Interaction of sulfate-reducing bacteria and methanogenic archaea in urban sewers, leads to increased risk of proliferation of antibiotic resistance genes. - Related Documents




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755801.0000Interaction of sulfate-reducing bacteria and methanogenic archaea in urban sewers, leads to increased risk of proliferation of antibiotic resistance genes. Sewers are considered a potential reservoir of antibiotic resistance. However, the generation of antibiotic resistance genes (ARGs) in microbial communities in pipeline biofilms under antibiotic stress remains unexplored. In this study, the biodegradation efficiency of tetracycline (TCY) and sulfamethoxazole (SMX) was evaluated in a pilot reactor of the sewers. The results showed that under TCY and SMX stress, the degradation efficiency of sewage water was inhibited. The most abundant ARGs detected in the biofilm samples were TCY-related genes (e.g., tetW/N/W, tetC, and tetM), accounting for 34.1%. The microbial community composition varied, and the correlation analysis showed that antibiotic stress had a certain impact on the biological metabolic activity and function of the urban sewers. The community structure and diversity of biofilms enabled the evaluation of the bioconversion of antibiotics. Notably, Anaerocella and Paludibacter directly influenced the methanogenesis and sulfate reduction processes, playing a key role in the interaction between sulfate-reducing bacteria and methanogenic archaea. These microorganisms facilitated the proliferation of ARGs (tet and sul) in the biofilms through horizontal gene transfer. This study provides insight into the front-end control of ARGs, further improving sewage treatment plant processes and reducing the environmental and health risks caused by antibiotic abuse.202539894155
756010.9998The effect of bacterial functional characteristics on the spread of antibiotic resistance genes in Expanded Granular Sludge Bed reactor treating the antibiotic wastewater. To explore the fate and spreading mechanism of antibiotics resistance genes (ARGs) in antibiotics wastewater system, a laboratory-scale (1.47 L) Expanded Granular Sludge Bed (EGSB) bioreactor was implemented. The operating parameters temperature (T) and hydraulic retention time (HRT) were mainly considered. This result showed the removal of ARGs and COD was asynchronous, and the recovery speed of ARGs removal was slower than that COD removal. The decreasing T was attributed to the high growth rate of ARGs host bacteria, while the shortened HRT could promote the horizontal and vertical gene transfer of ARGs in the sludge. The analysis result of potential bacterial host showed more than half of the potential host bacteria carried 2 or more ARGs and suggested an indirect mechanism of co-selection of multiple ARGs. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to investigate the functional characteristics of bacterial community. This result showed the bacterial functional genes contributed 40.41% to the abundance change of ARGs in the sludge, which was higher that of bacterial community. And the function genes of "aromatic hydrocarbon degradation", "Replication, recombination and repair proteins" and "Flagellar assembly" were mainly correlated with the transfer of ARGs in the sludge. This study further revealed the mechanism of ARGs spread in the EGSB system, which would provide new ideas for the development of ARGs reduction technology.202134488144
755120.9998Microbial 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
755230.9998Effect of temperature on removal of antibiotic resistance genes by anaerobic digestion of activated sludge revealed by metagenomic approach. As antibiotic resistance continues to spread globally, there is growing interest in the potential to limit the spread of antibiotic resistance genes (ARGs) from wastewater sources. In particular, operational conditions during sludge digestion may serve to discourage selection of resistant bacteria, reduce horizontal transfer of ARGs, and aid in hydrolysis of DNA. This study applied metagenomic analysis to examine the removal efficiency of ARGs through thermophilic and mesophilic anaerobic digestion using bench-scale reactors. Although the relative abundance of various ARGs shifted from influent to effluent sludge, there was no measureable change in the abundance of total ARGs or their diversity in either the thermophilic or mesophilic treatment. Among the 35 major ARG subtypes detected in feed sludge, substantial reductions (removal efficiency >90%) of 8 and 13 ARGs were achieved by thermophilic and mesophilic digestion, respectively. However, resistance genes of aadA, macB, and sul1 were enriched during the thermophilic anaerobic digestion, while resistance genes of erythromycin esterase type I, sul1, and tetM were enriched during the mesophilic anaerobic digestion. Efflux pump remained to be the major antibiotic resistance mechanism in sludge samples, but the portion of ARGs encoding resistance via target modification increased in the anaerobically digested sludge relative to the feed. Metagenomic analysis provided insight into the potential for anaerobic digestion to mitigate a broad array of ARGs.201525994259
756140.9998Deciphering antibiotic resistome variations during nitrogen removal process transition under mixed antibiotics stress: Assembly process and driving factors. Antibiotic resistome, which encompasses all types of antibiotic resistance genes (ARGs) in a given environment, has received increasing attention in research on different wastewater treatment processes. However, the variation in antibiotic resistome during the transition from the full nitrification-denitrification to the shortcut nitrification-denitrification process remains unclear. In this study, a total of 269 targeted gene subtypes were identified, along with 108 genes were consistently present in all samples. The introduction of mixed antibioticsrapidly increased the abundance of corresponding and non-corresponding ARGs, as well as that of mobile genetic elements.The variations in of the antibiotic resistome were primarily driven by dissolved oxygen and nitrite accumulation rate. Moreover, 34 bacterial genera were identified as potential ARG hosts, with most denitrifiers considered as potential antibiotic-resistant bacteria, including Branchymonas, Rhodobacter, and Thauera. This study provides a method for controlling antibiotic resistance by regulating the changes in environmental variables and bacterial communities.202339492537
703050.9998Metagenomic profiling of antibiotic resistance genes/bacteria removal in urban water: Algal-bacterial consortium treatment system. Antibiotic resistance genes (ARGs) have exhibited significant ecological concerns, especially in the urban water that are closely associated with human health. In this study, with presence of exogenous Chlorella vulgaris-Bacillus licheniformis consortium, most of the typical ARGs and MGEs were removed. Furthermore, the relative abundance of potential ARGs hosts has generally decreased by 1-4 orders of magnitude, revealing the role of algal-bacterial consortium in cutting the spread of ARGs in urban water. While some of ARGs such as macB increased, which may be due to the negative impact of algicidal bacteria and algal viruses in urban water on exogenous C. vulgaris and the suppression of exogenous B. licheniformis by indigenous microorganisms. A new algal-bacterial interaction might form between C. vulgaris and indigenous microorganisms. The interplay between C. vulgaris and bacteria has a significant impact on the fate of ARGs removal in urban water.202438801952
858960.9998Impacts 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
808670.9998Biofilm enhanced the mitigations of antibiotics and resistome in sulfadiazine and trimethoprim co-contaminated soils. Reducing antibiotic levels in soil ecosystems is vital to curb the dissemination of antimicrobial resistance genes (ARGs) and mitigate global health threats. However, gaps persist in understanding how antibiotic resistome can be suppressed during antibiotic degradation. Herein, we investigate the efficacy of a biochar biofilm incorporating antibiotics-degrading bacterial strain (Arthrobacter sp. D2) to mitigate antibiotic resistome in non-manured and manure-amended soils with sulfadiazine (SDZ) and trimethoprim (TMP) contamination. Results show that biofilm enhanced SDZ degradation by 83.0% within three days and increased TMP attenuation by 55.4% over 60 days in non-manured soils. In the non-manured black soil, the relative abundance of ARGs increased initially after biofilm inoculation. However, by day 30, it decreased by 20.5% compared to the controls. Moreover, after 7 days, biofilm reduced TMP by 38.5% in manured soils and decreased the total ARG abundance by 19.0%. Thus, while SDZ degradation did not increase sulfonamide resistance genes, TMP dissipation led to a proliferation of insertion sequences and related TMP resistance genes. This study underscores the importance of antibiotic degradation in reducing related ARGs while cautioning against the potential proliferation and various ARGs transfer by resistant microorganisms.202439255667
808280.9998Deciphering the toxic effects of antibiotics on denitrification: Process performance, microbial community and antibiotic resistance genes. The extensive application of antibiotics, and the occurrence and spread of antibiotic resistance genes (ARGs) shade health risks to human and animal. The long-term effects of sulfamethoxazole (SMX) and tetracycline (TC) on denitrification process were evaluated in this study, with the focus on nitrogen removal performance, microbial community and ARGs. Results showed that low-concentration SMX and TC (<0.2 mg L(-1)) initially caused a deterioration in nitrogen removal performance, while higher concentrations (0.4-20 mg L(-1)) of both antibiotics had no further inhibitory influences. The abundances of ARGs in both systems generally increased during the whole period, and most of them had significant correlations with intI1, especially efflux-pump genes. Castellaniella, which was the dominant genus under antibiotic pressure, might be potential resistant bacteria. These findings provide an insight into the toxic effects of different antibiotics on denitrification process, and guides future efforts to control antibiotics pollution in ecosystems.202032250829
793190.9998The stress response of tetracycline resistance genes and bacterial communities under the existence of microplastics in typical leachate biological treatment system. Landfill leachate is an important source of microplastics (MPs) and antibiotic-resistance genes (ARGs). Here, in the presence of polystyrene MPs (PS-MPs) and polyethylene MPs (PE-MPs), the nitrogen and phosphorus removal effect and sludge structure performance were affected in an anaerobic-anoxic-aerobic system, a typical biological leachate treatment process. The abundance of tetracycline-resistance genes (tet genes) in biofilms on the two types of MP was significantly higher than that in the leachate and sludge, and the load on PE-MPs was higher than that on PS-MPs because of the porous structure of PE-MPs. Aging of the MPs increased their surface roughness and abundance of oxygen-containing functional groups and shaped the profile of ARGs in the MP biofilms. The biofilm biomass and growth rate on the two types of MP increased with the incubation time in the first 30 days, and was affected by environmental factors. Structural equation models and co-occurrence network analysis demonstrated that the MPs indirectly affected the spectrum of ARGs by affecting biofilm formation, and, to a lesser extent, had a direct impact on the selective enrichment of ARGs. We discuss the mechanisms of the relationships between MPs and ARGs in the leachate treatment system, which will have guiding significance for future research. Our data on the colonization of microorganisms and tet genes in MPs biofilms provide new evidence concerning the accumulation and transmission of these ARGs, and are important for understanding the mechanisms of MPs in spreading pollution.202439018858
8588100.9998Does lipid stress affect performance, fate of antibiotic resistance genes and microbial dynamics during anaerobic digestion of food waste? The dissemination of antibiotic resistance genes (ARGs) in food waste (FW) disposal can pose severe threats to public health. Lipid is a primary composition in FW, while whether lipid stress can affect ARGs dynamics during anaerobic digestion (AD) process of FW is uncertain. This study focused on the impacts of lipid stress on methane production, fate of ARGs and its microbial mechanisms during AD of FW. Results showed that high lipid content increased methane yield but prolonged hydrolysis and lag time of methane production compared to AD of FW without oil. Moreover, variations of ARGs were more susceptible to lipid stress. Lipid stress could facilitate the reduction of total ARGs abundances compared to the group without oil, particularly restraining the proliferation of sul1, aadA1 and mefA in AD systems (P < 0.05). Mantel test suggested that integrons (intl1 and intl2) were significantly correlated with all detected ARGs (r: 0.33, P < 0.05), indicating that horizontal gene transfer mediated by integrons could be the driving force on ARGs dissemination. Network analysis suggested that Firmicutes, Bacteroidetes, Synergistetes and Proteobacteria were the main potential hosts of ARGs. In addition, under the lipid stress, the reduction of host bacteria was responsible for the elimination of several specific ARGs, thereby affecting ARGs profiles. These findings firstly deciphered ARGs dynamics and their driving factors responding to lipid stress during anaerobic biological treatment of FW.202133250254
7559110.9998Fate of antibiotic resistance genes and resistant bacteria under various operating temperatures of sludge anaerobic digestion. This study investigates the impact of varying temperatures on reducing antibiotic resistance genes (ARGs) during anaerobic digestion (AD) of mixed raw sludge in wastewater treatment plants. Employing three different operating temperatures, i.e., 37, 55, and 65 °C, the research aims to identify how these conditions affect the diminution of resistant genes. The results, based on quantitative PCR analysis and metagenomic sequencing, show that higher temperatures significantly enhance the reduction of ARGs, with the most substantial decreases observed at 65 °C. This temperature-dependent reduction correlates with changes in the microbial community structure, where specific bacterial genera like Alicycliphilus, Macellibacteroides, Dokdonella, Ahniella, Thauera, and Zoogloea associated with ARGs exhibit decreased abundance at elevated temperatures. The study infers that AD at higher temperatures could be a more effective strategy in mitigating the spread of antibiotic resistance in the environment, suggesting a pivotal role of operational temperature in optimizing wastewater treatment processes for ARGs attenuation. The findings highlight the need for further research to refine AD protocols, aiming to minimize the environmental impact of antibiotic resistance dissemination.202540662898
7032120.9998Free Radicals on Aging Microplastics Regulated the Prevalence of Antibiotic Resistance Genes in the Aquatic Environment: New Insight into the Effect of Microplastics on the Spreading of Biofilm Resistomes. The spread of antibiotic resistance genes (ARGs) by microplastics has received a great concern in coexisting "hotspots". Despite most microplastics suffering from natural aging, little is known about the effect of aging microplastics (A-MPs) on ARGs dissemination. Here, we demonstrated significant suppression of A-MPs on ARGs dissemination in natural rivers. Although ARGs and mobile genetic elements (MGEs) were effectively enriched on A-MPs, the relative abundance of ARGs and MGEs on A-MPs as well as in receiving water decreased by approximately 21.4% to 42.3% during a period of 30 days of dissemination. Further investigation revealed that (•)OH was consistently generated on A-MPs with a maximum value of 0.2 μmol/g. Importantly, scavenging of (•)OH significantly increased the relative abundance of ARGs and MGEs both on A-MPs and in receiving water 1.4-29.1 times, indicating the vital role of (•)OH in suppressing ARGs dissemination. Microbial analysis revealed that (•)OH inhibited the potential antibiotic-resistant bacteria in surface biofilms, such as Pseudomonas and Acinetobacter (with a decrease of 68.8% and 89.3%). These results demonstrated that (•)OH was extensively produced on A-MPs, which greatly reduced both the vertical and horizontal gene transfer of ARGs. This study provided new insights into the dissemination of ARGs through microplastics in natural systems.202540359213
7022130.9998Fate of antibiotics, antibiotic-resistant bacteria, and cell-free antibiotic-resistant genes in full-scale membrane bioreactor wastewater treatment plants. The removal of antibiotics, antibiotic-resistant bacteria (ARB), and cell-free antibiotic-resistant genes (ARGs) and the microbial community of ARB were investigated in detail to understand their fate and provide valuable information on the feasibility of full-scale membrane bioreactor (MBR). The potential risks of cell-free ARGs to the receiving environment were discovered. High influent antibiotic concentration could inhibit the microbial activity of MBR sludge, whereas good antibiotic removal could be maintained because of relatively long solid retention time and high biomass retention. Approximately 61.8%-77.5% of the total antibiotics were degraded, and 22.5%-38.2% of the total antibiotics were adsorbed by MBR sludge on average. The individual antibiotic removal presented intense discrepancy because of the chemical construction and distribution coefficient of antibiotics. Aeromonas exhibited specific antibiotic resistance to ampicillin and erythromycin, Escherichia became the predominant genera in kanamycin-ARB and tetracycline-ARB, and Klebsiella and Bacteroides were the particular genera that exhibited distinct antibiotic resistance to ciprofloxacin. A significant correlation was found between cell-free ARG abundance and ARB content, and relatively high effluent cell-free ARG abundance facilitated the proliferation and transmission of ARB. The impacts of the receiving environment to eliminate the ecological risks and severe threats to human health should be investigated because of the low decay ratio and long-term persistence of cell-free ARGs.202031986335
7563140.9998Polystyrene microplastics alleviate the effects of sulfamethazine on soil microbial communities at different CO(2) concentrations. Microplastics were reported to adsorb antibiotics and may modify their effects on soil systems. But there has been little research investigating how microplastics may affect the toxicities of antibiotics to microbes under future climate conditions. Here, we used a free-air CO(2) enrichment system to investigate the responses of soil microbes to sulfamethazine (SMZ, 1 mg kg(-1)) in the presence of polystyrene microplastics (PS, 5 mg kg(-1)) at different CO(2) concentrations (ambient at 380 ppm and elevated at 580 ppm). SMZ alone decreased bacterial diversity, negatively affected the bacterial structure and inter-relationships, and enriched the sulfonamide-resistance genes (sul1 and sul2) and class 1 integron (intl1). PS, at both CO(2) conditions, showed little effect on soil bacteria but markedly alleviated SMZ's adverse effects on bacterial diversity, composition and structure, and inhibited sul1 transmission by decreasing the intl1 abundance. Elevated CO(2) had limited modification in SMZ's disadvantages to microbial communities but markedly decreased the sul1 and sul2 abundance. Results indicated that increasing CO(2) concentration or the presence of PS affected the responses of soil microbes to SMZ, providing new insights into the risk prediction of antibiotics under future climate conditions.202133592488
7550150.9998Evaluating the effects of activated carbon on methane generation and the fate of antibiotic resistant genes and class I integrons during anaerobic digestion of solid organic wastes. The effects of activated carbon (AC) on methane production and the fate of antibiotic resistance genes (ARGs) were evaluated through comparing the anaerobic digestion performance and transformation of ARGs among anaerobic mono-digestion of food waste, co-digestion of food waste and chicken manure, and co-digestion of food waste and waste activated sludge. Results showed that adding AC in anaerobic digesters improved methane yield by at least double through the enrichment of bacteria and archaea. Conventional digestion process showed ability in removing certain types of ARGs, such as tetA, tetX, sul1, sul2, cmlA, floR, and intl1. Supplementing AC in anaerobic digester enhanced the removal of most of the ARGs in mono-digestion of food waste. The effects tended to be minimal in co-digestion of co-substrates such as chicken manure and waste activated sludge, both of which contain a certain amount of antibiotics.201829096147
8083160.9998Alteration of the migration trajectory of antibiotic resistance genes by microplastics in a leachate activated sludge system. The environmental behavior of emerging contaminants of microplastics (MPs), antibiotics and antibiotic resistance genes (ARGs) in the leachate activated sludge system has been monitored and analyzed comprehensively. The results suggested that MPs could effectively alter the migration trajectory of tetracycline resistance genes (tet genes) in the leachate activated sludge system under intermittent and continuous influent conditions. After adding MPs, the total average abundance of tet genes in leachate increased from 0.74 ± 0.07 to 0.78 ± 0.07 (log(10)tet genes/log(10) 16S rRNA) and that in sludge increased from 0.65 ± 0.08 to 0.70 ± 0.06 (log(10)tet genes/log(10) 16S rRNA). Except for tetA, the abundance of tetB, tetO, tetM and tetQ on MPs increased with increasing TC concentration under both aerobic and anaerobic conditions. MPs not only significantly affect the abundance level and migration trajectory of ARGs in the leachate activated sludge system, but also remarkably improve the level of heavy metals in the ambient environment, indirectly promoting the selective effect of antibiotic-resistant bacteria (ARB) and promoting the development of antibiotic resistance (AR). In addition, MPs changed their physicochemical properties and released hazardous substances with aging to force tet genes to migrate from the leachate activated sludge system to the MPs, making AR more difficult to eliminate and persisted in wastewater treatment plants. Meanwhile, microorganisms played a driving role, making MPs serve as a niche for ARGs and ARB colonization. The co-occurrence network analysis indicated the specific distribution pattern of tet genes and microorganisms in different media, and the potential host was speculated. This study improves the understanding of the environmental behavior of emerging contaminants in leachate activated sludge system and lays a theoretical for protecting the ecological environment.202337321316
7507170.9998Impact of different organic matters on the occurrence of antibiotic resistance genes in activated sludge. The occurrence of antibiotic resistance genes (ARGs) in various environments has drawn worldwide attention due to their potential risks. Previous studies have reported that a variety of substances can enhance the occurrence and dissemination of ARGs. However, few studies have compared the response of ARGs under the stress of different organic matters in biological wastewater treatment systems. In this study, seven organic pollutants were added into wastewater treatment bioreactors to investigate their impacts on the ARG occurrence in activated sludge. Based on high-throughput sequencing, it was found that the microbial communities and ARG patterns were significantly changed in the activated sludge exposed to these organic pollutants. Compared with the non-antibiotic refractory organic matters, antibiotics not only increased the abundance of ARGs but also significantly changed the ARG compositions. The increase of Gram-negative bacteria (e.g., Archangium, Prosthecobacter and Dokdonella) carrying ARGs could be the main cause of ARG proliferation. In addition, significant co-occurrence relationships between ARGs and mobile genetic elements were also observed in the sludge samples, which may also affect the ARG diversity and abundance during the organic matter treatment in the bioreactors. Overall, these findings provide new information for better understanding the ARG occurrence and dissemination caused by organic pollutants in wastewater treatment systems.202336522059
8084180.9997Metagenomic insights into effects of carbon/nitrogen ratio on microbial community and antibiotic resistance in moving bed biofilm reactor. This study investigated the effects of carbon/nitrogen (C/N) ratio on microbial community in moving bed biofilm reactor (MBBR) using metagenomic analysis, and the dynamic changes of relevant antibiotic resistance genes (ARGs) were also analyzed. The results showed that under low C/N ratio, MBBR exhibited average removal rates of 98.41 % for ammonia nitrogen and 75.79 % for total nitrogen. Metagenomic analysis showed low C/N ratio altered the structure of biofilm and water microbiota, resulting in the detachment of bacteria such as Actinobacteria from biofilm into water. Furthermore, sulfamethazine (SMZ)-resistant bacteria and related ARGs were released into water under low C/N ratio, which lead to the increase of SMZ resistance rate to 90%. Moreover, most dominant genera are potential hosts for both nitrogen cycle related genes and ARGs. Specifically, Nitrosomonas that carried gene sul2 might be released from biofilm into water. These findings implied the risks of antibiotic resistance dissemination in MBBR under low C/N ratio.202438901747
7615190.9997Biofilm processes in treating mariculture wastewater may be a reservoir of antibiotic resistance genes. Antibiotics are heavily used in Chinese mariculture, but only a small portion of the added antibiotics are absorbed by living creatures. Biofilm processes are universally used in mariculture wastewater treatment. In this study, removal of antibiotics (norfloxacin, rifampicin, and oxytetracycline) from wastewater by moving bed biofilm reactors (MBBRs) and the influence of antibiotics on reactor biofilm were investigated. The results demonstrated that there was no significant effect of sub-μg/L-sub-mg/L concentrations of antibiotics on TOC removal. Moreover, the relative abundance of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARB) in MBBR biofilm increased because of selective pressure of antibiotics. In addition, antibiotics decreased the diversity of the biofilm bacterial community and altered bacterial community structure. These findings provide an empirical basis for the development of appropriate practices for mariculture, and suggest that disinfection and advanced oxidation should be applied to eliminate antibiotics, ARGs, and ARB from mariculture wastewater.201728285703