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1.
Microbiome ; 9(1): 81, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795006

RESUMEN

BACKGROUND: Research is needed to delineate the relative and combined effects of different antibiotic administration and manure management practices in either amplifying or attenuating the potential for antibiotic resistance to spread. Here, we carried out a comprehensive parallel examination of the effects of small-scale (> 55 °C × 3 days) static and turned composting of manures from dairy and beef cattle collected during standard antibiotic administration (cephapirin/pirlimycin or sulfamethazine/chlortetracycline/tylosin, respectively), versus from untreated cattle, on "resistomes" (total antibiotic resistance genes (ARGs) determined via shotgun metagenomic sequencing), bacterial microbiota, and indicator ARGs enumerated via quantitative polymerase chain reaction. To gain insight into the role of the thermophilic phase, compost was also externally heated to > 55 °C × 15 days. RESULTS: Progression of composting with time and succession of the corresponding bacterial microbiota was the overarching driver of the resistome composition (ANOSIM; R = 0.424, p = 0.001, respectively) in all composts at the small-scale. Reduction in relative abundance (16S rRNA gene normalized) of total ARGs in finished compost (day 42) versus day 0 was noted across all conditions (ANOSIM; R = 0.728, p = 0.001), except when externally heated. Sul1, intI1, beta-lactam ARGs, and plasmid-associated genes increased in all finished composts as compared with the initial condition. External heating more effectively reduced certain clinically relevant ARGs (blaOXA, blaCARB), fecal coliforms, and resistome risk scores, which take into account putative pathogen annotations. When manure was collected during antibiotic administration, taxonomic composition of the compost was distinct according to nonmetric multidimensional analysis and tet(W) decayed faster in the dairy manure with antibiotic condition and slower in the beef manure with antibiotic condition. CONCLUSIONS: This comprehensive, integrated study revealed that composting had a dominant effect on corresponding resistome composition, while little difference was noted as a function of collecting manure during antibiotic administration. Reduction in total ARGs, tet(W), and resistome risk suggested that composting reduced some potential for antibiotic resistance to spread, but the increase and persistence of other indicators of antibiotic resistance were concerning. Results indicate that composting guidelines intended for pathogen reduction do not necessarily provide a comprehensive barrier to ARGs or their mobility prior to land application and additional mitigation measures should be considered. Video Abstract.


Asunto(s)
Compostaje , Estiércol , Animales , Antibacterianos/farmacología , Bovinos , Farmacorresistencia Microbiana , Genes Bacterianos/genética , ARN Ribosómico 16S/genética , Suelo
2.
Bioresour Technol ; 331: 125023, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33798857

RESUMEN

Anaerobic co-digestion of organic fraction of municipal solid waste with solid content greater than 20% and chicken manure was investigated using leach-bed reactors in the framework of Middle East and North African countries. The objectives of the experiments were to determine the optimal ratio of organic fraction, chicken manure and solid inoculum, to compare temperature conditions and usage of liquid inoculum or water in percolation process. The highest specific methane yield (SMY) (236 LN ∙ kg-1 VS) was received in the reactors with 20/80 organic fraction/solid inoculum ratio under thermophilic conditions with liquid inoculum percolation. Under the same conditions but mesophilic temperature, SMY dropped by 12%. Replacing liquid inoculum by water led to 172 LN ∙ kg-1 VS. Addition of chicken manure to the substrate mixture positively influences a start-up phase and keeps pH in optimal range 6.5-8, despite the high ammonia concentration.


Asunto(s)
Eliminación de Residuos , Residuos Sólidos , Anaerobiosis , Reactores Biológicos , Digestión , Estiércol , Metano
3.
Environ Sci Technol ; 55(9): 5815-5825, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33856195

RESUMEN

Nano and colloidal particles (1-1000 nm) play important roles in phosphorus (P) migration and loss from agricultural soils; however, little is known about their relative distribution in arable crop soils under varying agricultural geolandscapes at the regional scale. Surface soils (0-20 cm depth) were collected from 15 agricultural fields, including two sites with different carbon input strategies, in Zhejiang Province, China, and water-dispersible nanocolloids (0.6-25 nm), fine colloids (25-160 nm), and medium colloids (160-500 nm) were separated and analyzed using the asymmetrical flow field flow fractionation technique. Three levels of fine-colloidal P content (3583-6142, 859-2612, and 514-653 µg kg-1) were identified at the regional scale. The nanocolloidal fraction correlated with organic carbon (Corg) and calcium (Ca), and the fine colloidal fraction with Corg, silicon (Si), aluminum (Al), and iron (Fe). Significant linear relationships existed between colloidal P and Corg, Si, Al, Fe, and Ca and for nanocolloidal P with Ca. The organic carbon controlled colloidal P saturation, which in turn affected the P carrier ability of colloids. Field-scale organic carbon inputs did not change the overall morphological trends in size fractions of water-dispersible colloids. However, they significantly affected the peak concentration in each of the nano-, fine-, and medium-colloidal P fractions. Application of chemical fertilizer with carbon-based solid manure and/or modified biochar reduced the soil nano-, fine-, and medium-colloidal P content by 30-40%; however,the application of chemical fertilizer with biogas slurry boosted colloidal P formation. This study provides a deep and novel understanding of the forms and composition of colloidal P in agricultural soils and highlights their spatial regulation by soil characteristics and carbon inputs.


Asunto(s)
Fósforo , Suelo , Carbono , China , Coloides , Estiércol , Fósforo/análisis
4.
Artículo en Inglés | MEDLINE | ID: mdl-33803027

RESUMEN

Manure and digestate liquid fractions are nutrient-rich effluents that can be fractionated and concentrated using membranes. However, these membranes tend to foul due to organic matter, solids, colloids, and inorganic compounds including calcium, ammonium, sodium, sulfur, potassium, phosphorus, and magnesium contained in the feed. This review paper is intended as a theoretical and practical tool for the decision-making process during design of membrane-based systems aiming at processing manure liquid fractions. Firstly, this review paper gives an overview of the main physico-chemical characteristics of manure and digestates. Furthermore, solid-liquid separation technologies are described and the complexity of the physico-chemical variables affecting the separation process is discussed. The main factors influencing membrane fouling mechanisms, morphology and characteristics are described, as well as techniques covering membrane inspection and foulant analysis. Secondly, the effects of the feed characteristics, membrane operating conditions (pressure, cross-flow velocity, temperature), pH, flocculation-coagulation and membrane cleaning on fouling and membrane performance are presented. Finally, a summary of techniques for specific recovery of ammonia-nitrogen, phosphorus and removal of heavy metals for farm effluents is also presented.


Asunto(s)
Estiércol , Nitrógeno , Amoníaco , Anaerobiosis , Nitrógeno/análisis , Fósforo
5.
An Acad Bras Cienc ; 93(1): e20181384, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33886698

RESUMEN

Organic manures are more preferred and environmentally friendly than chemical fertilizers for minimally contaminating soil, water and environmental resources, but the determination of right source of organic manures continues to remain an unexplored aspect. Considering the important issue, a multi-year field trial was carried out to determine the response of forage soybean to four sources of nutrients such as chemical fertilizers (IF), poultry litter (PL), bovine's farm yard slurry (BFYS) and sewage sludge (SS) and their seven binary combinations (PL+BFYS, PL+SS, PL+IF, BFYS+SS, BFYS+IF, SS+IF and PL+BFYS+SS). Supplementation of organic manures with mineral fertilizers remained superior to their sole application, particularly BFYS + IF was found significantly (p≤0.05) superior for yielding the highest fresh biomass (23.9, 26.4 and 25.7 t ha-1) with improved nutritional quality. The same combination of integrated fertilizer management also recorded higher sustainability as per sustainable forage yield index along with the highest net income and the benefit-cost ratio. PL and SS applied in conjunction with IF performed better than sole or binary application of organic manures. Therefore, BFYS + IF may be recommended for adoption to produce comparable forage yield and nutritional quality of soybean along with reducing dependency on chemical fertilizers.


Asunto(s)
Estiércol , Soja , Agricultura , Animales , Bovinos , Fertilizantes , Valor Nutritivo , Suelo
6.
Bioresour Technol ; 332: 125079, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33813177

RESUMEN

Short-term composting of raw materials for preparing oyster mushroom cultivation media is widely used in China, and its microbial mechanism needs to be further studied. 11-days' peach sawdust-based composting was performed to evaluate material conversion and microbial succession using physicochemical analysis and 16S rRNA and ITS sequencing. Composting bacteria demonstrated much higher abundance than fungi. Firmicutes, Actinobacteriota, and Proteobacteria were the dominant bacterial phyla, while most of fungal species belonged to Ascomycota. Moisture was the key factor at the beginning, while total nitrogen, temperature, and lignin became main influencing factors for composting maturity. Actinobacteriota, Firmicutes, and Proteobacteria of bacterial phyla, Eurotiomycetes and Sordariomycetes of fungal classes involved in lignocellulosic degradation. Bacterial function prediction analysis showed that carbohydrate metabolism and amino acid metabolism were the main metabolic pathways. These results confer a better understanding of material and microbial succession during short-term composting and also provide valuable utilization in mushroom industry.


Asunto(s)
Compostaje , Microbiota , Prunus persica , China , Estiércol , ARN Ribosómico 16S/genética , Suelo
7.
Bioresour Technol ; 332: 125076, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33819854

RESUMEN

The mcr-1 and blaNDM-1 elimination in copper contamination poultry manure was evaluated by semi-permeable membrane composting. The results showed the mcr-1 in control and high copper groups could not be removed, but mcr-1 decreased superlatively 80.1% in low copper treatment group. BlaNDM-1 was increased after composting, especially the copper addition groups, the results indicated that the relative abundance of mcr-1 and blaNDM-1 was obviously different in the different pile layers of copper treatment groups. Three mobile gene elements (MEGs) correlated both mcr-1 and blaNDM-1,copB correlated mcr-1, czcA and copA correlated both mcr-1 and blaNDM-1. The major phyla were Firmicutes, Bacteroidota, Actinobacteriota and Proteobacteria in all layers. The correlation analysis showed that the antibiotic resistance genes (ARGs) potential hosts could be influenced by copper form and physicochemical parameters. Semi-permeable membrane composting could decrease the abundance of major potential pathogens. Furthermore, the composting pile was not homogeneous by semi-permeable membrane composting.


Asunto(s)
Compostaje , Animales , Antibacterianos , Cobre , Genes Bacterianos , Estiércol , Aves de Corral , beta-Lactamasas
8.
Bioresour Technol ; 332: 125084, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33819855

RESUMEN

A weakly acidic ammonium-rich wastewater (STL) was intended to reuse as a moisture conditioning agent for composting to increase nitrogen content of compost. The influence of adding STL in the mesophilic period (MP), thermophilic period (TP), and cooling period (CP) on composting performance was investigated. Results revealed that organic degradation was strongly suppressed in MP, whereas no difference (p > 0.05) was observed between CP and control group (using tap water as moisture conditioning agent). The hydrolysis and mineralization of organic matter in TP were partly stimulated because reusing STL reduced free ammonia concentrations (<400 mg/L) of windrows. Additionally, the ammonium and nitrate nitrogen content of compost in TP increased by 71% and 425% without additional greenhouse gas emissions compared with control group. Therefore, ammonium-rich wastewater like STL could substitute tap water to condition compost moisture content and increase the nitrogen content of compost during the thermophilic composting period.


Asunto(s)
Compuestos de Amonio , Compostaje , Estiércol , Nitrógeno/análisis , Suelo , Aguas Residuales
9.
Bioresour Technol ; 332: 125033, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33826979

RESUMEN

Food and energy requirements are increasing globally, and the challenge is to meet these demands in a sustainable manner. Oil palm has a relatively high productivity, but produces the lignocellulosic residue of empty fruit bunches (OPEFB). In this study, wet oxidation pretreatment is utilized to overcome the recalcitrance of OPEFB during semi-continuous anaerobic digestion (AD) with between 19.7 and 52.7% improvement over the control, and near total cellulose and hemicellulose content could be degraded. Clarified manure, the water phase of cattle and dairy manure after filtration, is further tested for its effect on methane production by providing necessary micronutrients and vitamins. An increase of 49% was found after addition of clarified manure to OPEFB compared to without this addition.


Asunto(s)
Frutas , Estiércol , Anaerobiosis , Animales , Biocombustibles , Bovinos , Celulosa , Peróxido de Hidrógeno , Metano , Aceite de Palma
10.
Bioresour Technol ; 332: 125087, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33831791

RESUMEN

The effects of functional membrane covering (FMC) on nitrogen transformation and related functional genes during aerobic composting were investigated by performing a comparable experiment. The FMC increased the pile temperature, promoted compost maturity, and decreased nitrogen loss. The FMC reduced NH3 and N2O emissions by 7.34% and 26.27%, respectively. The water film and the micro-positive pressure environment under the membrane effectively prevented NH3 escaping. The FMC up-regulated the amoA gene copy number (promoting NH3/NH4+ oxidation). The reduction of N2O emission by the FMC was mainly related to denitrifying genes (nirK, nirS, and nosZ). The FMC down-regulated the nirK and nirS gene copy numbers, but up-regulated the nosZ gene copy number. Pearson correlation analysis indicated that the functional membrane characteristics and differences between the composting pile environments caused by the FMC significantly affected the nitrogen forms and the related functional genes. The FMC strongly decreased nitrogen emissions and therefore conserved nitrogen.


Asunto(s)
Compostaje , Desnitrificación , Estiércol , Nitrógeno , Óxido Nitroso/análisis , Suelo
11.
Bioresour Technol ; 332: 125129, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33857866

RESUMEN

This study investigated effects of high-nitrogen source (urea) (R_UR) and protein-like nitrogen source (chicken manure) (R_CM) on humification process during lignocellulose biomass composting. It demonstrated that decreasing ratio of crude fiber (CF), polysaccharide (PS) and amino acids (AAs) in R_CM (29.75%, 53.93% and 73.73%, respectively) was higher than that in R_UR (14.73%, 28.74% and 51.92%, respectively). Humic substance (HS) concentration increased by 7.51% and 73.05% during R_UR and R_CM composting, respectively. The lower total links, more independent modularization and higher proportion of positive correlations between functional bacteria and organic components was observed with R_CM network than R_UR, indicating that protein-like nitrogen source supply may alleviate competition within bacterial community. Moreover, chicken manure supply favorably selects greater special functional bacterial taxa (Pusillimonas, Pedomicrobium, Romboustia and other 24 genus) related to AAs and stimulates the collaborative division of bacterial community. This is significance for strengthening effective transformation of organic components.


Asunto(s)
Compostaje , Oryza , Animales , Bacterias , Estiércol , Nitrógeno , Suelo
12.
Bioresour Technol ; 332: 125133, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33857867

RESUMEN

The objectives of this study were to investigate the degradation characteristics of different microplastics (polyethylene (PE), polyvinyl chloride (PVC), polyhydroxyalkanoates (PHA)) and their effect on the bacterial community during composting. In this study, 0.5% PE, 0.5% PVC and 0.5% PHA microplastics were individually added to the mixture of cow manure and sawdust and then composted for 60 days. The treatment without microplastics was regarded as control. Results indicated that the abundance and smaller size (0-800 µm) of microplastics in all treatments obviously decreased after composting, except PVC treatment. The surface morphology of all microplastics occurred obvious erosions and cracks and the carbon content of PE, PVC and PHA microplastics were reduced by 30, 17 and 30%, respectively. After composting, all microplastics were significantly oxidized and the functional groups O-H, C=O and C-O increased. Furthermore, all microplastics exposure reduced the richness and diversity of bacteria community at thermophilic phase, especially PVC microplastics.


Asunto(s)
Compostaje , Microbiota , Estiércol , Microplásticos , Plásticos
13.
Bioresour Technol ; 332: 125080, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33865011

RESUMEN

Performance and environ-economic impacts were compared for anaerobic digestion (AD) of dairy manure and cucumber residues from liquid to solid state. Environ-economic evaluation of the overall AD process at different total solids (TS) was performed with the estimated treatment capacity of 9600 tons/year and service life of 20 years. Results showed that TS increase from 6% to 22% enhanced both cumulative and volumetric methane (CH4) production. Further TS increase to 25%, however, reduced CH4 yield. Environ-economic assessment indicated that TS increase enhanced volumetric waste treatment capacity and thus AD environmental footprints. Environmental credits from digestate and biogas utilization could compensate the adverse environmental impacts of other processes in AD plants. Furthermore, biogas and nutrients in digestate determined AD net-present value. As a result, solid state AD was more profitable with higher CH4 yield and more nutrients in both biosolids and digested effluent of digestate than its liquid and hemi-solid counterparts.


Asunto(s)
Biocombustibles , Estiércol , Agricultura , Anaerobiosis , Reactores Biológicos , Metano
14.
J Environ Manage ; 289: 112576, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33865023

RESUMEN

The increasing prevalence of antibiotic resistance genes (ARGs) in the soil environment poses a serious threat to crop safety and even public health. In this study, the fate of ARGs in the soil was investigated during the growth period of pakchoi and after harvesting with the application of different kinds of fertilizers. The result showed that increasing rate of soil ARGs during the growth period of pakchoi followed the order of composted manure > commercial fertilizer > mineral fertilizer. After harvesting, soil ARGs abundance treated with mineral fertilizer, commercial fertilizer or composted manure significantly increased by 0.63, 3.19 and 8.65 times (p < 0.05), respectively, compared with the non-fertilized soil. The ARGs abundance in the pakchoi treated with composted manure was significantly higher than that of treatments with mineral fertilizer and commercial organic fertilizer. These findings indicated the application of composted pig manure would significantly increase the pollution load of ARGs in farmland soil and plant, and also promote the proliferation of farmland ARGs. Principal component analysis suggested that bacterial communities might have a significant influence on ARGs changes during the growth period of pakchoi. Network analysis further indicated ARGs changes may be mainly related to their host bacteria (including Gammaproteobacteria, Flavobacteriia and Bacilli). The results provided a proper method and useful information on reducing transmission risk of ARGs and control the propagation of ARGs in agricultural activities.


Asunto(s)
Fertilizantes , Suelo , Animales , Antibacterianos/farmacología , Farmacorresistencia Microbiana/genética , Granjas , Fertilizantes/análisis , Genes Bacterianos/genética , Estiércol , Microbiología del Suelo , Porcinos
15.
Ying Yong Sheng Tai Xue Bao ; 32(2): 564-570, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33650366

RESUMEN

To explore the mechanism of exogenous organic materials enhancing soil organic carbon and soil fertility, based on a long-term experiment located in Hengyang Red Soil Experimental Station, we examined the effects of winter green manure and straw returning patterns (CK, winter fallow; MV, winter Chinese milk vetch; S, early-season rice straw total returning; DS, early-season and late-season rice straw total returning; SMV, winter Chinese milk vetch + early-season rice straw total returning; DSMV, winter Chinese milk vetch + early-season and late-season rice straw total returning) on soil aggregates and organic functional groups. The results showed that the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) in double cropping rice soil was the highest with a ratio of about 72.1%-81.8%, and the organic carbon content in the two kinds of aggregates was as high as 12.1-20.7 g·kg-1, accounting for 22.7%-59.0% of the total organic carbon. The main organic functional group in paddy soil was polysaccharides, followed by aliphatic carbon and aromatic carbon. The abundance of all those groups was affected by winter Chinese milk vetch growing and straw returning. Compared with other treatments, DSMV significantly increased the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) and favored the accumulation of inert carbon such as aromatic carbon in the two kinds of aggregates. DSMV could enhance the stability of soil aggregates and organic matter, which had high potential in the real agricultural production.


Asunto(s)
Oryza , Suelo , Agricultura , Carbono , Estiércol , Estaciones del Año
16.
Sci Total Environ ; 771: 145454, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33736144

RESUMEN

Biochars have been used to reduce gas emissions from manure composting practices and to recover nutrients from wastewater because of their effective sorption capacity. However, relatively less is known about the impacts of different alkaline biochars on the gas emissions from liquid manure. Materials including two commercial biochars prepared from walnut shell (WA) and coconut shell (CC), respectively, and coal (CO) were applied (with manure/biochar ratio of 20:1 in weight) to examine their influence on NH3, CH4, and N2O emissions from liquid pig manure during a 68-d period in comparison with a control (CK, without biochars), and to investigate the evolution of the manure N mass balances and the changes in biochar properties during liquid manure storage to understand the characteristics of biochar. Compared with the CK, the application of WA, CC, and CO biochars increased the NH3 emissions by 4.00, 3.87, and 1.23 times, respectively, the absorbed N content of the biochars was markedly lower than the enhanced gaseous losses through NH3 emissions. Similarly, the total greenhouse gas (GHG) emissions from the manure with WA, CC, and CO biochar application were 6.28, 5.55, and 0.83 times greater than those observed with the CK, respectively, and were mainly attributed to the enhanced CH4 emissions. The significant contribution (5%-12%) of indirect GHG emissions from the enhanced NH3-N losses was also identified. The hypothesis for the enhanced gas emissions from liquid manure with biochar addition has been discussed in the present study; however, further investigation in the future is warranted.


Asunto(s)
Estiércol , Metano , Amoníaco/análisis , Animales , Carbón Orgánico , Óxido Nitroso/análisis , Suelo , Porcinos
17.
Bioresour Technol ; 331: 125013, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33773414

RESUMEN

With the aims of exploring the effectiveness of Cu(II) adsorption performed by cow manure biochars (CMBCs) for the treatment and recycling of livestock wastes, the physicochemical characteristics and Cu(II) adsorption behaviors of CMBCs at various pyrolysis temperatures (T) were analyzed. CMBCs displayed surface heterogeneity and the dominant Cu(II) adsorption reactions were chemical adsorption, including mineral co-precipitation and cations exchange, was account for 93.75% - 97.01% of the adsorption contribution. Pearson correlation analysis and quantitative analysis showed that the adsorption capacity of co-precipitation (Qcp) and cations exchange (Qci) were significantly positively correlated with ash content and cations exchange capacity (p < 0.01), respectively. The quantitative relationships between total adsorption capacity (Qt), Qcp or Qci and T are Qt = 54.01 + 0.39exp(0.0051 T), Qcp = 71.80-101.91exp(-0.0024 T), Qci = 12.25 + 311.73exp(-0.0093 T) and Qt = 0.93 Qci + 0.91 Qcp + 7.70.


Asunto(s)
Estiércol , Pirólisis , Adsorción , Animales , Bovinos , Carbón Orgánico , Femenino , Temperatura
18.
FEMS Microbiol Ecol ; 97(5)2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33784380

RESUMEN

Larvae of the black soldier fly (BSF) can be used to convert organic waste into insect biomass for animal feed. In this process, they interact with microorganisms originating from the substrate, the insect and the environment. The substrate is the main determinant of the larval gut microbiota composition, but inoculation of the substrate with egg-associated bacteria can improve larval performance. We aimed to quantify the relative importance of substrate-associated and egg-associated microorganisms in BSF larval performance, bacterial abundance and bacterial community composition, when larvae were fed with chicken feed or chicken manure. For this, we inactivated substrate-associated microorganisms by autoclaving, or disinfected BSF eggs. Larval survival, weight and proportion of prepupae were determined on day 15. We collected substrate and larval samples on days 0 and 15 and performed 16S rRNA gene-targeted qPCR and amplicon sequencing. In both chicken feed and chicken manure, egg disinfection did not cause any difference in larval performance or overall microbiota composition. In contrast, in chicken manure, substrate-associated microorganisms increased larval biomass and sterilizing the substrate caused major shifts in microbiota. Thus, substrate-associated microorganisms impact not only larval microbiota but also larval performance, whereas egg-associated microorganisms have a minor role in the densities present.


Asunto(s)
Dípteros , Microbiota , Alimentación Animal/análisis , Animales , Larva , Estiércol , ARN Ribosómico 16S/genética
19.
Microbiome ; 9(1): 65, 2021 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-33743832

RESUMEN

BACKGROUND: Viruses are the most abundant biological entities on Earth, known to be crucial components of microbial ecosystems. However, there is little information on the viral community within agricultural waste. There are currently ~ 2.7 million dairy cattle in the UK producing 7-8% of their own bodyweight in manure daily, and 28 million tonnes annually. To avoid pollution of UK freshwaters, manure must be stored and spread in accordance with guidelines set by DEFRA. Manures are used as fertiliser, and widely spread over crop fields, yet little is known about their microbial composition. We analysed the virome of agricultural slurry over a 5-month period using short and long-read sequencing. RESULTS: Hybrid sequencing uncovered more high-quality viral genomes than long or short-reads alone; yielding 7682 vOTUs, 174 of which were complete viral genomes. The slurry virome was highly diverse and dominated by lytic bacteriophage, the majority of which represent novel genera (~ 98%). Despite constant influx and efflux of slurry, the composition and diversity of the slurry virome was extremely stable over time, with 55% of vOTUs detected in all samples over a 5-month period. Functional annotation revealed a diverse and abundant range of auxiliary metabolic genes and novel features present in the community, including the agriculturally relevant virulence factor VapE, which was widely distributed across different phage genera that were predicted to infect several hosts. Furthermore, we identified an abundance of phage-encoded diversity-generating retroelements, which were previously thought to be rare on lytic viral genomes. Additionally, we identified a group of crAssphages, including lineages that were previously thought only to be found in the human gut. CONCLUSIONS: The cattle slurry virome is complex, diverse and dominated by novel genera, many of which are not recovered using long or short-reads alone. Phages were found to encode a wide range of AMGs that are not constrained to particular groups or predicted hosts, including virulence determinants and putative ARGs. The application of agricultural slurry to land may therefore be a driver of bacterial virulence and antimicrobial resistance in the environment. Video abstract.


Asunto(s)
Bacteriófagos , Animales , Bacteriófagos/genética , Bovinos , Ecosistema , Estiércol , Virulencia
20.
Bull Environ Contam Toxicol ; 106(5): 892-898, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33709159

RESUMEN

Clothianidin is drenched at planting to manage the termites of sugarcane. The application of organic manures at planting is also in vogue to conserve the soil moisture in the tropical ecosystem. Hence, the persistence behaviour of clothianidin was studied in the sandy clay loam soil of tropical sugarcane ecosystem under different organic manuring. The clothianidin residues persisted up to 90th DAT and reached below the limit of quantification (LOQ = 0.005 µg/g) on 105th DAT both in the manurial and non-manurial soils. The half-lives of clothianidin were in the range of 22.4-24.8 days in the manurial soils as against 21 days in the non-manurial soil, indicating the insignificant positive impact of organic manures on the soil persistence of clothianidin. The clothianidin residues in the soil were predicted to pose unacceptable to medium level of risk to earthworms during the course of its dissipation in the tropical sugarcane environment.


Asunto(s)
Saccharum , Contaminantes del Suelo , Ecosistema , Guanidinas , Estiércol , Neonicotinoides , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis , Tiazoles
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