# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 7597 | 0 | 1.0000 | Metagenomic analysis reveals the effects of long-term antibiotic pressure on sludge anaerobic digestion and antimicrobial resistance risk. Continuous stirred-tank digesters with tetracyclines and sulfonamides were operated to investigate the impacts of antibiotic pressure on sludge anaerobic digestion. The versatile methanogen Methanosarcinales and strictly hydrogenotrophic methanogen Methanobacteriales increased and decreased by 21.1% and 10.9% under antibiotic pressure, respectively. KEGG analysis revealed that hydrogenotrophic and acetoclastic methanogenesis pathways were all affected. The decrease in abundance of function genes involved in lipid metabolism, carbohydrate metabolism, and fatty acid degradation, would lead to a reduction in methane production by 25%. Network analysis indicated positive associations among tetracycline residuals, abundance of resistance genes (ARGs), and specific member of potential hosts. Over 1000 ARG subtypes were widely detected in sludge, including macrolide (28%), tetracycline (24%), fluoroquinolone (20%), and peptide (20%) resistance genes. AD process exposed to long-term antibiotic would increase the diversity and abundance of ARG, enhance the association of ARG with specific microbes, and select bacteria able to perform chemotaxis mechanism. | 2019 | 30861447 |
| 8084 | 1 | 0.9998 | Metagenomic 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. | 2024 | 38901747 |
| 7598 | 2 | 0.9997 | Aspartame affects methane yield and enhances transmission of antibiotic resistance genes during anaerobic digestion of sludge. Aspartame (ASP) is a widely used artificial sweetener, yet recent studies have shown that ASP have potential toxic effect. ASP is also detected in sludge, however, the influence of ASP on the performance of sludge anaerobic digestion and the fate of antibiotic resistance genes (ARGs) have not been thoroughly investigated. Under stress of 0, 0.5, 5 and 50 mg/L ASP, cumulative methane production was 181.7, 167.0, 154.0 and 140.8 mlCH(4)/g VSS, respectively. ASP inhibited the dissolution and conversion of organic matter in sludge. Sequencing data revealed a decline in the abundance of functional microorganisms compared to control, such as hydrolytic-acidifying bacteria and methanogens, potentially attributed to increased intracellular reactive oxygen species and damaged cell membranes caused by ASP addition. Specifically, 50 mg/L ASP reduced the total abundance of methanogens by 59.40 % compared to control. Concurrently, alterations in microbial communities along with an increase in Tn916 and intI1 were observed, increasing the abundance of ARGs. The total abundance of five ARGs peaked at 1.43E+ 12 copies/g at 5 mg/L ASP, representing 139 % of the control. This research contributes valuable insights into the alterations in anaerobic digestion caused by ASP, emphasizing the potential risks in the overall environmental system. | 2025 | 39616849 |
| 8041 | 3 | 0.9997 | Insights into the microalgae-bacteria consortia treating swine wastewater: Symbiotic mechanism and resistance genes analysis. This study investigated the effects of microalgae-bacteria consortia (MBC) (Chlorella pyrenoidosa-activated sludge (AS)) treating swine wastewater with low C/N ratios. After co-culture, the removal rates of NH(4)(+)-N and PO(4)(3-)-P increased by 53.84% and 43.52%. Furthermore, the sulfamethoxazole (SMX) degradation rates in MBC were slightly higher than in the activated sludge process. Interestingly, the absolute abundance of antibiotic resistance genes (ARGs) in effluent from MBC is relatively less than in the AS process. C. pyrenoidosa has a negative zeta potential that allows bacteria to adhere to its surface. The concentrations of carbohydrates and proteins in extracellular polymeric substance (EPS) of MBC dramatically increased compared with the AS process. At the phylum level, Proteobacteria, Bacteroidota, and Cyanobacteria were the main bacteria, while Ascomycota and Basidiomycota were the primary fungi in MBC. Overall, those findings lead to a better understanding of the swine wastewater containing antibiotic treatment by MBC. | 2022 | 35217162 |
| 7564 | 4 | 0.9997 | Formation, characteristics and microbial community of aerobic granular sludge in the presence of sulfadiazine at environmentally relevant concentrations. The growing occurrence of antibiotics in water environment is causing increasing concern. To investigate the impact of frequently detected sulfadiazine on the formation of aerobic granular sludge, four sequencing batch reactors (SBRs) were set up with different environmentally relevant concentrations of sulfadiazine. Results showed that sulfadiazine pressure could lead to larger and more compact sludge particles and cause slight effect on reactor performance. Presence of sulfadiazine apparently increased the extracellular polymeric substances (EPS) secretion of microorganisms. Quantitative polymerase chain reaction (qPCR) showed that the abundances of sulfanilamide resistance genes in sludge increased with addition of sulfadiazine significantly. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predict functional genes, results showed that sulfadiazine led to an increase of specific functional genes. Thereby, it concluded that microorganisms could change the community structure by acclimating of functional bacteria and antibiotic resistance species to adapt to the antibiotic stress. | 2018 | 29197771 |
| 7596 | 5 | 0.9997 | The impact and fate of clarithromycin in anaerobic digestion of waste activated sludge for biogas production. Clarithromycin retained in waste activated sludge (WAS) inevitably enters the anaerobic digestion system. So far, the complex impacts and fate of clarithromycin in continuous operated WAS anaerobic digestion system are still unclear. In this study, two semi-continuous long-term reactors were set up to investigate the effect of clarithromycin on biogas production and antibiotic resistance genes (ARGs) during WAS anaerobic digestion, and a batch test was carried out to explore the potential metabolic mechanism. Experimental results showed that clarithromycin at lower concentrations (i.e., 0.1 and 1.0 mg/L) did not affect biogas production, whereas the decrease in biogas production was observed when the concentration of clarithromycin was further increased to 10 mg/L. Correspondingly, the relative abundance of functional bacteria in WAS anaerobic digestion (i.e., Anaerolineaceae and Microtrichales) was reduced with long-term clarithromycin exposure. The investigation of ARGs suggested that the effect of methylation belonging to the target site modification played a critical role for the anaerobic microorganisms in the expression of antibiotic resistance, and ermF, played dominated ARGs, presented the most remarkable proliferation. In comparison, the role of efflux pump was weakened with a significant decrease of two detected efflux genes. During WAS anaerobic digestion, clarithromycin could be partially degraded into metabolites with lower antimicrobial activity including oleandomycin and 5-O-desosaminyl-6-O-methylerythronolide and other metabolites without antimicrobial activity. | 2021 | 33545126 |
| 7192 | 6 | 0.9997 | Sulfamethoxazole and COD increase abundance of sulfonamide resistance genes and change bacterial community structures within sequencing batch reactors. The abundant microbial community in biological treatment processes in wastewater treatment plants (WWTPs) may potentially enhance the horizontal gene transfer of antibiotic resistance genes with the presence of antibiotics. A lab-scale sequencing batch reactor was designed to investigate response of sulfonamide resistance genes (sulI, sulII) and bacterial communities to various concentrations of sulfamethoxazole (SMX) and chemical oxygen demand (COD) of wastewater. The SMX concentrations (0.001 mg/L, 0.1 mg/L and 10 mg/L) decreased with treatment time and higher SMX level was more difficult to remove. The presence of SMX also significantly reduced the removal efficiency of ammonia nitrogen, affecting the normal function of WWTPs. All three concentrations of SMX raised both sulI and sulII genes with higher concentrations exhibiting greater increases. The abundance of sul genes was positive correlated with treatment time and followed the second-order reaction kinetic model. Interestingly, these two genes have rather similar activity. SulI and sulII gene abundance also performed similar response to COD. Simpson index and Shannon-Weiner index did not show changes in the microbial community diversity. However, the 16S rRNA gene cloning and sequencing results showed the bacterial community structures varied during different stages. The results demonstrated that influent antibiotics into WWTPs may facilitate selection of ARGs and affect the wastewater conventional treatment as well as the bacteria community structures. | 2017 | 28211331 |
| 8071 | 7 | 0.9997 | Impact of ciprofloxacin and copper combined pollution on activated sludge: Abundant-rare taxa and antibiotic resistance genes. This study aimed to explore the impacts of ciprofloxacin (CIP, 0.05-40 mg/L) and copper (3 mg/L) combined pollution on nitrification, microbial community and antibiotic resistance genes (ARGs) in activated sludge system during stress- and post-effect periods. Higher CIP concentration inhibited nitrification and an average of 50% total nitrogen removal occurred under 40 mg/L of CIP pressure. The stress- and post-effects on bacterial diversity and structure were obviously distinct. Abundant genera were more sensitive to combined pollution than rare genera based on full-scale classification and conditionally rare or abundant taxa were keystone taxa in their interactions. Ammonia oxidation genes were inhibited under high CIP level, but some aerobic denitrifying bacteria (Thauera, Comamonas and Azoarcus) and key genes increased. 96 ARG subtypes were detected with complex positive relationships and their potential hosts (abundant-rare-functional genera) changed in two periods. This study highlights the different stress- and post-effects of combined pollution on activated sludge. | 2022 | 35217161 |
| 8588 | 8 | 0.9997 | Does 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. | 2021 | 33250254 |
| 7550 | 9 | 0.9997 | Evaluating 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. | 2018 | 29096147 |
| 8086 | 10 | 0.9997 | Biofilm 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. | 2024 | 39255667 |
| 7582 | 11 | 0.9997 | Anaerobic fermentation for hydrogen production and tetracycline degradation: Biodegradation mechanism and microbial community succession. The misuse and continues discharge of antibiotics can cause serious pollution, which is urgent to take steps to remit the environment pollution. In this study, anaerobic bacteria isolated from the aeration tank of a local sewage treatment plant were employed to investigate hydrogen production and tetracycline (TC) degradation during anaerobic fermentation. Results indicate that low concentrations of TC enhanced hydrogen production, increasing from 366 mL to a maximum of 480 mL. This increase is attributed to stimulated hydrolysis and acidogenesis, coupled with significant inhibition of homoacetogenesis. Furthermore, the removal of TC, facilitated by adsorption and biodegradation, exceeded 90 %. During the fermentation process, twenty-one by-products were identified, leading to the proposal of four potential degradation pathways. Analysis of the microbial community revealed shifts in diversity and a decrease in the abundance of hydrogen-producing bacteria, whereas bacteria harboring tetracycline resistance genes became more prevalent. This study provides a possibility to treat tetracycline-contaminated wastewater and to produce clean energy simultaneously by anaerobic fermentation. | 2024 | 39168318 |
| 8093 | 12 | 0.9997 | Acidic conditions enhance the removal of sulfonamide antibiotics and antibiotic resistance determinants in swine manure. Manure pH may vary depending on its inherent composition or additive contents. However, the effect of pH on the fate of antibiotics and antibiotic resistance determinants in manure remains unclear. This work demonstrated that pH adjustment promoted the removal of different sulfonamide antibiotics (SAs) within swine manure under incubation conditions, which increased from 26-60.8% to 75.0-86.0% by adjusting the initial pH from neutral (7.4) to acidic (5.4-4.8). Acidification was also demonstrated to inhibit the accumulation of antibiotic resistance genes in manure during incubation. Acidified manure contained both lower absolute and relative abundances of sul1 and sul2 than those at a neutral pH like 7.4. Further investigation indicated that acidification promoted the reduction of sul genes in manure by restricting sulfonamide-resistant bacteria (SRB) proliferation and inhibiting IntI1 accumulation. Furthermore, pH adjustment significantly influenced the composition of the manure bacterial community after incubation, which increased Firmicutes and decreased Proteobacteria. Close relationships were observed between pH-induced enrichment of the Firmicutes bacterial phylum, enhanced SAs degradation, and the fates of antibiotic resistance determinants. Overall, lowering the pH of manure promotes the degradation of SAs, decreases sul genes and SRB, and inhibits horizontal sul gene transfer, which could be a simple yet highly-effective manure management option to reduce antibiotic resistance. | 2020 | 32302890 |
| 7964 | 13 | 0.9997 | Fate of sulfonamide resistance genes during sludge anaerobic fermentation: Roles of sludge components and fermentation pHs. This study assessed potential effects of two neglected factors (sludge components and pH values) on the fate of sulfonamide (sul) resistance genes during sludge anaerobic fermentation. It was found that sludge with different contents of protein, carbohydrate and humic acid caused no significant changes in the abundances of sul genes. Nevertheless, sul genes were sensitive to pHs (4-10), and the maximum attenuations (0.8-1.1 log unit) were obtained at pH 10. Mechanism exploration indicated that pHs drove the community evolution of sulfonamide resistant bacteria (SRB), most of which were affiliated to the pH-enriched phyla but not the pH-enriched dominant genera. In addition, the relative abundances of SRB were decreased under both acidic and alkaline conditions. Furthermore, the abundances of intI 1 as well as the sul-carrying abilities of plasmid and extracellular DNA were all reduced at test pHs, indicating that the potential of horizontal gene transfer among bacteria was restricted. | 2019 | 31226672 |
| 7549 | 14 | 0.9997 | Fate of antibiotic resistance genes during sludge anaerobic fermentation: Roles of different sludge pretreatment. Excess sludge, the primary by-product of wastewater treatment plants, is the source and sink of antibiotic resistance genes (ARGs). Sludge pretreatments are an indispensable pathway to improve the resource recovery and harmfulness for anaerobic digestion sludge. However, fewer studies have compared the effects of different pretreatment technologies on the distribution of ARGs during anaerobic sludge digestion. Here, this study established seven anaerobic digesters, and four typical ARGs and one integrase gene of class 1 integron (intI1) regarded as the representative mobile genetic elements (MGEs) were examined during the whole anaerobic digestion process. It was found anaerobic digestion could effectively remove ARGs with about 70.86% removal rate of total ARGs. Among these pretreatments, the reduce efficiency of ARGs was the highest in 50 °C pretreatment, followed by oxidant, and the last was acid-alkaline. The microbial community analysis demonstrated the microbial community structure, including ARGs hosts and antibiotic resistant bacteria, was significantly changed and influenced by high temperature pretreatment. In addition, high temperature and K(2)S(2)O(8) observably decrease the level of ROS production. Macro transcriptome analysis indicated that sludge pretreatment, except for 50 °C pretreatment, up-regulated the genes relevant to lyases and transferase, but down-regulated the genes responsible for peroxidase, antioxidant enzymes and T4SS gene. This study emphasized and compared the different sludge pretreatments on the fate of ARGs in anaerobic sludge, and highlighted concerns regarding the environmental and health risks to our society. | 2024 | 39393457 |
| 7916 | 15 | 0.9997 | Effects of combined antibiotics on nitrification, bacteria and antibiotic resistance genes in activated sludge: Insights from legacy effect of antibiotics. The effect of combined antibiotics exposure on nitrogen removal, microbial community assembly and proliferation of antibiotics resistance genes (ARGs) is a hotspot in activated sludge system. However, it is unclear that how the historical antibiotic stress affects the subsequent responses of microbes and ARGs to combined antibiotics. In this study, the effects of combined sulfamethoxazole (SMX) and trimethoprim (TMP) pollution on activated sludge under legacy of SMX or TMP stress with different doses (0.005-30 mg/L) were investigated to clarify antibiotic legacy effects. Nitrification activity was inhibited under higher level of combined exposure but a high total nitrogen removal (∼70%) occurred. Based on the full-scale classification, the legacy effect of past antibiotic stress had a marked effect on community composition of conditionally abundant taxa (CAT) and conditionally rare or abundant taxa (CRAT). Rare taxa (RT) were the keystone taxa in the microbial network, and the responses of hub genera were also affected by the legacy of antibiotic stress. Nitrifying bacteria and genes were inhibited by the antibiotics and aerobic denitrifying bacteria (Pseudomonas, Thaurea and Hydrogenophaga) were enriched under legacy of high dose, as were the key denitrifying genes (napA, nirK and norB). Furthermore, the occurrences and co-selection relationship of 94 ARGs were affected by legacy effect. While, some shared hosts (eg., Citrobacter) and hub ARGs (eg., mdtD, mdtE and acrD) were identified. Overall, antibiotic legacy could affect responses of activated sludge to combined antibiotic and the legacy effect was stronger at higher exposure levels. | 2023 | 37225384 |
| 7191 | 16 | 0.9997 | The impact of antimicrobials on the efficiency of methane fermentation of sewage sludge, changes in microbial biodiversity and the spread of antibiotic resistance. The study was designed to simultaneously evaluate the influence of high doses (512-1024 µg/g) the most commonly prescribed antimicrobials on the efficiency of anaerobic digestion of sewage sludge, qualitative and quantitative changes in microbial consortia responsible for the fermentation process, the presence of methanogenic microorganisms, and the fate of antibiotic resistance genes (ARGs). The efficiency of antibiotic degradation during anaerobic treatment was also determined. Metronidazole, amoxicillin and ciprofloxacin exerted the greatest effect on methane fermentation by decreasing its efficiency. Metronidazole, amoxicillin, cefuroxime and sulfamethoxazole were degraded in 100%, whereas ciprofloxacin and nalidixic acid were least susceptible to degradation. The most extensive changes in the structure of digestate microbiota were observed in sewage sludge exposed to metronidazole, where a decrease in the percentage of bacteria of the phylum Bacteroidetes led to an increase in the proportions of bacteria of the phyla Firmicutes and Proteobacteria. The results of the analysis examining changes in the concentration of the functional methanogen gene (mcrA) did not reflect the actual efficiency of methane fermentation. In sewage sludge exposed to antimicrobials, a significant increase was noted in the concentrations of β-lactam, tetracycline and fluoroquinolone ARGs and integrase genes, but selective pressure was not specific to the corresponding ARGs. | 2021 | 33831706 |
| 7584 | 17 | 0.9996 | Responses of microbial community and antibiotic resistance genes to co-existence of chloramphenicol and salinity. In recent years, the risk from environmental pollution caused by chloramphenicol (CAP) has emerged as a serious concern worldwide, especially for the co-selection of antibiotic resistance microorganisms simultaneously exposed to CAP and salts. In this study, the multistage contact oxidation reactor (MCOR) was employed for the first time to treat the CAP wastewater under the co-existence of CAP (10-80 mg/L) and salinity (0-30 g/L NaCl). The CAP removal efficiency reached 91.7% under the co-existence of 30 mg/L CAP and 10 g/L NaCl in the influent, but it fluctuated around 60% with the increase of CAP concentration and salinity. Trichococcus and Lactococcus were the major contributors to the CAP and salinity shock loads. Furthermore, the elevated CAP and salinity selection pressures inhibited the spread of CAP efflux pump genes, including cmlA, tetC, and floR, and significantly affected the composition and abundance of antibiotic resistance genes (ARGs). As the potential hosts of CAP resistance genes, Acinetobacter, Enterococcus, and unclassified_d_Bacteria developed resistance against high osmotic pressure and antibiotic environment using the efflux pump mechanism. The results also revealed that shifting of potential host bacteria significantly contributed to the change in ARGs. Overall, the co-existence of CAP and salinity promoted the enrichment of core genera Trichococcus and Lactococcus; however, they inhibited the proliferation of ARGs. KEY POINTS: • Trichococcus and Lactococcus were the core bacteria related to CAP biodegradation • Co-existence of CAP and salinity inhibited proliferation of cmlA, tetC, and floR • The microorganism resisted the CAP using the efflux pump mechanism. | 2022 | 36205764 |
| 8043 | 18 | 0.9996 | Effect of tetracycline on bio-electrochemically assisted anaerobic methanogenic systems: Process performance, microbial community structure, and functional genes. Bio-electrochemically assisted anaerobic methanogenic systems (An-BES) are highly effective in wastewater treatment for methane production and degradation of toxic compounds. However, information on the treatment of antibiotic-bearing wastewater in An-BES is still very limited. This study therefore investigated the effect of tetracycline (TC) on the performance, microbial community, as well as functional and antibiotic resistance genes of An-BES. TC at 1 and 5 mg/L inhibited methane production by less than 4.8% compared to the TC-free control. At 10 mg/L TC, application of 0.5 and 1.0 V decreased methane production by 14 and 9.6%, respectively. Under the effect of 1-10 mg/L TC, application of 1.0 V resulted in a decrease of current from 42.3 to 2.8 mA. TC was mainly removed by adsorption; its removal extent increased by 19.5 and 32.9% with application of 0.5 and 1.0 V, respectively. At 1.0 V, current output was not recovered with the addition of granular activated carbon, which completely removed TC by adsorption. Metagenomic analysis showed that propionate oxidizing bacteria and methanogens were more abundant in electrode biofilms than in suspended culture. Antibiotic resistance genes (ARGs) were less abundant in biofilms than in suspended culture, regardless of whether voltage was applied or not. Application of 1.0 V resulted in the enrichment of Geobacter in the anode and Methanobacterium in the cathode. TC inhibited exoelectrogens, propionate oxidizing bacteria, and the methylmalonyl CoA pathway, leading to a decrease of current output, COD consumption, and methane production. These findings deepen our understanding of the inhibitory effect of TC in An-BES towards efficient bioenergy recovery from antibiotic-bearing wastewater, as well as the response of functional microorganisms to TC in such systems. | 2022 | 35533856 |
| 8592 | 19 | 0.9996 | Effects of persulfate treatment on the fates of antibiotic resistance genes in waste activated sludge fermentation process and the underlying mechanism. The occurrence of antibiotic resistance genes (ARGs) in waste activated sludge (WAS) fermentation was investigated with persulfate (PS)-based treatment. ARGs affiliated with multidrug (mexP), macrolide (bla(OXA-129)), tetracycline (tetB), sulfonamide (sul1), and vancomycin (vanRG) types were significantly decreased by PS/Fe treatment. Mechanistic investigations revealed that PS/Fe possessed oxidating potential and exhibited devastating effects on WAS fermentation. First, PS/Fe promoted cell structure damage, which facilitated ARGs release from potential hosts. A co-occurrence network analysis indicated that Fe/PS suppressed the proliferation of potential host bacteria. In addition, the PS/Fe treatment induced the decreased abundance of certain functional genes involved in pathways associated with ARGs dissemination. Finally, variation partitioning analysis demonstrated that the microbial community structure exhibited more vital effects on ARGs fates than physicochemical factors (i.e., pH and ORP) and gene expression (i.e., two-component system). This work provided a deeper understanding of the critical factors used to determine ARGs fates during WAS fermentation. | 2022 | 34864181 |