Evaluation of compost quality and the environmental effects of semipermeable membrane composting with poultry manure using sawdust or mushroom residue as the bulking agent.

Herein, the effects of different bulking agents (sawdust and mushroom residue), on compost quality and the environmental benefits of semipermeable film composting with poultry manure were investigated. The results show that composting with sawdust as the bulking agent resulted in greater efficiency and more cost benefits than composting with mushroom residue, and the cost of sawdust for treating an equal volume of manure was only 1/6 of that of mushroom residue. Additionally, lignin degradation and potential carbon emission reduction in the sawdust group were better than those in the mushroom residue group, and the lignin degradation efficiency of the bottom sample in the sawdust group was 48.57 %. Coupling between lignin degradation and potential carbon emission reduction was also closer in sawdust piles than in mushroom residue piles, and sawdust is more environmentally friendly. The abundance of key functional genes was higher at the bottom of each pile relative to the top and middle. Limnochordaceae, Lactobacillus and Enterococcus were the core microorganisms involved in coupling between lignin degradation and potential carbon emission reduction, and the coupled relationship was influenced by electric conductivity, ammonia nitrogen and total nitrogen in the compost piles. This study provides important data for supporting bulking agent selection in semipermeable film composting and for improving the composting process. The results have high value for compost production and process application.

Digital automation of transdermal drug delivery with high spatiotemporal resolution.

Transdermal drug delivery is of vital importance for medical treatments. However, user adherence to long-term repetitive drug delivery poses a grand challenge. Furthermore, the dynamic and unpredictable disease progression demands a pharmaceutical treatment that can be actively controlled in real-time to ensure medical precision and personalization. Here, we report a spatiotemporal on-demand patch (SOP) that integrates drug-loaded microneedles with biocompatible metallic membranes to enable electrically triggered active control of drug release. Precise control of drug release to targeted locations (<1 mm2), rapid drug release response to electrical triggers (<30 s), and multi-modal operation involving both drug release and electrical stimulation highlight the novelty. Solution-based fabrication ensures high customizability and scalability to tailor the SOP for various pharmaceutical needs. The wireless-powered and digital-controlled SOP demonstrates great promise in achieving full automation of drug delivery, improving user adherence while ensuring medical precision. Based on these characteristics, we utilized SOPs in sleep studies. We revealed that programmed release of exogenous melatonin from SOPs improve sleep of mice, indicating potential values for basic research and clinical treatments.

Effects of microplastics on functional genes related to CH4 and N2O metabolism in bacteriophages during manure composting and its planting applications.

Microplastics (MPs), as a new type of pollutant, widely exist in livestock and poultry breeding and agricultural soils. However, research on MPs pollution on greenhouse gas emissions in combined planting and breeding systems is lacking, especially from the perspective of phage horizontal gene transfer. Therefore, this paper explores the effects of MPs on functional genes related to CH4 and N2O metabolism in bacteriophages during manure composting and its planting applications. The results of the study indicated that the addition of MPs had an impact on both the physicochemical properties and microbial community structure of manure during the composting process and on the compost-applied rhizosphere soil of lactuca (Lactuca sativa). Specifically, on day 7 of composting, mcrA/pmoA and (nirS+nirK) levels in bacteria in the MP group significantly increased. Additionally, it was observed that the MP group had higher average temperatures during the high-temperature period of composting, which led to a rapid reduction in phages. However, the phage levels quickly recovered during the cooling period. Furthermore, the addition of MPs to the rhizosphere soil resulted in higher levels of nirK. These changes may affect greenhouse gas emissions.

The effect of manure-borne doxycycline combined with different types of oversized microplastic contamination layers on carbon and nitrogen metabolism in sandy loam.

The different forms and properties of microplastics (MPs) have different effects on the elemental cycles in soil ecosystems, and this is further complicated when the soil contains antibiotics; meanwhile, oversized microplastic (OMP) in soil is always ignored in studies of environmental behavior. In the context of antibiotic action, the effects of OMP on soil carbon (C) and nitrogen (N) cycling have rarely been explored. In this study, we created four types of oversized microplastic (thick fibers, thin fibers, large debris, and small debris) composite doxycycline (DOX) contamination layers (5-10 cm) in sandy loam, hoping to reveal the effects on soil C and N cycling and potential microbial mechanisms when exposed to the combination of manure-borne DOX and different types of OMP from the perspective of metagenomics in the longitudinal soil layer (0-30 cm). The results showed that all different forms of OMP, when combined with DOX, reduced the soil C content in each layer, but only reduced the soil N content in the upper layer of the OMP contamination layer. The microbial structure of the surface soil (0-10 cm) was more noteworthy than that of the deeper soil (10-30 cm). The genera Chryseolinea and Ohtaekwangia were key microbes involved in C and N cycling in the surface layer and regulated carbon fixation in photosynthetic organisms (K00134), carbon fixation pathways in prokaryotes (K00031), methane metabolism (K11212 and K14941), assimilatory nitrate reduction (K00367), and denitrification (K00376 and K04561). The present study is the first to reveal the potential microbial mechanism of C and N cycling under OMP combined with DOX in different layers, mainly the OMP contamination layer and its upper layer, and the OMP shape plays an important role in this process.

Sodium butyrate reduces ammonia production in the cecum of laying hens by regulating ammonia-producing bacteria.

Sodium butyrate is a commonly used feed additive and can reduce ammonia (NH3) emissions from laying hens, but the mechanism of this effect is unknown. In this study, the sodium butyrate and cecal content of Lohmann pink laying hens were measured, and in vitro fermentation experiments and NH3-producing bacteria coculture experiments were carried out to explore the relationship between NH3 emissions and its associated microbiota metabolism. Sodium butyrate was found to significantly reduce NH3 emission from the cecal microbial fermentation of Lohmann pink laying hens (P < 0.05). The concentration of NO3--N in the fermentation broth of the sodium butyrate-supplemented group increased significantly, and the concentration of NH4+-N decreased significantly (P < 0.05). Moreover, sodium butyrate significantly reduced the abundance of harmful bacteria and increased the abundance of beneficial bacteria in the cecum. The culturable NH3-producing bacteria consisted mainly of Escherichia and Shigella, such as Escherichia fergusonii, Escherichia marmotae and Shigella flexnerii. Among them, E. fergusonii had the highest potential for NH3 production. The coculture experiment showed that sodium butyrate can significantly downregulate the expression of the lpdA, sdaA, gcvP, gcvH and gcvT genes of E. fergusonii (P < 0.05), thus reducing the NH3 emission produced by the bacteria during metabolism. In general, sodium butyrate regulated NH3-producing bacteria to reduce NH3 production in the cecum of laying hens. These results are of great significance for NH3 emission reduction in the layer breeding industry and for future research.

Effects of the oversized microplastic pollution layer on soil aggregates and organic carbon at different soil depths.

Soil aggregates (SAs) are the main site for soil organic carbon (SOC) fixation, and land plastic pollution is increasingly causing many soil problems. The effects of plastic on SAs and SOC seem to be significant, but there is still a lack of relevant research. This study investigated the effects of the "plastic contamination layer" (PCL) formed by the microplastic precursors (namely, oversized microplastics (OMPs)) on the content and properties of SAs of different particle sizes at different soil depths. The results showed that the PCL had an effect on SAs of different sizes at different depths: Compared with the control group, PCL mainly increased the content of SAs in 0-5 cm soil depth, about 28.08 mg macroaggregates, 13.79 mg microaggregates and 59.82 mg silt and clay aggregates per gram of soil. The presence of the PCL mainly down-regulates the organic carbon (OC) content in 0-5 cm macroaggregates, which is about 9.59 g/kg, the OC content in 10-20 cm microaggregates, which is about 16.41 g/kg, and the OC content in 0-5 cm silt and clay aggregates, which is about 4.16 g /kg, downregulated the expression of the key carbon metabolism genes (CMGs) coxL, and inhibited the contribution of the potential CMGs host bacteria Sphaerimonospora and Bacteroides to soil organic matter. This paper emphasizes that the presence of PCL reduced SOC sequestration.

Skin-inspired, sensory robots for electronic implants.

Living organisms with motor and sensor units integrated seamlessly demonstrate effective adaptation to dynamically changing environments. Drawing inspiration from cohesive integration of skeletal muscles and sensory skins in these organisms, we present a design strategy of soft robots, primarily consisting of an electronic skin (e-skin) and an artificial muscle, that naturally couples multifunctional sensing and on-demand actuation in a biocompatible platform. We introduce an in situ solution-based method to create an e-skin layer with diverse sensing materials (e.g., silver nanowires, reduced graphene oxide, MXene, and conductive polymers) incorporated within a polymer matrix (e.g., polyimide), imitating complex skin receptors to perceive various stimuli. Biomimicry designs (e.g., starfish and chiral seedpods) of the robots enable various motions (e.g., bending, expanding, and twisting) on demand and realize good fixation and stress-free contact with tissues. Furthermore, integration of a battery-free wireless module into these robots enables operation and communication without tethering, thus enhancing the safety and biocompatibility as minimally invasive implants. Demonstrations range from a robotic cuff encircling a blood vessel for detecting blood pressure, to a robotic gripper holding onto a bladder for tracking bladder volume, an ingestible robot residing inside stomach for pH sensing and on-site drug delivery, and a robotic patch wrapping onto a beating heart for quantifying cardiac contractility, temperature and applying cardiac pacing, highlighting the application versatilities and potentials of the nature-inspired soft robots. Our designs establish a universal strategy with a broad range of sensing and responsive materials, to form integrated soft robots for medical technology and beyond.

Transmission of tetracycline resistance genes and microbiomes from manure-borne black soldier fly larvae frass to rhizosphere soil and pakchoi endophytes.

Manure treatment with black soldier fly larvae (BSFL) and BSFL frass application in crop land is a sustainable strategy; however, whether residual antibiotic resistance genes (ARGs) and their transmission risk are related to the manure BSFL treatment process is still unknown. In this paper, the effect of BSFL addition density on residual tetracycline resistance genes (TRGs) and transmission from frass to pakchoi was determined. The results showed that BSFL frass can provide sufficient nutrients for growth, improve the economic value of pakchoi, and reduce the risk of transmission of TRGs in chicken manure regardless of BSFL density. The potential hosts of the TRGs we detected were found in BSFL frass (Oblitimonas and Tissierella), rhizosphere soil (Mortierella and Fermentimonas), and pakchoi endophytes (Roseomonas). The present study concluded that BSFL frass produced by adding 100 BSFL per 100 g of chicken manure has the advantages of high value and low risk. These findings will provide important strategic guidance for animal manure disposal and theoretical support for preventing the transmission of TRGs in BSFL applications.

The fate of antibiotic resistance genes and their association with bacterial and archaeal communities during advanced treatment of pig farm wastewater.

Advanced wastewater treatment plants are widely used in most large-scale pig farms in southern China. However, the fate of antibiotic resistance genes (ARGs) and their association with bacterial and archaeal communities during advanced wastewater treatment remain unclear. In this study, the profiles of ARGs in typical advanced wastewater treatment plants were surveyed using metagenomic analysis. The results showed that 279- 326 different subtypes of ARGs were detected in raw wastewater, with a total abundance of 5.98 ± 0.48 copies per bacterial cell. During the advanced wastewater treatment, the abundance and number of ARGs were significantly reduced. Microbial communities (bacteria and archaea) contributed the most to the variation in ARG abundance and composition (PCA axis_1), accounting for 10.8 % and 15.7 %, respectively, followed by mobile genetic elements (MGEs) and physicochemical factors. Special attention should be given to potential pathogenic bacteria such as Escherichia, Streptococcus, Enterococcus and Staphylococcus and archaea such as Methanocorpusculum, Candidatus Methanoplasma and Candidatus Methanomethylophilus, which were important potential ARG hosts. Bacterial communities may indirectly affect ARG variation by affecting archaeal communities. These findings indicated that ARG levels in pig farm wastewater can be effectively reduced during advanced treatment and highlighted the important role played by archaea, which should not be ignored.

Cyclic AMP and biofilms reveal the synergistic proliferation strategy of Pseudomonas aeruginosa and Escherichia coli under the costimulation of high concentrations of microplastics and enrofloxacin.

Microplastics (MPs) provide attachment sites for biofilm formation of microorganisms, which can promote their resistance to environmental stress has been proved. However, the effect of MPs on synergy survival among microorganisms under antibiotic stress remains unclear. In the present study, the proliferation of Escherichia coli and Pseudomonas aeruginosa was assessed under enrofloxacin stress with the influence of MPs. Here, MPs reduced the growth speed of E. coli and enhanced that of P. aeruginosa, especially at 12 h, but the final value of OD600 and CFU of both bacteria not be influenced. E. coli was enrofloxacin sensitive (MIC = 0.25 µg/mL), and a high MP concentration in the presence of enrofloxacin notably enhanced the biofilm formation ability of P. aeruginosa, but proliferation decreased. In the coculture system, the proliferation of E. coli (increased 1.42-fold) and P. aeruginosa (increased 1.06-fold) both increased under enrofloxacin stress (0.25 µg/mL) with high-concentration MP addition. P. aeruginosa may provide the biofilm matrix for E. coli to resist the stress of enrofloxacin. The high concentration of cyclic AMP secreted by E. coli may slightly inhibited biofilm formation, leading to a decrease in the fitness cost of P. aeruginosa; thus, the proliferation of P. aeruginosa increased. The present study is the first to show that MP combined with antibiotics stimulates the metabolic cooperation of bacteria to promote proliferation.

Metagenomic assembly reveals the circadian oscillations of the microbiome and antibiotic resistance genes in a model of laying hens.

The increasing risks of antibiotic resistance genes (ARGs) in livestock feces have attracted global attention. However, how the rhythmic activity of ARGs changes in fecal microbiota remains largely unclear. In our study, we collected 52 fresh fecal samples every 6 h over 72 h from laying hens and characterized circadian oscillations of bacteria and ARGs using an approach based on assembled metagenome shotgun sequencing. We found that 14% of commensal bacterial taxonomic units fluctuated over 24 h. A total of 33 out of 281 ARGs and 17 of 574 mobile genetic elements (MGEs) featured rhythmic patterns in feces. lnuC and ANT(6)H-lb were the two most abundant ARGs with circadian oscillation identified from feces, and they increased during the day and decreased at night. Acetate, butyrate, propionate, and 78 out of 392 MetaCyc pathways relating to short-chain fatty acid (SCFA) metabolism featured circadian oscillations. Assessment of the above ARG-other element connections revealed that 17 ARGs presented strong correlations with 7 MGEs, and 2 SCFAs (acetate and propanoate) and bacterial species in feces. Structural equation model (SEM) analysis showed that ARGs were directly affected by microbial ß-diversity and MGEs. These results showed a comprehensive map of ARGs over 24 h and revealed circadian oscillations of ARGs, which are influenced by key bacterial species, MGEs, and metabolites. Together, our findings advance comprehension of circadian oscillations of ARGs in the fecal microbiota and provide a reference for ARGs control and management.

Porcine gut microbiota in mediating host metabolic adaptation to cold stress.

The gut microbiota plays a key role in host metabolic thermogenesis by activating UCP1 and increasing the browning process of white adipose tissue (WAT), especially in cold environments. However, the crosstalk between the gut microbiota and the host, which lacks functional UCP1, making them susceptible to cold stress, has rarely been illustrated. We used male piglets as a model to evaluate the host response to cold stress via the gut microbiota (four groups: room temperature group, n = 5; cold stress group, n = 5; cold stress group with antibiotics, n = 5; room temperature group with antibiotics, n = 3). We found that host thermogenesis and insulin resistance increased the levels of serum metabolites such as glycocholic acid (GCA) and glycochenodeoxycholate acid (GCDCA) and altered the compositions and functions of the cecal microbiota under cold stress. The gut microbiota was characterized by increased levels of Ruminococcaceae, Prevotellaceae, and Muribaculaceae under cold stress. We found that piglets subjected to cold stress had increased expression of genes related to bile acid and short-chain fatty acid (SCFA) metabolism in their liver and fat lipolysis genes in their fat. In addition, the fat lipolysis genes CLPS, PNLIPRP1, CPT1B, and UCP3 were significantly increased in the fat of piglets under cold stress. However, the use of antibiotics showed a weakened or strengthened cold tolerance phenotype, indicating that the gut microbiota plays important role in host thermogenesis. Our results demonstrate that the gut microbiota-blood-liver and fat axis may regulate thermogenesis during cold acclimation in piglets.

A sustainable and economic strategy to reduce risk antibiotic resistance genes during poultry manure bioconversion by black soldier fly Hermetia illucens larvae: Larval density adjustment.

Black soldier fly (Hermetia illucens) larvae (BSFL) are common insects that are known for bioconversion of organic waste into a sustainable utilization resource. However, a strategy to increase antibiotic resistance gene (ARG) elimination in sustainable and economic ways through BSFL is lacking. In the present study, different larval densities were employed to assess the mcr-1 and tetX elimination abilities, and potential mechanisms were investigated. The application and economic value of each larval density were also analyzed. The results showed that the 100 larvae cultured in 100 g of manure group had the best density because the comprehensive disadvantage evaluation ratio was the lowest (14.97%, good bioconversion manure quality, low ARG deposition risk and reasonable larvae input cost). Further investigation showed that mcr-1 could be significantly decreased by BSFL bioconversion (4.42 ×107 copies/g reduced to 4.79 ×106-2.14 ×105 copies/g)(P＜0.05); however, mcr-1 was increasingly deposited in the larval gut with increasing larval density. The tetX abundance was stabilized by BSFL bioconversion, except that the abundance at the lowest larval density increased (1.22 ×1010 copies/g increase, 34-fold). Escherichia was the host of mcr-1 and tetX in all samples, especially in fresh manure; Alcaligenes was the host of tetX in bioconversion manure; and the abundance of Alcaligenes was highly correlated with the pH of bioconversion manure. The pH of bioconversion manure was extremely correlated with the density of larvae. Klebsiella and Providencia were both hosts of tetX in the BSF larval gut, and Providencia was also the host of mcr-1 in the BSF larval gut. The density of larvae influenced the bioconversion manure quality and caused the ARG host abundance to change to control the abundance of ARGs, suggesting that larval density adjustment was a useful strategy to manage the ARG risk during BSFL manure bioconversion.

Abundance, diversity and diffusion of antibiotic resistance genes in cat feces and dog feces.

The ARG profiles in pet feces, such as cat and dog feces, and their potential threat to environmental safety are still unclear. In this study, ARGs in 45 cat and 28 dog fecal samples were detected, and a diffusion experiment was performed to assess the risk of ARGs diffusion into the air. The results showed that the abundances of ARGs in cat feces and dog feces were high, and the abundance in dog feces (0.89 ± 0.17 copies/bacterial cell) was significantly higher than that in cat feces (0.46 ± 0.09 copies/bacterial cell) (P < 0.05). The bacterial community, especially Firmicutes and Desulfobacterota in cat feces, and Proteobacteria in dog feces, was the main factor affecting the variation in the ARG profiles, contributing to 31.6% and 32.4% of the variation in cat feces and dog feces, respectively. Physicochemical factors (especially NH4+-N) and age also indirectly affected the variation in the ARG profiles by affecting the bacterial community. In addition, the ARGs in cat feces and dog feces diffused into the air, but there was no evidence that this diffusion posed a threat to environmental safety and human health. These results can provide reference data for healthy animal breeding and the prevention and control of ARG pollution.

Breed differences in the expression levels of gga-miR-222a in laying hens influenced H2S production by regulating methionine synthase genes in gut bacteria.

BACKGROUND: The microbiota in the cecum of laying hens is crucial for host digestion, metabolism, and odor gas production. The results of recent studies have suggested that host microRNAs (miRNAs) can regulate gene expression of the gut microbiota. In the present study, the expression profiles of host-derived miRNAs in the cecal content of two laying hen breeds; Hy-line Gray and Lohmann Pink, which have dissimilar H2S production, were characterized; and their effects on H2S production by regulating the expression of gut microbiota-associated genes were demonstrated. RESULTS: The differential expression of microbial serine O-acetyltransferase, methionine synthase, aspartate aminotransferase, methionine-gamma-lyase, and adenylylsulfate kinase between the two hen breeds resulted in lower H2S production in the Hy-line hens. The results also revealed the presence of miRNA exosomes in the cecal content of laying hens, and an analysis of potential miRNA-target relationships between 9 differentially expressed miRNAs and 9 differentially expressed microbial genes related to H2S production identified two methionine synthase genes, Odosp_3416 and BF9343_2953, that are targeted by gga-miR-222a. Interestingly, in vitro fermentation results showed that gga-miR-222a upregulates the expression of these genes, which increased methionine concentrations but decreased H2S production and soluble sulfide concentrations, indicating the potential of host-derived gga-miR-222a to reduce H2S emission in laying hens. CONCLUSION: The findings of the present study reveal both a physiological role by which miRNAs shape the cecal microbiota of laying hens and a strategy to use host miRNAs to manipulate the microbiome and actively express key microbial genes to reduce H2S emissions and breed environmentally friendly laying hens. Video Abstract.

Elimination and analysis of mcr-1 and blaNDM-1 in different composting pile layers under semipermeable membrane composting with copper-contaminated poultry manure.

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.

Occurrence of microplastic in livestock and poultry manure in South China.

Microplastic (MP) contamination in soil has attracted much attention, and increasing evidence suggests that MPs can accumulate in agricultural soils through fertilization by compost. In addition, the most common raw materials for composting are livestock and poultry manure wastes. Because the presence of MPs may threaten the safe utilization of fertilizers composted by livestock and poultry wastes during crop planting, it is necessary to understand the contamination risk of MPs present in livestock and poultry manure. In this study, the distribution of MPs in 19 livestock and poultry farms with 3 different species was investigated by using FTIR microscopy. A total of 115 items manure MPs and 18 items feed MPs were identified as PP and PE types dominated by colorful fragments and fibers. Furthermore, after comparing the compositions of plastic products used in the feeding process, we proposed two transport pathways for MP pollution in manure and one potential transport pathway in feeds. Our result proved that the application of swine and poultry manure directly could be a new route of MPs in agricultural soil, furthermore, the presence of MPs could threaten the safety of resource utilization in agricultural soil by using swine and poultry manure for manure potentially. Not, only that, our study also provided a reference for the remediation of MP-contaminated soil.

Bacillus coagulans R11 consumption influenced the abundances of cecum antibiotic resistance genes in lead-exposed laying hens.

Bacillus coagulans is regarded as a clean, safe and helpful probiotic additive in the production of livestock and poultry breeds. Some studies have also shown that Bacillus coagulans can adsorb heavy metals in water, even in the gut of animals. However, whether Bacillus coagulans feeding influences antibiotic resistance gene (ARG) abundance in the gut of lead-exposed laying hens is unknown. To better apply such probiotics in the breeding industry, the present study employed Bacillus coagulans R11 and laying hens in model experiments to test ARG changes in the cecum of laying hens under lead exposure and B. coagulans R11 feeding. The results showed that there was the trend for ARG abundance decreasing in feeding B. coagulans R11 without lead exposure to laying hens in the cecum; however, feeding B. coagulans R11 to laying hens exposed to lead obviously increased the abundances of aminoglycoside and chloramphenicol ARGs. Further experiment found that hydroquinone, dodecanedioic acid, gibberellin A14, alpha-solanine, jasmonic acid and chitin were involved in the abundances of ARGs in the cecum, in addition the abundances of these compounds were also significantly enhanced by lead exposure or combination effects of lead and B. coagulans R11. As a result, the ARG hazards increased with feeding B. coagulans R11 to laying hens exposed to lead, and the key compounds which influenced by the combination effects of lead and B. coagulans R11 might influence the ARGs abundance.

A novel method for extraction of polypropylene microplastics in swine manure.

With the development of modern industry and agriculture, plentiful microplastics (MPs) were produced as a result of the abuse of plastic. The widespread presence of MPs in soils has caused coastal ecological environment pollution. Previous research has shown that fertilizer is one pathway for the entry of MPs into agricultural soils. Meanwhile, livestock manure is a major fertilizer for crops, and the application of livestock manure compost creates a potential pathway for MPs to enter soils. Thus, MPs may exist in livestock manure from the process of livestock breeding and ultimately contaminate agricultural soils. Based on the increasing attention to MP pollution, manure-born MPs will attract more interest in the future. Thus, the present study compares the extraction effects of centrifugation with fractional distillation, and an improved method is introduced to extract polypropylene (PP) from different types of swine manure. The numbers of particles and fibers were determined using a camera (MS60) connected to a stereomicroscope (Mshot MZ62), and the results showed that the recovery rate of plastic particles in swine manure based on different added numbers ranged from 71.43% ± 8.36 to 96.67% ± 3.33 with the centrifugation method, and only 31.11% ± 10.56 to 43.33% ± 12.56 using fractional distilling. The recovery rate for fibers was generally higher than for particles, especially using centrifugation, and ranged from 95.67% ± 1.58 to 100% ± 0, while the rate of fiber recovery using fractional distillation ranged from 39.44% ± 10.66 to 39.44 ± 10.66. The results of recovery rates using the two methods show that the effect of extraction by centrifugation is superior to the method of fractional distillation, with a recovery rate of approximately 100% for fibers and 90% for particles. The recovery number of microplastics evaluated with a line regression model was acceptable. Graphical abstract.

Profiles of bacteria/phage-comediated ARGs in pig farm wastewater treatment plants in China: Association with mobile genetic elements, bacterial communities and environmental factors.

In this study, the profiles of bacteria/phage-comediated antibiotic resistance genes (b/pARGs) were monitored in water samples collected from 45 pig farm wastewater treatment plants (WWTPs) in seven different regions of China. We found that 8 major types and 112 subtypes of b/pARGs were detected in all the water samples, and the detected number ranged from 53 to 92. The absolute abundances of bARGs and pARGs in the influent were as high as 109 copies/mL and 106 copies/mL, respectively. Anaerobic anoxic/oxic (AAO) and anaerobic short-cut nitrification/denitrification (ASND) treatment plants can effectively reduce the absolute abundance and amount of b/pARGs. Anaerobic treatment plants cannot reduce the absolute abundance of pARGs, and even increase the amount of pARGs. Mobile genetic elements (MGEs), bacterial communities and environmental factors were important factors impacting the b/pARG profile. Among these factors, the bacterial community was the major driver that impacted the bARG profile, while bacterial community and MGEs were the major codrivers impacting the pARG profile. This study was the first to investigate the profiles of b/pARGs in pig farm WWTPs in China on such a large scale, providing a reference for the prevention and control of ARG pollution in agricultural environments.