Variations in antibiotic resistance genes and removal mechanisms induced by C/N ratio of substrate during composting. - Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
691801.0000Variations in antibiotic resistance genes and removal mechanisms induced by C/N ratio of substrate during composting. For a comprehensive insight into the potential mechanism of the removal of antibiotic resistance genes (ARGs) removal induced by initial substrates during composting, we tracked the dynamics of physicochemical properties, bacterial community composition, fungal community composition, the relative abundance of ARGs and mobile genetic genes (MGEs) during reed straw and cow manure composting with different carbon to nitrogen ratio. The results showed that the successive bacterial communities were mainly characterized by the dynamic balance between Firmicutes and Actinobacteria, while the fungal communities were composed of Ascomycota. During composting, the interactions between bacteria and fungi were mainly negative. After composting, the removal efficiency of ARGs in compost treatment with C/N ≈ 26 (LL) was higher than that in compost treatment with C/N ≈ 35 (HL), while MGEs were completely degraded in HL and enriched by 2.3% in LL. The large reduction in the relative abundance of ARGs was possibly due to a decrease in the potential host bacterial genera, such as Advenella, Tepidimicrobium, Proteiniphilum, Acinetobacter, Pseudomonas, Flavobacteria and Arcbacter. Partial least-squares path modeling (PLS-PM) revealed that the succession of bacterial communities played a more important role than MGEs in ARGs removal, while indirect factors of the fungal communities altered the profile of ARGs by affecting the bacterial communities. Both direct and indirect factors were affected by composting treatments. This study provides insights into the role of fungal communities in affecting ARGs and highlights the role of different composting treatments with different carbon to nitrogen ration on the underlying mechanism of ARGs removal.202134375241
691910.9999Enhanced removal of antibiotic resistance genes during chicken manure composting after combined inoculation of Bacillus subtilis with biochar. This study explored the combined effects of Bacillus subtilis inoculation with biochar on the evolution of bacterial communities, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) during the composting of chicken manure. The results showed that B. subtilis inoculation combined with biochar increased bacterial abundance and diversity as well as prolonged the compost thermophilic period. Promoted organic matter biodegradation and facilitated the organic waste compost humification process, reduced the proliferation of ARGs by altering the bacterial composition. Firmicutes and Actinobacteriota were the main resistant bacteria related to ARGs and MGEs. The decrease in ARGs and MGEs was associated with the reduction in the abundance of related host bacteria. Compost inoculation with B. subtilis and the addition of biochar could promote nutrient transformation, reduce the increase in ARGs and MGEs, and increase the abundance of beneficial soil taxa.202437778803
754820.9998Maturity phase is crucial for removing antibiotic resistance genes during composting: novel insights into dissolved organic matter-microbial symbiosis system. Composting is widely regarded as an effective method for reducing antibiotic resistance genes (ARGs) in livestock and poultry manure. However, the critical mechanisms of ARGs in different composting phase are still unclear. In this study, normal composting and two types of rapid composting (without mature phase) were used to analyze the removal of ARGs and the succession of dissolved organic matter (DOM). Compared to normal composting, rapid composting reactivated tetracyclines, sulfonamide, and quinolones resistance genes during the maturation phase and reduced the total ARGs removal rates by 45.58 %-57.87 %. Humus-like components could inhibit the proliferation of ARGs, and the enrichment of protein-like components increased abundances of Pusillimonas, Persicitalea, and Pseudomonas, indirectly reducing the removal. This study is the first to demonstrate the contribution of DOM and microbial community to ARGs removal, emphasizing the importance of the maturation phase for ARGs elimination. This research provides guidance for producing safe compost products.202540311709
691530.9998Industrial-scale aerobic composting of livestock manures with the addition of biochar: Variation of bacterial community and antibiotic resistance genes caused by various composting stages. The presence of large amounts of antibiotic resistance genes (ARGs) in livestock manures poses an impending, tough safety risk to ecosystems. To investigate more comprehensively the mechanisms of ARGs removal from industrial-scale composting of livestock manure based on biochar addition, we tracked the dynamics of bacterial community and ARGs at various stages of aerobic composting of livestock manures with 10% biochar. There were no significant effects of biochar on the bacterial community and the profiles of ARGs. During aerobic composting, the relative abundance of ARGs and mobile genetic elements (MGEs) showed overall trends of decreasing and then increasing. The key factor driving the dynamics of ARGs was bacterial community composition, and the potential hosts of ARGs were Caldicoprobacter, Tepidimicrobium, Ignatzschineria, Pseudogracilibacillus, Actinomadura, Flavobacterium and Planifilum. The retention of the thermophilic bacteria and the repopulation of the initial bacteria were the dominant reasons for the increase in ARGs at maturation stage. Additionally, among the MGEs, the relative abundance of transposon gene was substantially removed, while the integron genes remained at high relative abundance. Our results highlighted that the suitability of biochar addition to industrial-scale aerobic composting needs to be further explored and that effective measures are needed to prevent the increase of ARGs content on maturation stage.202236162559
691640.9998Mobile genetic elements in potential host microorganisms are the key hindrance for the removal of antibiotic resistance genes in industrial-scale composting with municipal solid waste. During the municipal solid waste (MSW) composting, antibiotic resistance genes (ARGs) could be one of the concerns to hinder the application of MSW composting. However, the understanding of enrichment and dissemination of ARGs during the industrial-scale composting is still not clear. Hence, this study aimed to investigate the ARG distributions at different stages in an industrial-scale MSW composting plant. Seven target ARGs and four target mobile genetic elements (MGEs) and bacterial communities were investigated. The abundances of ARGs and MGEs increased during two aerobic thermophilic stages, but they decreased in most ARGs and MGEs after composting. Network analysis showed that potential host bacteria of ARGs were mainly Firmicutes and Actinobacteria. The reduction of potential host bacteria was important to remove ARGs. MGEs were an important factor hindering ARG removal. Water-extractable S and pH were two main physicochemical factors in the changes of microbial community and the abundance of ARGs.202031962245
692950.9998Root exudates regulate soil antibiotic resistance genes via rhizosphere microbes under long-term fertilization. Organic fertilizer application promotes the prevalence of antibiotic resistance genes (ARGs), yet the factors driving temporal differences in ARG abundance under long-term organic fertilizer application remain unclear. This study investigated the temporal dynamics of ARG diversity and abundance in both bulk and rhizosphere soils over 17 years (2003-2019), and explored microbial evolution strategies, ARG hosts succession and the influence of root exudates on ARGs regulation. The results showed that the ARGs abundance in rhizosphere soil was lower than that in bulk soil under long-term fertilization, and ARGs abundance exhibited a decrease and then remained stable in rhizosphere soil over time. There was a strong association between host bacteria and dominant ARGs (p < 0.05). Structural equations demonstrated that bacterial community had a most pronounced influence on ARGs (p < 0.05), and metabolites exhibited an important mediation effect on bacterial community (p < 0.05), thereby impacting ARGs. The metabolome analysis evidenced that significant correlations were found between defensive root exudates and most ARGs abundance (p < 0.05), like, luteolin-7-glucoside was negatively correlated with tetA(58). These findings provide deeper insights into the dynamics of soil ARGs under long-term fertilization, and identify critical factors that influence ARGs colonization in soils, providing support for controlling the spread of ARGs in agriculture soils.202539700687
692060.9998Dynamics and key drivers of antibiotic resistance genes during aerobic composting amended with plant-derived and animal manure-derived biochars. Plant-derived and animal manure-derived biochars have been used to improve the quality of compost but the differences in their effects on antibiotic resistance genes (ARGs) during composting are unclear. This study selected two types of biochar (RB and PB) produced from abundant agricultural waste to be added to the compost. Adding plant-derived RB performed better in ARGs, mobile genetic elements, and human pathogenic bacteria removal during aerobic composting, whereas adding manure-derived PB even increased ARGs abundance. Vertical gene transfer was possibly the key mechanism for persistent ARGs, and easily removed ARGs were regulated by horizontal and vertical gene transfer. Adding plant-derived RB reduced the abundances of persistent ARG hosts (e.g., Pseudomonas and Longispora) and ARG-related metabolic pathways and genes. The higher nitrogen content of manure-derived PB may have promoted the proliferation of ARG hosts. Overall, adding manure-derived biochar during composting may not be the optimal option for eliminating ARGs.202235487450
859070.9998Metagenomic insights into role of red mud in regulating fate of compost antibiotic resistance genes mediated by both direct and indirect ways. In this study, the amendment of red mud (RM) in dairy manure composting on the fate of antibiotic resistance genes (ARGs) by both direct (bacteria community, mobile genetic elements and quorum sensing) and indirect ways (environmental factors and antibiotics) was analyzed. The results showed that RM reduced the total relative abundances of 10 ARGs and 4 mobile genetic elements (MGEs). And the relative abundances of total ARGs and MGEs decreased by 53.48% and 22.30% in T (with RM added) on day 47 compared with day 0. Meanwhile, the modification of RM significantly increased the abundance of lsrK, pvdQ and ahlD in quorum quenching (QQ) and decreased the abundance of luxS in quorum sensing (QS) (P < 0.05), thereby attenuating the intercellular genes frequency of communication. The microbial community and network analysis showed that 25 potential hosts of ARGs were mainly related to Firmicutes, Proteobacteria and Actinobacteria. Redundancy analysis (RDA) and structural equation model (SEM) further indicated that RM altered microbial community structure by regulating antibiotic content and environmental factors (temperature, pH, moisture content and organic matter content), which then affected horizontal gene transfer (HGT) in ARGs mediated by QS and MGEs. These results provide new insights into the dissemination mechanism and removal of ARGs in composting process.202336462475
858980.9998Impacts of microplastic type on the fate of antibiotic resistance genes and horizontal gene transfer mechanism during anaerobic digestion. Microplastics (MPs) and antibiotic resistance genes (ARGs) are important pollutants in waste activated sludge (WAS), but their interactions during anaerobic digestion (AD) still need to be further explored. This study investigated variations in ARGs, mobile genetic elements (MGEs), and host bacteria during AD under the pressure of polyamide (PA), polyethylene (PE), and polypropylene (PP). The results showed that the MPs increased methane production by 11.7-35.5%, and decreased ARG abundance by 5.6-24.6%. Correlation analysis showed that the decrease of MGEs (plasmid, prophage, etc.) promoted the decrease of the abundance of multidrug, aminoglycoside and tetracycline resistance genes. Metagenomic annotation revealed that the reduction of key host bacteria (Arenimonas, Lautropia, etc.) reduced the abundance of major ARGs (rsmA, rpoB2, etc.). Moreover, PP MPs contributed to a reduction in the abundance of functional genes related to the production of reactive oxygen species, ATP synthesis, and cell membrane permeability, which was conducive to reducing the potential for horizontal gene transfer of ARGs. These findings provide insights into the treatment of organic waste containing MPs.202438772228
691790.9997Response characteristics of antibiotic resistance genes and bacterial communities during agricultural waste composting: Focusing on biogas residue combined with biochar amendments. This research investigated biogas residue and biochar addition on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and changes in bacterial community during agricultural waste composting. Sequencing technique investigated bacterial community structure and ARGs, MGEs changes. Correlations among physicochemical factors, ARGs, MGEs, and bacterial community structure were determined using redundancy analysis. Results confirmed that biochar and biogas residue amendments effectively lowered the contents of ARGs and MGEs. The main ARGs detected was sul1. Proteobacteria and Firmicutes were the main host bacteria strongly associated with the dissemination of ARGs. The dynamic characteristics of the bacterial community were strongly correlated with pile temperature and pH (P < 0.05). Redundancy and network analysis revealed that nitrate, intI1, and Firmicutes mainly affected the in ARGs changes. Therefore, regulating these key variables would effectively suppress the ARGs spread and risk of compost use.202336657587
8094100.9997Additive quality influences the reservoir of antibiotic resistance genes during chicken manure composting. Aerobic composting is commonly used to dispose livestock manure and is an efficient way to reduce antibiotic resistance genes (ARGs). Here, the effects of different quality substrates on the fate of ARGs were assessed during manure composting. Results showed that the total relative abundances of ARGs and intI1 in additive treatments were lower than that in control, and high quality treatment with low C/N ratio and lignin significantly decreased the relative abundance of tetW, ermB, ermC, sul1 and sul2 at the end of composting. Additionally, higher quality treatment reduced the relative abundances of some pathogens such as Actinomadura and Pusillimonas, and some thermotolerant degrading-related bacteria comprising Pseudogracilibacillus and Sinibacillus on day 42, probably owing to the change of composting properties in piles. Structural equation models (SEMs) further verified that the physiochemical properties of composting were the dominant contributor to the variations in ARGs and they could also indirectly impact ARGs by influencing bacterial community and the abundance of intI1. Overall, these findings indicated that additives with high quality reduced the reservoir of antibiotic resistance genes of livestock manure compost.202134139628
6913110.9997Antibiotic resistance genes link to nitrogen removal potential via co-hosting preference for denitrification genes in a subtropical estuary. Estuaries are important sinks for antibiotic resistance genes (ARGs) and hotspots of nitrogen cycling. However, the interactions between nitrogen cycling functional genes (NCGs) and ARGs in estuaries remain poorly understood. This study employed metagenomic sequencing to explore potential interactions between nitrogen, ARGs, and microbial-mediated nitrogen cycling processes in estuarine waters. Results showed beta-lactam was the predominant subtype of ARGs (407 species), and sul1 exhibited the highest relative abundance (4.11 %). Nitrogen was the important factor driving spatiotemporal variation of ARGs, promoting their proliferation and dispersal by enhancing microbial growth and reproduction. Network analysis revealed wide and complex correlations between ARGs and NCGs. Nitrate-reducing bacteria were the main hosts of ARGs, and the greatest number of potential hosts were those involved in assimilatory nitrate reduction to ammonium (17.44 %), dissimilatory nitrate reduction to nitrite (16.59 %), and denitrification (15.71 %). Compared with dissimilatory nitrite reduction to ammonium genes, ARGs prefer to form co-hosting relationships with denitrification genes, indicating that ARGs had a stronger effect on the nitrogen removal potential than on the nitrogen retention potential. This study highlights the complex interactions between ARGs and nitrogen cycling processes in subtropical estuaries, and will provide a scientific base for couple management strategies of nitrogen and antibiotic pollution.202540934587
7546120.9997Reduction of antibiotic resistance genes under different conditions during composting process of aerobic combined with anaerobic. Single aerobic or anaerobic composting is reportedly as inefficient for removing antibiotic resistance genes (ARGs) from animal manure. This study investigates the effects of ARG removal during aerobic combined with anaerobic composting (ACA) under different conditions. The results showed that a turning frequency of once a day, the proportion of swine manure and corn straw (3:1) and an anaerobic time of 6 days were the best operating conditions for ARG reduction (>95%, especially ermF: 99.78%) during ACA. Moreover, redundancy analysis demonstrated that the bacterial community (especially Truepera, Petrimonas and Ureibacillus) had a stronger effect on ARG removal than environmental factors did (especially temperature, total phosphorus, ammonia nitrogen and pH). Network analysis indicated the important effect of these potential host bacteria on the spread of ARGs through significant co-occurrence between individual ARGs and specific bacteria. These findings offer an effective technology to reduce and block ARGs spread from animal manure.202133493747
8060130.9997Responses of bacterial communities and antibiotic resistance genes to nano-cellulose addition during pig manure composting. Treatment with exogenous additives during composting can help to alleviate the accumulation of antibiotic resistance genes (ARGs) caused by the direct application of pig manure to farmland. In addition, nano-cellulose has an excellent capacity for adsorbing pollutants. Thus, the effects of adding 300, 600, and 900 mg/kg nano-cellulose to compost on the bacterial communities, mobile genetic elements (MGEs), and ARGs were determined in this study. After composting, treatment with nano-cellulose significantly reduced the relative abundance of ARGs, which was lowest in the compost product with 600 mg/kg added nano-cellulose. Nano-cellulose inhibited the rebound in ARGs from the cooling period to the maturity period, and weakened the selective pressure of heavy metals on microorganisms by passivating bio-Cu. The results also showed that MGEs explained most of the changes in the abundances of ARGs, and MGEs had direct effects on ARGs. The addition of 600 mg/kg nano-cellulose reduced the abundances of bacterial genera associated with ermQ, tetG, and other genes, and the number of links (16) between ARGs and MGEs was lowest in the treatment with 600 mg/kg added nano-cellulose. Therefore, adding 600 mg/kg nano-cellulose reduced the abundances of ARGs by affecting host bacteria and MGEs. The results obtained in this study demonstrate the positive effect of nano-cellulose on ARG pollution in poultry manure, where adding 600 mg/kg nano-cellulose was most effective at reducing the abundances of ARGs.202134649327
6912140.9997Regulation of antibiotic resistance gene rebound by degrees of microecological niche occupation by microbiota carried in additives during the later phases of swine manure composting. The occupation of microecological niches (MNs) by bacteria carrying lower antibiotic resistance genes (ARGs) has been demonstrated an effective strategy for reducing ARGs in compost, thereby mitigating the associated land use risks. In this study, humus soil (HS), matured compost (MC), and their respective isolated microbial agents (HSM and MCM), which exhibit varying abundances of ARGs, were introduced as additives after the thermophilic phase to investigate their influence on ARG removal and the mechanisms underlying effective MN occupation. The addition of HS resulted in the most favorable outcomes, including the highest carbon degradation, minimized nitrogen loss, and an 83.16 % reduction in ARG abundance during the later composting stages. In comparison, ARG rebound levels were 61.77 %-285.33 % across other treatments and 729.23 % in the control. Distinct dominant bacterial genera and potential ARG-host bacterial communities were observed, which varied with different additives and contributed to MN occupation dynamics. The addition of the HS additive intensified competition among non-host bacteria, and diversified the interactions both between genes and between bacteria. These changes suppressed horizontal gene transfer (HGT) mediated by mobile genetic elements (MGEs) and altered the abundance and composition of both dominant and non-dominant potential host species. Furthermore, it shifted the relative importance of key physicochemical parameters, collectively enhancing ARG removal during composting. These findings elucidate the mechanisms by which MN adjustments contribute to ARG reduction, providing actionable insights for designing composting strategies that mitigate environmental ARG dissemination risks more effectively.202540154224
7551150.9997Microbial community evolution and fate of antibiotic resistance genes during sludge treatment in two full-scale anaerobic digestion plants with thermal hydrolysis pretreatment. Anaerobic digestion (AD) with thermal hydrolysis pretreatment is widely used as an efficient sludge treatment nowadays. However, the evolution of microbial community (especially for the archaea community), the fate of antibiotic resistance genes (ARGs), and their associations during such process in full-scale sludge treatment plants are rarely reported. Therefore, these scientific questions were explored at two full-scale sludge treatment plants through high-throughput sequencing and quantitative PCR. Results showed that Methanobacterium and Methanosphaera were the dominant archaea in thermal hydrolyzed sludge. The predominant bacteria in the sludge first shifted from nutrients removal functional bacteria to spore-forming bacteria after thermal hydrolysis, and then shifted to fermentative bacteria after AD. The full-scale plants could select ermB, ermF, mefA/E, qnrS and tetM. Though the bacteria and archaea biomass and community largely influenced the fate of ARGs, multiple linear regression analysis showed that the total ARGs were mainly affected by mobile genetic elements (MGEs).201931158777
7547160.9997Mechanism concerning the occurrence and removal of antibiotic resistance genes in composting product with ozone post-treatment. The soil application of composting product will probably cause the spread of antibiotic resistance genes (ARGs) to environment, thereby it is crucial to remove ARGs in composting product. Ozone was adopted for the first time as a post-treatment method to remove the ARGs in composting product in this study. Ozone treatment significantly removed the total ARGs and mobile genetic elements (MGEs) once ozonation process finished. After 10-day storage stage, although the amount of total intracellular ARGs and MGEs increased, the total extracellular ARGs and MGEs decreased in the ozone-treated compost product. Correlation analysis revealed that the reduction in intracellular 16S rRNA contributed to intracellular tetQ and tetW removal, while the variations of other ARGs after ozonation related to MGEs abundance. Network analysis suggested that the reduction of potential host bacteria, as well as the decline in NH(4)(+)-N and TOC after the ozonation, contributed to the intracellular ARGs removal.202133257169
7040170.9997The maturity period is the main stage of antibiotic resistance genes reduction in aerobic composting process of swine manure in sub-scale farms. This study was focused on the changes of antibiotic resistance genes (ARGs) and their potential host bacteria during the swine manure composting on sub-scale farms. Eight target ARGs increased 427% on average, with a trend of increase at early stage and decrease at later stage, and the main reduction stage appeared in maturity stage. The abundance of ARGs was mainly affected by the community succession of potential host bacteria. Composting could reduce the abundance of potential host bacteria of ARGs as well as pathogens such as Pseudomonas, and reduce the environmental risks of swine manure. N/C and S levels had a positive effect on the potential host of most ARGs. Prolonging the maturity period would inhibit the growth of potential host bacteria of ARGs during composting, therefore inhibiting the transmission of ARGs.202132971337
6914180.9997Responses of antibiotic and heavy metal resistance genes to bamboo charcoal and bamboo vinegar during aerobic composting. The application of compost in agriculture has led to the accumulation of antibiotic resistance genes (ARGs) and heavy metal resistance genes (MRGs) in the soil environment. In this study, the response of ARGs and MRGs to bamboo charcoal (BC) and bamboo vinegar (BV) during aerobic composting was investigated. Results showed that BC + BV treatment reduced the abundances of ARGs and mobile genetic elements (MGEs) during the thermophilic period, as well as achieved the lowest rebound during the cooling period. BC + BV promoted the growth of Firmicutes, thereby facilitating the thermophilic period of composting. The rebound of ARGs and MGEs can be explained by increasing the abundance of Actinobacteria and Proteobacteria at the end of composting. Composting reduced the abundances of MRGs comprising pcoA, tcrB, and cueO, whereas cusA and copA indicated the selective pressure imposed by heavy metals on bacteria. The fate of ARGs was mainly driven by MGEs, and heavy metals explained most of the variation in MRGs. Interestingly, nitrogen conversion also had an important effect on ARG and MRG profiles. Our current findings suggest that the addition of BC + BV during compost preparation is an effective method in controlling the mobility of ARGs and MRGs, thereby reducing the environmental problems.201931252107
8578190.9997Impact of earthworms on suppressing dissemination of antibiotic resistance genes during vermicomposting treatment of excess sludge. Earthworms play a crucial role in suppressing the dissemination of antibiotic resistance genes (ARGs) during vermicomposting. However, there is still a lack of how earthworms influence the spread of ARGs. To address this gap, a microcosm experiment was conducted, incorporating earthworms and utilizing metagenomics and quantitative PCR to assess the impact of earthworms on microbial interactions and the removal of plasmid-induced ARGs. The findings revealed that vermicomposting led to a reduction in the relative abundance of ARGs by altering microbial communities and interactions. Significantly, vermicomposting demonstrated an impressive capability, reducing 92% of ARGs donor bacteria and impeding the transmission of 94% of the RP4 plasmid. Furthermore, through structural equation model analysis, it was determined that mobile genetic elements and environmental variables were the primary influencers of ARG reduction. Overall, this study offers a fresh perspective on the effects of vermicomposting and its potential to mitigate the spread of ARGs.202438885722