Swine Manure Compost Research Articles

SiO2 nanoparticles can enhance nitrogen retention and reduce copper resistance genes during aerobic composting of swine manure

SiO2 nanoparticles (SiO2 NPs) are low-cost, environmentally friendly materials with significant potential to remove pollutants from complex environments. In this study, SiO2 NPs were used for the first time as an additive in aerobic composting to enhance nitrogen retention and reduce the expression of copper resistance genes. The addition of 0.5 g kg−1 SiO2 NPs effectively reduced nitrogen loss by 72.33 % by decreasing denitrification genes (nosZ, nirK, and napA) and increasing nitrogen fixation gene (nifH). The dominant factors affecting nitrification and denitrification genes were Firmicutes and C/N ratio. Additionally, SiO2 NPs decreased copper resistance genes by 28.96 % − 37.52 % in compost products. Copper resistance genes decreased most in the treatment with 0.5 g kg−1 SiO2 NPs. In summary, 0.5 g kg−1 SiO2 NPs have the potential to reduce copper resistance genes and enhance nitrogen retention during aerobic composting, which may be used to improve compost quality.

Variations in fluorescence properties of humic acids from calcareous soils amended with different swine manures in a long-term soil experiment.

Molecular properties of soil humic acid (HA) can play an important role in the mechanisms regulating plant nutrient availability. This study explores how the structure of HA is altered by long-term treatment with different forms of swine manure and how these changes may influence nutrient availability. Liquid swine manure (LSM), solid swine manure (SSM), and swine manure compost (SMC) were applied to a calcareous soil over 17 years in a long-term soil fertility study. HA was extracted from site soil samples and analyzed using fluorescence spectroscopic techniques, including a Cu2+ quenching experiment, in order to assess differences in the structure and functionality of the soil organic matter (SOM) resulting from these different treatments. Emission spectra of the SSM-HA and SMC-HA are similar, while the LSM-HA is distinct. Procedures such as parallel factor analysis (PARAFAC) decomposition of emission-excitation matrices showed that structures in the SSM-HA and SMC-HA samples have lower complexity, whereas the structures of LSM-HA are of higher complexity. Interactions with Cu2+ at different pH levels indicate that the LSM-HA shows more dynamic conformational changes as well as stronger interactions and higher quenching efficiency compared to the other treatments. Conversely, SMC-HA demonstrates relatively stable binding constant (Ka) values across different pH levels. The binding constants and quenching efficiency of SSM-HA are significantly affected by changes in pH. This study shows distinct structural characteristics of HA formed under different manure management systems and provides valuable insights into how these variations may impact nutrient dynamics in soils.

The enrichment of antibiotic resistance genes in swine manure compost was related to the bulking agent types

Composting is a major method to produce organic fertilizers, and the variation in antibiotic resistance genes (ARGs) during composting is crucial for the safe utilization of mature compost. The effects of different bulking agents (cellulose-rich cornstalk and lignin-rich garden waste) on ARGs variations during swine manure composting were investigated. The results showed that composting thermophilic could effectively reduce ARGs (58–61 %), whereas ARGs rebounded and were enriched with decreasing temperature during the maturation stage. Compared to their initial abundance, ARGs were enriched 6.97 times (cornstalk) and 22.27 times (garden waste) during the maturation period. The ARGs enrichment mechanism in swine manure composting differed for cornstalk and garden waste amendments. The cornstalk was used as the bulking agent, the selective pressure of continuous high temperature resulted in the proliferation of spore-forming bacteria (Bacillus, Sporosarcina and Psychrobacillus), which are potential host bacteria of ARGs and cause ARGs enrichment through vertical gene proliferation. In the garden waste treatment, the enriched ARGs in the final compost were related to horizontal gene transfer mediated by mobile genetic elements (intl1), with the primary potential host bacteria being Bacillus, Saccharomonospora, and Caldicoprobacter. The types of enriched ARGs were consistent across different bulking agents composting process, and the risk genes enriched in the final mature compost included ermB, ermF, sul1, sul2, tetO, and tetX.

A statistical model predicts N mineralization of various organic amendments for paddy fields

ABSTRACT To predict the mineralization of nitrogen(N) in organic amendments in paddy fields, we applied data obtained from incubation experiments under waterlogged conditions by a hierarchical Bayesian model using acid-detergent-soluble organic N (ADSON) as a model input. Each of 20 organic amendments (6 cattle manure composts, 3 swine manure composts, 3 poultry manure composts, 2 oil cakes, 2 rice brans, 1 fish meal, 1 sludge fertilizer, and 2 mixed commercial organic fertilizers) was mixed with paddy soil, and the N mineralization curves obtained after 1, 2, 4, 8, and 12 weeks of waterlogging were incorporated into the model to obtain values of the model parameters k i , α1, and Q 10. All model parameters converged with a mean absolute error (MAE) of 0.044 g N kg−1, a root mean square error (RMSE) of 0.060 g N kg−1, and a model efficiency (EF) of 0.96. These values were comparable to or slightly better than those of a previous model for upland soil conditions. Most of the observed values were within the 95% Bayesian prediction interval, indicating that the model performed well with the observed data. Although it is generally believed that livestock manure composts decompose more slowly than organic fertilizers such as oil cake, the livestock manure composts had a large value of the rate constant k i , presumably because of the initial rapid decomposition of the small amounts of organic N present in them. In paddy fields, the soil conditions are aerobic between the application of organic amendments and water entry. In such a case, we propose the use of the upland field model to predict the mineralization of organic N during the period of aerobic soil conditions and of this study’s model during the period of waterlogging, subtracting the amount of already mineralized N from the parameters N in and ADSON. The model devised here is expected to be useful for fertilization design in organic agriculture and in the reduction of the use of inorganic fertilizer.

Wheat straw biochar as an additive in swine manure Composting: An in-depth analysis of mixed material particle characteristics and interface interactions

In recent research, biochar has been proven to reduce the greenhouse gases and promote organic matter during the composting. However, gas degradation may be related to the microstructure of compost. To investigate the mechanism of biochar additive, composting was performed using swine manure, wheat straw and biochar and representative solid compost samples were analyzed to characterize the mixed biochar and compost particles. We focused on the microscale, such as the particle size distributions, surface morphologies, aerobic layer thicknesses and the functional groups. The biochar and compost particle agglomerations gradually became weaker and the predominant particle size in the experiment group was < 200 μm. The aerobic layer thickness (Lp) was determined by infrared spectroscopy using the wavenumbers 2856 and 1568 cm−1, which was 0–50 μm increased as composting proceeded in both groups. The biochar increased Lp and facilitated oxygen penetrating the compost particle cores. Besides, in the biochar-swine manure particle interface, the aliphatic compound in the organic components degraded and the content of aromaticity increased with the composting process, which was indicated by the absorption intensity at 2856 cm−1 decreasing trend and the absorption intensity at 1568 cm−1 increasing trend. In summary, biochar performed well in the microscale of compost pile.

Assessment of phosphorus status in a calcareous soil receiving long-term application of chemical fertilizer and different forms of swine manures.

The continuous use of organic inputs in crop production calls for an improved understanding of how these inputs might alter soil phosphorus (P). This study assessed how the continuous application of different forms of swine manure influences the mechanism of P transformation and release potential. Soil samples were collected from a clay loam soil receiving no P or 100kg P ha-1 applied as either chemical fertilizer (CHEM), swine liquid manure (SWL), composted swine manure (SWC), or solid swine manure (SWS) every other year for 16 years in a corn-soybean rotation. Available P increased in soils treated with the chemical and organic fertilizers. The greatest increase was found in the SWC and SWS and was closely related to a 1% increase in the organic C content, and 1.3- and 1.2-unit increase in the soil pH for SWC and SWS treatment, respectively. Nonlabile HCl-P form was also higher in SWC- and SWS-treated soils. Despite the similarities between SWS and SWC, SWS significantly had a lower maximum P sorption (Qmax ) and higher equilibrium P concentration at zero net sorption (EPCO) probably related to the higher organic NaOH-P. Similarly, higher organic NaOH-P together with lower cation exchange capacity, aluminum, and calcium explained the lower Qmax in SWL. This suggests that increase in organic NaOH-P forms limits the soil potential to retain P. Overall, the SWL treatment presents a unique effect on changes in soil property and P chemistry that warrants further investigation.

돈분 퇴비화 중 공기 공급량에 따른 질소거동 특성

돈분 퇴비화 중 공기 공급량에 따른 질소거동 특성

Analysis of Molecular Structure Changes in Humic Acids from Manure-Amended Soils over 17 Years Using Elemental Analysis and Solid-State 13C Nuclear Magnetic Resonance Spectroscopy

Soil organic matter (SOM) plays an important role in regulating plant nutrient availability. Here, the effects of the long-term application of different forms of processed swine manure on the SOM structure are explored through the analysis of humic acid (HA) using elemental analysis and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. The HAs from soils amended with liquid swine manure (LSM) and swine manure compost (SMC) are found to be more humified compared to the soils treated with solid swine manure (SSM) and the control (CK). The H/C and O/C molar ratios suggest that carboxyl-rich aliphatic structures are the most important class of biomolecules contributing to the LSM- and SMC-HA structures, while lignin-like structures are the most important biomolecules contributing to the CK- and SSM-HAs. SSM promoted the formation of aliphatic polar structures, which are more susceptible to aerobic biodegradation, whereas the CK facilitated the inclusion of condensed aromatic structures into the HA. Apart from the LSM-HA, the proportion of carboxylic acid functional groups reduced with manure application, while the proportion of phenolic acid functional groups increased. LSM-HA has the highest potential to enhance plant nutrient availability.

Swine-manure composts induce the enrichment of antibiotic-resistant bacteria but not antibiotic resistance genes in soils

Composting is a common and effective strategy for reducing antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) from animal manure. However, it is unclear whether the advantages of composting for the control of ARGs and ARB can be further increased in land application. This study investigated the fate of ARB and ARGs after land application of swine-manure composts (SMCs) to three different soil types (red soil, loess and black soil). The results showed that although the SMCs caused an increase in the abundance of total ARGs in the soil in the short period, they significantly reduced (p < 0.01) the abundance of total ARGs after 82 days compared to the control. The decay rate of ARGs reflected by the half-life times (t1/2) varied by soil type, with red soil being the longest. The SMCs mainly introduced ermF, tetG and tetX into the soils, while these ARGs quickly declined to the control level. Notably, SMCs increased the number of ARB in the soils, especially for cefotaxime-resistant bacteria. Although SMCs only affected the microbiome significantly during the early stage (p < 0.05), it took a much longer time for the microbiome to recover compared to the control. Statistical analysis indicated that changes in the microbial community contributed more to the fate of ARGs during SMCs land application than other factors. Overall, it is proposed that the advantages of ARGs control in the composting process for swine manure can be further increased in land application, but it can still bring some risks in regard to ARB.

Degradation characteristics of intracellular and extracellular ARGs during aerobic composting of swine manure under enrofloxacin stress

Composting has been widely recognized as an effective method for removing antibiotic resistance genes (ARGs) from livestock manure. This study investigated the variation in intracellular ARGs (iARGs) and extracellular ARGs (eARGs) during swine manure composting under low (31.44 ± 1.11 mg/kg DM) and high (176.76 ± 1.90 mg/kg DM) enrofloxacin concentration stress. After 25 days of composting, the rates of total iARG and eARG degradation reached 67.30% ∼ 96.13% and 54.70% ∼ 80.30%, respectively. The fluoroquinolone and multidrug ARGs that were degraded included intracellular and extracellular aac(6′)-ib-cr, qnrS, qnrD, parC, oqxB, acrA, acrB and tolC, but i-parE and e-parE were not eliminated. The main reason for degradation were the alteration of bacterial communities and mobile genetic elements (MGEs). The total absolute abundances of iARGs were higher than those of eARGs during composting. iARG degradation was driven by the death and succession of potential hosts, primarily including gram-negative bacteria. Composting time advancement played a greater role in facilitating the microbial succession. High temperatures promoted bacterial death, which caused the release of iARGs and generation of eARGs, but continuous high temperature led to more eARG degradation. The dynamics of longer-term eARGs were more strongly affected by extracellular MGEs (eMGEs), and it is more likely that eARGs enter the environment synchronously with eMGEs and persist in the environment at lower abundances via eMGEs. Once eARGs re-enter bacteria, they may become more mobile and dangerous. This study provides insights for facilitating the removal of ARGs in fertilizer utilization.

Industrial-scale composting of swine manure with a novel additive-yellow phosphorus slag: Variation in maturity indicators, compost quality and phosphorus speciation

Composting experiment of swine manure, adding with yellow phosphorus slag(YPS) at 5% (w/w), was conducted in an industrial-scale reactor covered with semi-permeable membrane. During 27 days of composting, the changes in temperature, compost quality and phosphorus(P) speciation of products were monitored. Results indicated that the temperature of compost pile was sharply increased on day 2, and the thermophilic period lasted for 15 days. The dynamics in germination index(GI), pH, nutrient contents, etc. of products were in line with conventional composting process. For P distribution, the contents of total-P and citric acid extracted-P(CAP) of products were increased during composting, while that of Olsen-P was decreased. HCl extracted inorganic P(HCl-Pi), a slowly release fraction of P, was dominated in the product, which showed an increasing trend during the composting. These results suggest that the industrial-scale composting with novel YPS additive can be accomplished, and its product contains abundant slowly released P.

Reductions in abundances of intracellular and extracellular antibiotic resistance genes by SiO2 nanoparticles during composting driven by mobile genetic elements

Applying exogenous additives during the aerobic composting of livestock manure is effective for slowing down the spread of antibiotic resistance genes (ARGs) in the environment. Nanomaterials have received much attention because only low amounts need to be added and they have a high capacity for adsorbing pollutants. Intracellular ARGs (i-ARGs) and extracellular ARGs (e-ARGs) comprise the resistome in livestock manure but the effects of nanomaterials on the fates of these different fractions during composting are still unclear. Thus, we investigated the effects of adding SiO2 nanoparticles (SiO2NPs) at four levels (0 (CK), 0.5 (L), 1 (M), and 2 g/kg (H)) on i-ARGs, e-ARGs, and the bacterial community during composting. The results showed that i-ARGs represented the main fraction of ARGs during aerobic composting of swine manure, and their abundance was lowest under M. Compared with CK, M increased the removal rates of i-ARGs and e-ARGs by 17.9% and 100%, respectively. SiO2NPs enhanced the competition between ARGs hosts and non-hosts. M optimized the bacterial community by reducing the abundances of co-hosts (Clostridium_sensu_stricto_1, Terrisporobacter, and Turicibacter) of i-ARGs and e-ARGs (by 96.0% and 99.3%, respectively) and killing 49.9% of antibiotic-resistant bacteria. Horizontal gene transfer dominated by mobile genetic elements (MGEs) played a key role in the changes in the abundances of ARGs. i-intI1 and e-Tn916/1545 were key MGEs related closely to ARGs, and the maximum decreases of 52.8% and 100%, respectively, occurred under M, which mainly explained the decreased abundances of i-ARGs and e-ARGs. Our findings provide new insights into the distribution and main drivers of i-ARGs and e-ARGs, as well as demonstrating the possibility of adding 1 g/kg SiO2NPs to reduce the propagation of ARGs.

The environmental risk of antibiotic resistance genes from manure compost fertilizer gradually diminished during ryegrass planting

As one of the emerging pollutants in the environment, antibiotic resistance genes (ARGs) have attracted much attention. Composting is an effective way to reduce ARGs and the compost products were often used as soil amendments. However, the environmental risk of ARGs from compost products to soil and plants has not been well studied. Here, we assessed the environmental risk of ARGs from soil and ryegrass after applying manure composting. This study detected 21 different types of ARGs. Multidrug and tetracycline resistance genes were the most dominant ones, accounting for 39.2%/12.5% and 38.6%/11.6% in soil/ryegrass, respectively. This might be attributed to the decrease of Streptomyces, which is the potential host of multidrug and tetracycline ARGs. The environmental risk value, which was associated with mobile genetic elements (MGEs) and pathogens, increased in the soil and ryegrass, and return to the original level at the end of the growth cycle. The absolute environmental risk values of AH (high additive amount of the swine manure compost) and BH (high additive amount of the sheep manure compost) decreased by 0.0826 and 0.1505, respectively. The outcomes of this study revealed the environmental behavior and risk of ARGs transferring from compost to soil, and then entering into ryegrass, which is important to assess the environmental risk of compost and provide new insights into agricultural food safety.

Evaluation of a subtropical maize-rice rotation system maintained under long-term fertilizer inputs for sustainable intensification of agriculture

The impacts of long-term (1996–2019) fertilizer inputs on grain yield and edaphic factors of upland maize and wetland rice rotation system were assessed for sustainable intensification of agriculture. Subtropical field treatments included swine manure compost (CP), chemical fertilizer (CF, control), no fertilizer (CK, blank), inorganic N-amended CP (CPN1 and CPN2), peat (PN1) and green manure (GMN1). Maize exhibited a significantly increased yield trend under CF, GMN1 and CP-based inputs (CP, CPN1 and CPN2), whereas rice yield displayed a non-significant marginal improvement or negative result. Principal component analysis of edaphic factors revealed distinct clustering of CP-CPN1-CPN2, CF-GMN1-CK and PN1 samples during maize-rice rotation. CP-based inputs in particular improved OM, EC, microbial metabolism and nutrient availability during crop rotation. Pronounced soil microbial activity and Bacterial abundances were recorded during maize cultivation. In contrast, low aerobic metabolism coupled with high Bacterial and Archaeal species richness, diversity and evenness were found during rice cultivation. In conclusion, increasing maize yield trends observed under long-term CP-based inputs were on par with CF and GMN1 amendments that concurrently acidified soil. Numerically dominant aerobic Bacteria appear to drive nutrient recycling and promote maize grain yield, whereas metabolically lethargic diverse prokaryotes constrained nutrient turnover stagnating the rice yield.

Evaluation of the Impact of Activated Biochar-Manure Compost Pellet Fertilizer on Volatile Organic Compound Emissions and Heavy Metal Saturation.

For this experiment, pelletized activated biochar made of rice hullsor palm bark with swine manure compost was prepared to demonstrate the significant benefits of applying activated biochar-manure compost pellet fertilizer (ABMCP) inmitigating volatile organic compounds (VOCs), odor emission, and heavy metal saturation. Morphology and surface area analysis indicated that the activated rice hull biochar-manure compost pellet (ARP) had a significantly lower surface area, porous volume, and Fe content the activated palm biochar-manure compost pellet (APP). However, the ARP presented great potential to mitigate VOCs and odorant emissions. Our results indicated that the ARP reduced total reduced sulfur (TRS) and volatile fatty acids (VFAs) emissions by 69% and 93%, respectively. Heavy metals such as Pb, As, and Cd were not detected in the leachates fromthe ARP, APP, and swine manure compost. These results suggest that ABMCP can be a potential adsorbent to control VOCs and odorant emissions andpromote sustainable swine manure management and agricultural application.

Phylogenetic placement of thermophilic ammonium-tolerant bacteria and their distribution in various composts.

Previous studies isolated the thermophilic ammonium-tolerant (TAT) bacterium Bacillus sp. TAT105 that grew in composting swine manure with the assimilation of ammonium nitrogen and reduced ammonia emissions during composting. Those studies also investigated the potential for applications of TAT105 to composting. It was observed that the concentration of TAT bacteria, phylogenetically close to TAT105, increased during composting. The objectives of this study were to identify the phylogenetic placement of these TAT bacteria and investigate their distribution in various composts. The phylogenetic placement of TAT105 was examined based on the sequence of 16S ribosomal RNA gene. The genomic DNA homology between TAT105 and the type strains of bacterial species that were phylogenetically close to TAT105 were examined by DNA-DNA hybridization. Moreover, the tolerances of these strains to NH4Cl and NaCl were analyzed using a cultivation method. Concentrations of TAT bacteria in various composts were evaluated using an agar medium specific to TAT bacteria and polymerase chain reaction followed by restriction fragment length polymorphism analysis. TAT105 was most closely related to Bacillus thermolactis and Bacillus kokeshiiformis. Many variants of these species have been detected in various environments, including composts. The type strains of these species displayed TAT characteristics that were similar to those of TAT105. Among the composts examined in this study, TAT bacteria were detected at high concentrations (105 to 109 colony forming units per gram of dry matter) in most of the composts made from cattle manure, swine manure, bark, and excess sludge. TAT bacteria comprised B. thermolactis, B. kokeshiiformis, and their phylogenetically close relatives. They were considered to be adaptable to composting of some certain materials, and a favorable target for searching for strains with some useful function that could be applied to composting of these materials.

Three-dimensional printed bulking agents reduce antibiotic resistance genes in swine manure aerobic composting by regulating oxygen concentration to alter host microorganisms and mobile genetic elements

Antibiotic resistance genes (ARGs) in manure aerobic composting are a potential environmental pollutant. Therefore, reducing the abundance of ARGs is crucial. The effects of adding three-dimensional printed bulking agents (3DBAs) on ARGs in aerobic composting of swine manure were investigated in this study. Compared with the control group, 3DBAs with different addition dosages can greatest reduce the total ARGs by 5.98%, tetracycline resistance genes by 14.02%, macrolide resistance genes by 9.65%, and sulfonamide resistance genes by 20.59%. By further combining physicochemical parameters, host microorganisms, and mobile genetic elements (MGEs) for analysis, it was found that oxygen concentration was vital for ARGs reduction, and 3DBAs with regular porosity and uniform size indirectly regulate the activity of host microorganisms and MGEs abundance by changing the oxygen consumption, finally reducing vertical or horizontal ARGs transfer risks. Overall, 3DBAs addition is an effective strategy to reduce the abundance of ARGs in aerobic composting.

Effects of composting on the fate of doxycycline, microbial community, and antibiotic resistance genes in swine manure and broiler manure

Aerobic composting is an economical and effective technology that is widely used to treat animal manure. To study the fate of doxycycline (DOX), the microbial community, and antibiotic resistance genes (ARGs) during composting, aerobic composting of broiler manure and swine manure was carried out under natural environmental conditions. Aerobic composting effectively removed DOX (with a removal rate > 97%) and most ARGs from animal manure. The microbial diversity and the numbers of ARGs were higher in composted swine manure compared with composted broiler manure. The microbial community structure changed during composting, and the dominant phyla of broiler manure and swine manure changed from Firmicutes to Bacteroidetes and Proteobacteria, respectively. DOX changed the structure and relative abundance of the microbial community during composting, and the relative abundance of multidrug resistance genes and mobile genetic elements (MGEs) increased, which might lead to the risk of transmission of resistance in the environment. The C / N ratio, DOX concentration, Firmicutes, intl1, and intl2 were the key factors driving the change in ARGs during composting. These results help to reveal the effects of DOX on microbial communities, ARGs, and MGEs during composting and clarify the possible ways to reduce the risk of resistance gene transmission in the environment.

Fate of Florfenicol, Thiamphenicol, Antibiotic Resistance Genes During Composting of Swine Manure and Risk of Fertilization

Fate of Florfenicol, Thiamphenicol, Antibiotic Resistance Genes During Composting of Swine Manure and Risk of Fertilization

Ciprofloxacin Causes the Greatest Bacterial Community Variation in Swine Manure Composting

In this study, the influence of ciprofloxacin, chlorotetracycline, lincomycin, and sulfamethoxazole on the composition of the bacterial community structure was studied during aerobic composting with swine manure. Firmicutes (26.67%) and Chloroflexi (23.33%) were the most widely distributed phyla. Under all antibiotic treatments, the relative abundances of Bacillaceae, Streptosporangiaceae, Limnochordaceae, and Peptostreptococcaceae increased during the composting process. Moreover, norank_SBR1031, Planococcaceae, Thermomonosporaceae, Peptostreptococcaceae, Erysipelotrichaceae, Limnochordaceae, and Clostridiaceae_1 were the families showing the most significant differences across all treatments (p &amp;lt; 0.05). Principal co-ordinates analysis indicated that the family composition in the ciprofloxacin treatment significantly differed from the other treatments. The presence of ciprofloxacin increased both the abundance and diversity of the bacterial community (the Chao index changed from 588.44 to 680.17, and the Shannon index changed from 3.41 to 4.06) in the end of composting. Crocinitomicaceae dominated (relative abundance of 79.10%) among the unique families in the ciprofloxacin treatment. Network analysis indicated that ciprofloxacin altered the synergistic or competitive relationships between different families (norank_SBR1031 and Microscillaceae), leading to different bacterial community composition compared with other treatments. Further, a structural equation model showed that the C:N ratio was significantly negatively correlated with the bacterial community (λ = −0.869, p &amp;lt; 0.01), whereas pH showed a direct, significant positive relationship with the bacterial community (λ = 0.701, p &amp;lt; 0.01), especially in ciprofloxacin treatment. Overall, ciprofloxacin significantly influenced the physical and chemical properties of composting, altered the bacterial community structure. These findings have important implications for a better understanding of the effects of antibiotic types on bacterial community structure and the involved mechanisms during swine manure composting.