that more methane was produced as the FW fraction increased, and as the CM fraction decreased. The response surface models describing how the substrate mixing ratio affects the methane yield and synergistic effect (methane yield basis) were successfully generated. The models proved that the methane yield and synergistic effect respond differently to changes in the substrate mixing ratio. The maximum 30-day methane yield was predicted at 100% FW, whereas the maximum 30-day synergy index was estimated for the mixture of 47% CM, 6% FW, and 47% PM (total solids basis). The synergy index model showed that CM, FW, and PM could be co-digested without a substantial loss of their methane potential at any mixing ratio (30-day synergy index, 0.89-1.22), and that a possible antagonistic effect could be avoided by keeping the FW proportion less than 50%. The results suggest that co-digestion with PM and FW could be flexibly applied for the treatment and valorization of CM in existing anaerobic digestion plants treating FW and PM.


Assuntos
Alimentos , Esterco/microbiologia , Eliminação de Resíduos , Anaerobiose , Animais , Biocombustíveis , Reatores Biológicos , Bovinos , Metano , República da Coreia , Suínos
6.
PLoS One ; 15(4): e0225873, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32352968

RESUMO

Black soldier fly (BSF; Hermetia illucens L.) larvae can convert fresh pig manure into protein and fat-rich biomass, which can then be used as aquafeed for select species. Currently, BSF is the only approved insect for such purposes in Canada, USA, and the European Union. Pig manure could serve as a feed substrate for BSF; however, it is contaminated with zoonotic pathogens (e.g., Staphylococcus aureus and Salmonella spp.). Fortunately, BSF larvae inhibit many of these zoonotic pathogens; however, the mechanisms employed are unclear. We employed RNAi, qRT-PCR, and Illumina MiSeq 16S rDNA high-throughput sequencing to examine the interaction between two immune genes (Duox in Duox-reactive oxygen species [ROS] immune system and TLR3 in the Toll signaling pathway) and select pathogens common in pig manure to decipher the mechanisms resulting in pathogen suppression. Results indicate Bsf Duox-TLR3 RNAi increased bacterial load but decreased relative abundance of Providencia and Dysgonomonas, which are thought to be commensals in the BSF larval gut. Bsf Duox-TLR3 RNAi also inactivated the NF-κB signaling pathway, downregulated the expression of antimicrobial peptides, and diminished inhibitory effects on zoonotic pathogen. The resulting dysbiosis stimulated an immune response by activating BsfDuox and promoting ROS, which regulated the composition and structure of the gut bacterial community. Thus, BsfDuox and BsfTLR3 are important factors in regulating these key gut microbes, while inhibiting target zoonotic pathogens.


Assuntos
Oxidases Duais/imunologia , Microbioma Gastrointestinal , Proteínas de Insetos/imunologia , Esterco/microbiologia , Simuliidae/imunologia , Receptor 3 Toll-Like/imunologia , Animais , Homeostase , Humanos , Larva/imunologia , Larva/microbiologia , Salmonella/imunologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Transdução de Sinais , Simuliidae/microbiologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/imunologia , Suínos , Zoonoses/imunologia , Zoonoses/microbiologia
7.
Poult Sci ; 99(4): 2125-2135, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241498

RESUMO

Applying broiler litter containing extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) to arable land poses a potential risk for humans to get colonized by contact with contaminated soil or vegetables. Therefore, an inactivation of these bacteria before land application of litter is crucial. We performed 2 short-term litter storage trials (one in summer and winter, respectively), each covering a time span of 5 D to investigate the effectiveness of this method for inactivation of ESBL-producing E. coli in chicken litter. Surface and deep litter samples were taken from a stacked, ESBL-positive chicken litter heap in triplicates in close sampling intervals at the beginning and daily for the last 3 D of the experiments. Samples were analyzed quantitatively and qualitatively for ESBL-producing E. coli, total E. coli, and enterococci. Selected isolates were further characterized by whole-genome sequencing (WGS). In the depth of the heap ESBL-producing E. coli were detected quantitatively until 72 h and qualitatively until the end of the trial in winter. In summer detection was possible quantitatively up to 36 h and qualitatively until 72 h. For surface litter samples a qualitative detection of ESBL-producing E. coli was possible in all samples taken in both trials. In the deep samples a significant decrease in the bacterial counts of over 2 Log10 was observed for total E. coli in the winter and for total E. coli and enterococci in the summer. Genetic differences of the isolates analyzed by WGS did not correlate with survival advantage. In conclusion, short-term storage of chicken litter stacked in heaps is a useful tool for the reduction of bacterial counts including ESBL-producing E. coli. However, incomplete inactivation was observed at the surface of the heap and at low ambient temperatures. Therefore, an extension of the storage period in winter as well as turning of the heap to provide aerobic composting conditions should be considered if working and storage capacities are available on the farms.


Assuntos
Clima , Escherichia coli/fisiologia , Esterco/microbiologia , Viabilidade Microbiana , Tempo (Meteorologia) , Proteínas de Bactérias/metabolismo , Escherichia coli/classificação , Fazendas , Alemanha , Estações do Ano , beta-Lactamases/metabolismo
8.
Ecotoxicol Environ Saf ; 197: 110567, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32289631

RESUMO

The random discharge of livestock waste from family farms without utilization and treatment has caused great pressure on the rural ecological environment and gravely increased the environmental pollution. In this study, we targeted 26 family livestock farms to assess the occurrence characteristics of antibiotic resistance genes (ARGs) in livestock waste and its receiving farmland environment in Erhai Lake basin of China by real-time fluorescence quantitative PCR. The results showed that various common ARGs and some high-risk ARGs (i.e., blaampC, blaOXA-1 and blaTEM-1) were prevalent in family livestock waste, and the pollution of tetracycline resistance genes was the most serious in these family livestock farms. Meanwhile, we also found that the ARG levels were higher in family chicken farms than that in pig and cattle farms, and ARGs pollution in layer waste and sow waste was more severe than that in broiler waste and piglet/fattening pig waste, respectively. Troublesomely, significant ARGs levels could be discharged via manure application, further causing the increase of ARGs abundance in soil environment (approximately 11-36 times). This study demonstrated the high prevalence and severity of ARGs contamination in family livestock farms, also emphasizing that family livestock waste was a non-ignored important pollutant resource of ARGs in the environment.


Assuntos
Resistência Microbiana a Medicamentos/genética , Microbiologia Ambiental , Poluentes Ambientais/análise , Gado/microbiologia , Aves Domésticas/microbiologia , Animais , Antibacterianos/farmacologia , Bovinos , Galinhas , China , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Monitoramento Ambiental , Fazendas , Genes Bacterianos , Esterco/microbiologia , Suínos , Águas Residuárias/microbiologia
9.
Chemosphere ; 253: 126687, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298914

RESUMO

The impact on H2S alleviation and methane yield enhancement after submitting the anaerobic digestion of chicken manure to a finite amount of air was investigated. The largest reduction in the H2S biogas content (58% lower) occurred when air intensity of 30 ml/g VSin was injected into the reactors. Consequently, a maximum methane yield (335 mL-g VSin-1), which was 77% higher than the control, was concurrently achieved. Slight sulfate accumulation (<330 mg L-1) was observed inside the micro-aerated digesters with higher air intensities, suggesting a suppression of sulfide inhibition. Bacterial diversity/richness was enhanced in these digesters while the relative abundance of Methanocelleus increased by 36%. The most important contributing factor to enhancement was the synergistic effect resulting from increments in the hydrolysis rate and the suppression of sulfide inhibition. The results highlighted the potential of in situ H2S mitigation with the added benefit of methane yield enhancement.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sulfeto de Hidrogênio/química , Anaerobiose , Animais , Bactérias , Biocombustíveis , Reatores Biológicos , Galinhas , Hidrólise , Esterco/microbiologia , Metano , Sulfatos
10.
Can J Microbiol ; 66(10): 549-561, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32330390

RESUMO

Agricultural practices such as manure applications could contribute to the spread of antibiotic resistance genes (ARGs) within the environment. Our objective was to assess the impact of certain fertilization methods (mineral or manure) and tillage practices (reduced or conventional) on the presence of ARGs and bacteria in soil and drainage water under wheat and grain corn crops. Targeted ARGs tet(T), sul1, and blaCTX-M-1 in liquid hog manure, soil, and water samples were quantified by qPCR. Conventional PCR was used to detect mcr-1 and mcr-2. ARGs in control plots were detected despite the absence of manure, representing an environmental reservoir of resistant microorganisms. The manure application rate higher than 39 m3/ha increased tet(T) and sul1 gene concentrations in soil for more than 180 days. Tillage practices had no impact on ARG concentrations in soil and water samples. The blaCTX-M-1 gene was only detected in seven water samples in 2016, but no link was established with the treatments. The mcr-1 and mcr-2 genes were not detected in all tested samples. This study demonstrated that tet(T) and sul1 gene concentrations increased in soil after liquid hog manure application as well as in drainage water in the next weeks.


Assuntos
Agricultura/métodos , Farmacorresistência Bacteriana/genética , Esterco/microbiologia , Microbiologia do Solo , Microbiologia da Água , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Genes Bacterianos , Suínos
11.
Artigo em Inglês | MEDLINE | ID: mdl-32192171

RESUMO

(1) Objective: The objective of this study was to screen amoxicillin (AMX)-degrading bacterial strains in pig manure and optimize the fermentation conditions for these strains to achieve high fermentation rate, which can provide an effective way for the practical application of bacterial strains as antibiotic-degrading bacterial in treating livestock waste for antibiotic residues. (2) Methods: Antibiotic susceptibility tests and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) were employed to screen AMX-degrading bacterial strains in pig manure. The culture conditions were optimized for AMX-degrading bacterial strains using Plackeet-Burman design (PBD), the steepest ascent design, and the response surface methods, coupled with the Box-Behnken design (BBD). The effects of culture time, temperature, rotator (mixing) speed, inoculum level, and initial pH value on the growth of AMX-degrading strains were investigated. Experimental data obtained from BBD were utilized to generate a second-order polynomial regression model for evaluating the effects of the tested variables on the optical density at 600 nm (OD600) of culture solutions as the growth indicator for the screened AMX-degrading strains. (3) Results: The initial pH, culture time, and the inoculum level had significant effects on the OD600 value (growth) of the screened AMX-degrading strains. The initial pH value was found to be the most critical factor influencing the growth of bacteria. The optimized culture condition for the bacterial growth determined by the response surface methodology was: the initial pH of 6.9, culture time of 52 h, and inoculum level of 2%. The average OD value of 12 different fermentation conditions in the initial fermentation tests in this study was 1.72 and the optimization resulted in an OD value of 3.00. The verification experiment resulted in an OD value of 2.94, which confirmed the adequacy of the optimization model for the determining the optimal culture condition. (4) Conclusions: The growth of the screened strain of AMX-degrading bacteria could be optimized by changing the fermentation conditions. The optimization could be achieved by using the Box-Behnken response surface method and Plackett-Burman experimental design.


Assuntos
Amoxicilina , Bactérias , Esterco , Amoxicilina/metabolismo , Animais , Bactérias/metabolismo , Meios de Cultura , Fermentação , Esterco/microbiologia , Suínos , Espectrometria de Massas em Tandem
12.
PLoS One ; 15(2): e0214041, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084129

RESUMO

Soil microbial communities and enzyme activities together affect various ecosystem functions of soils. Fertilization, an important agricultural management practice, is known to modify soil microbial characteristics; however, inconsistent results have been reported. The aim of this research was to make a comparative study of the effects of different nitrogen (N) fertilizer rates and types (organic and inorganic) on soil physicochemical properties, enzyme activities and microbial attributes in a greenhouse vegetable production (GVP) system of Tianjin, China. Results showed that manure substitution of chemical fertilizer, especially at a higher substitution rate, improved soil physicochemical properties (higher soil organic C (SOC) and nutrient (available N and P) contents; lower bulk densities), promoted microbial growth (higher total phospholipid fatty acids and microbial biomass C contents) and activity (higher soil hydrolase activities). Manure application induced a higher fungi/bacteria ratio due to a lower response in bacterial than fungal growth. Also, manure application greatly increased bacterial stress indices, as well as microbial communities and functional diversity. The principal component analysis showed that the impact of manure on microbial communities and enzyme activities were more significant than those of chemical fertilizer. Furthermore, redundancy analysis indicated that SOC and total N strongly influenced the microbial composition, while SOC and ammonium-N strongly influenced the microbial activity. In conclusion, manure substitution of inorganic fertilizer, especially at a higher substitution rate, was more efficient for improving soil quality and biological functions.


Assuntos
Fertilizantes/efeitos adversos , Esterco/microbiologia , Microbiota/efeitos dos fármacos , Microbiologia do Solo , Verduras/crescimento & desenvolvimento , Apium/crescimento & desenvolvimento , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Lycopersicon esculentum/crescimento & desenvolvimento , Solo/química
13.
Chemosphere ; 247: 125871, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069711

RESUMO

To investigate how the changes in performance and the microbial community of the co-digestion system of Pennisetum hybrid and pig manure, two co-digestion systems in a semi-continuous mode were established at different grass:manure mixture ratios (50:50 and 75:25), and at variable organic loading rates (OLRs). The two reactors were in a steady-state at the OLRs of 2.0-5.0 g VS/(L·d), with the specific and volumetric biogas yields of 383.86 ± 65.13 to 574.28 ± 72.04 mL/g VS and 0.87 ± 0.07 to 2.36 ± 0.13 m3/(m3·d), respectively. The co-digestion system with a mixture ratio of 75:25 failed at an OLR of 5.5 g VS/(L⋅d). This failure could be attributed to the accumulation of volatile fatty acids (VFAs) owing to the imbalance between acid-production and -oxidation bacteria. By contrast, the co-digestion system with mixture ratio of 50:50 failed at an OLR of 7.0 g VS/(L⋅d), which was likely due to mechanical issues or improper reactor configuration. The genus Proteiniphilum contributed to the increase in total ammonia nitrogen. These findings provide useful guidance for optimizing co-digestion system, enhancing reactor performance and improving the wastes treatment.


Assuntos
Esterco/microbiologia , Pennisetum/metabolismo , Amônia , Anaerobiose , Animais , Bactérias , Biocombustíveis , Reatores Biológicos/microbiologia , Ácidos Graxos Voláteis , Metano , Microbiota , Nitrogênio , Suínos
14.
J Dairy Sci ; 103(3): 2877-2882, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954579

RESUMO

Quantifying antibiotics and antibiotic resistance genes (ARG) in manure exposed to various temperature and pH treatments could guide the development of cost-effective manure handling methods to minimize the spread of antibiotic resistance following land application of manure. This study aimed to investigate the effect of various temperatures and initial pH shocks on the persistence of a cephalosporin antibiotic and ARG in dairy manure slurries. Feces and urine were collected from 5 healthy dairy cows administered with cephapirin (cephalosporin antibiotic) at dry-off via intramammary infusion and were mixed with sterile water to generate manure slurries. In a 28-d incubation study, dairy manure slurries either were continuously exposed to 1 of 3 temperatures (10, 35, and 55°C) or received various initial pH (5, 7, 9, and 12) shocks. Cephapirin was detected in the initial samples and on d 1 following all treatments, but it was undetectable thereafter. This indicates that cephapirin can be rapidly degraded irrespective of temperature and pH treatments. However, degradation was greater on d 1 with the mesophilic (35°C) and thermophilic (55°C) environments compared with the psychrophilic environment (10°C). Increasing pH beyond neutral also accelerated degradation as cephapirin concentrations were lower on d 1 after initial alkaline adjustments (pH 9 and 12) than after neutral and acidic adjustments (pH 7 and 5). No significant effect of temperature or initial pH was observed on abundances of a ß-lactam ARG, cfxA, and a tetracycline ARG, tet(W), implying that bacteria that encoded cfxA or tet(W) genes were not sensitive to temperature or pH in dairy manure slurries. However, abundances of a macrolide ARG, mefA, were decreased in the psychrophilic and thermophilic environments and also following exposure to a strong alkaline shock (pH 12). Our results suggest that increasing temperature or pH during storage of dairy manure slurries could be used together with other on-farm practices that are tailored to reduce the transfer of ARG from manure to the environment following land application.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bovinos/fisiologia , Cefapirina/farmacologia , Resistência Microbiana a Medicamentos , Animais , Cefalosporinas/farmacologia , Fezes/química , Feminino , Concentração de Íons de Hidrogênio , Masculino , Esterco/microbiologia , Temperatura , Urina/química
15.
Int J Food Microbiol ; 319: 108472, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-31901751

RESUMO

The interaction of typical host adapted enteric bacterial pathogens with fresh produce grown in fields is complex. These interactions can be more pronounced in co-managed or sustainable farms where animal operations are, by design, close to fresh produce, and growers frequently move between the two production environments. The primary objectives of this study were to 1) determine the transmission of STEC or enteric pathogens from small and large animal herds or operations to fresh produce on sustainable farms in TN and NC, 2) identify the possible sources that impact transmission of AMR E. coli, specifically STEC on these systems, and 3) WGS to characterize recovered E. coli from these sources. Samples were collected from raw and composted manure, environment, and produce sources. The serotype, virulence, and genotypic resistance profile were determined using the assembled genome sequences sequenced by Illumina technology. Broth microdilution was used to determine the antimicrobial susceptibility of each isolate against a panel of fourteen antimicrobials. The prevalence of E. coli increased during the summer season for all sources tested. ParSNP trees generated demonstrated that the transmission of AMR E. coli is occurring between animal feeding operations and fresh produce. Ten isolates were identified as serotype O45, a serotype that is associated with the "Big Six" group that is frequently linked with foodborne outbreaks caused by non-O157 E. coli. However, these isolates did not possess the stx gene. The highest frequency of resistance was detected against streptomycin (n = 225), ampicillin (n = 190) and sulfisoxazole FIS (n = 140). A total of 35 (13.7%) isolates from two TN farms were positive for the blaCMY (n = 5) and blaTEM (n = 32) genes. The results of this study show the potential of AMR E. coli transmission between animal feeding operations and fresh produce, and more studies are recommended to study this interaction and prevent dissemination in sustainable farming systems.


Assuntos
Escherichia coli Enterotoxigênica/genética , Infecções por Escherichia coli/transmissão , Doenças Transmitidas por Alimentos/microbiologia , Esterco/microbiologia , Verduras/microbiologia , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Escherichia coli Enterotoxigênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Fazendas , Genoma Bacteriano/genética , Testes de Sensibilidade Microbiana , Sorogrupo , Estreptomicina/farmacologia , Sulfisoxazol/farmacologia
16.
Ecotoxicol Environ Saf ; 190: 110149, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31901807

RESUMO

Diets are shown to be capable of shaping the gut microbiota of earthworm, while the effects of distinct foods on bacterial communities of different digestive tracts of earthworm are unknown. For this purpose, cow dung (CD) and domestic sludge (DS) were chosen as diets for earthworms (Eisenia fetida), and different gut contents, namely gizzard + foregut area, hindgut, and mature vermi-compost were sampled for Illumina sequencing analysis. We found that there existed significant reductions in bacterial diversity and abundance in the gizzard + foregut area, where there were stable bacteria with the ability of biodegradation of xenobiotics, such as Amycolatopsis, Methylobacterium, Ralstonia, Ochrobactrum, and Sphingomonas. The decreases could be recovered in the hindgut and mature vermi-compost to different extents, suggesting that a bottleneck effect on the bacterial community occurred in the gizzard + foregut area. Beta-Proteobacteria was the most abundant subclass regardless of the different diets, and bacteria affiliated with gamma-, delta- and epsilon-subclasses were taken as food by the earthworms. Vermi-composts based on the various diets should be used differently according to different aims.


Assuntos
Microbioma Gastrointestinal , Oligoquetos/fisiologia , Eliminação de Resíduos Líquidos , Animais , Bactérias , Biodegradação Ambiental , Bovinos , Compostagem , Análise de Dados , Fezes , Feminino , Trato Gastrointestinal , Esterco/microbiologia , Oligoquetos/efeitos dos fármacos , Oligoquetos/microbiologia , Esgotos , Solo/química , Xenobióticos/metabolismo
17.
Int J Syst Evol Microbiol ; 70(3): 1463-1469, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31961287

RESUMO

Strain MS2379T was isolated from a pasteurized solution sample from a predominantly anaerobic fermentation system processing bovine manure in Pilot Point, Texas. Phylogenetic analyses based on both 16S rRNA gene and rpoB gene sequences showed that MS2379T was most closely related to Paenibacillus polymyxa (DSM 36T), P. jamilae (DSM 13815T), and P. peoriae (DSM 8320T), yet DNA-DNA relatedness through DNA-DNA hybridization revealed only 22.6, 32.0 and 24.7 % relatedness to these three species respectively. Rod-shaped cells of strain MS2379T are Gram-stain variable with sub-terminal, ellipsoidal, deforming endospores. The peptidoglycan contains meso-diaminopimelic acid (mDAP) and the predominant fatty acids are anteiso-C15 : 0 (61.9 %) and anteiso-C17 : 0 (11.6 %), confirming that strain MS2379T has diagnostic features of other Paenibacillus species. The G+C content of MS2379T is 45.9 mol%. Fermentation of glucose yields acid and gas end-products. The polar lipids found were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and glycolipids, but also included some unidentified lipids, aminolipids, aminoglycolipid, and phosphatidylmethylethanolamine. The growth range of MS2379T was observed from 10-45 °C with optimal growth temperature at 30 °C. Growth was observed between pH 6-10 and up to 3 % NaCl. Unlike the most closely related Paenibacillus species, strain MS2379T was negative in the Voges-Proskauer reaction. Nucleic acid, chemotaxonomic and biochemical features support the distinctiveness of strain MS2379T. Thus, strain MS2379T represents a novel species of the genus Paenibacillus for which the name Paenibacillus ottowii sp. nov. is proposed with the type strain MS2379T (=DSM 107750T=ATCC TSD-165T).


Assuntos
Fermentação , Esterco/microbiologia , Paenibacillus/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Bovinos , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Paenibacillus/isolamento & purificação , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Texas
18.
Ecotoxicol Environ Saf ; 191: 110161, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954219

RESUMO

Denitrification and nitrification processes are the two prominent pathways of nitrogen (N) transformation in composting matrix. This study explored the dynamics of denitrifying and nitrifying bacteria at different composting stages of cow manure and corn straw using functional gene sequencing at DNA and cDNA levels. Corresponding agreement among OTUs, NMDS, mental test and network analyses revealed that functional bacteria community compositions and responses to physicochemical factors were different at DNA and cDNA levels. Specifically, some OTUs were detected at the DNA level but were not observed at cDNA level, differences were also found in the distribution patterns of nitrifying and denitrifying bacteria communities at both levels. Furthermore, co-occurrence network analysis indicated that Pseudomonas, Paracoccus and Nitrosomonas were identified as the keystone OTUs at the DNA level, while Paracoccus, Agrobacterium and Nitrosospira were keystone OTUs at the cDNA level. Mantel test revealed that TN, C/N and moisture content significantly influenced both the denitrifying bacteria and ammonia-oxidizing bacteria (AOB) communities at the DNA level. NO3--N, NH4+-N, TN, C/N, and moisture content only registered significant correlation with the nosZ-type denitrifiers and ammonia-oxidizing bacteria (AOB) communities at the cDNA level. Structural equation model (SEM) showed that TN, NH4+-N, and pH were direct and significantly influenced the gene abundance of denitrifying bacteria. Howbeit, TN, NH4+-N, and NO3--N had significant direct effects on amoA gene abundance.


Assuntos
Betaproteobacteria/isolamento & purificação , Compostagem , DNA Bacteriano/genética , DNA Complementar/genética , Esterco/microbiologia , Amônia/metabolismo , Animais , Betaproteobacteria/genética , Betaproteobacteria/metabolismo , Bovinos , China , Desnitrificação , Feminino , Microbiota/genética , Nitrificação , Nitrogênio/metabolismo , Oxirredução
19.
Chemosphere ; 246: 125736, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31896018

RESUMO

Multidrug-resistant Escherichia coli and antibiotic-resistance genes (ARGs) present a danger to public health. However, information on the dissemination potentials of antibiotic resistance among bacteria from different environments is lacking. We isolated multiple antibiotic-resistant Escherichia spp. from animal farms, hospitals, and municipal wastewater-treatment plants (MWWTPs) using culture-based methods, and carried out resistance phenotype and gene analyses. Thirty-five isolates of multiple antibiotic-resistant Escherichia spp. were further screened to detect 61 ARGs, 18 mobile genetic elements (MGEs), and gene cassettes. The isolates from livestock manure and MWWTPs showed greater diversity in plasmid profiling than hospital wastewater. Each Escherichia sp. carried 21-26 ARGs and 8-12 MGEs. In addition, 11 gene cassettes were detected in 34 Escherichia isolates, with greater diversity in livestock manure and MWWTPs than in hospital wastewater. The results indicated that the potential for ARG transfer was higher in livestock manure and MWWTPs compared with human clinical sources, possibly related to the high occurrence of both residual antibiotics and heavy metals in these environments.


Assuntos
Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Genes Bacterianos , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Escherichia , Humanos , Gado , Esterco/microbiologia , Metais Pesados , Plasmídeos , Águas Residuárias/microbiologia
20.
PLoS One ; 15(1): e0227136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923233

RESUMO

Antibiotics are administered to livestock in animal feeding operations (AFOs) for the control, prevention, and treatment of disease. Manure from antibiotic treated livestock contains unmetabolized antibiotics that provide selective pressure on bacteria, facilitating the expression of anti-microbial resistance (AMR). Manure application on row crops is an agronomic practice used by growers to meet crop nutrient needs; however, it can be a source of AMR to the soil and water environment. This study in central Iowa aims to directly compare AMR indicators in outlet runoff from two adjacent (221 to 229 ha) manured and non-manured catchments (manure comparison), and among three catchments (600 to 804 ha) with manure influence, no known manure application (control), and urban influences (mixed land use comparison). Monitored AMR indicators included antibiotic resistance genes (ARGs) ermB, ermF (macrolide), tetA, tetM, tetO, tetW (tetracycline), sul1, sul2 (sulfonamide), aadA2 (aminoglycoside), vgaA, and vgaB (pleuromutilin), and tylosin and tetracycline resistant enterococci bacteria. Results of the manure comparison showed significantly higher (p<0.05) tetracycline and tylosin resistant bacteria from the catchment with manure application in 2017, but no differences in 2018, possibly due to changes in antibiotic use resulting from the Veterinary Feed Directive. Moreover, the ARG analysis indicated a larger diversity of ARGs at the manure amended catchment. The mixed land use comparison showed the manure amended catchment had significantly higher (p<0.05) tetracycline resistant bacteria in 2017 and significantly higher tylosin resistant bacteria in 2017 and 2018 than the urban influenced catchment. The urban influenced catchment had significantly higher ermB concentrations in both sampling years, however the manure applied catchment runoff consisted of higher relative abundance of total ARGs. Additionally, both catchments showed higher AMR indicators compared to the control catchment. This study identifies four ARGs that might be specific to AMR as a result of agricultural sources (tetM, tetW, sul1, sul2) and optimal for use in watershed scale monitoring studies for tracking resistance in the environment.


Assuntos
Agricultura , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Água Subterrânea/microbiologia , Esterco/microbiologia , Animais , Enterococcus/genética , Iowa , Gado/microbiologia , Tetraciclina/farmacologia , Tilosina/farmacologia
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