# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 7922 | 0 | 1.0000 | Simultaneous removal and high tolerance of norfloxacin with electricity generation in microbial fuel cell and its antibiotic resistance genes quantification. Norfloxacin (NFLX) is a synthetic antibiotic widely used in the treatment of infectious diseases. In this work, the performance of microbial fuel cells (MFCs) toward NFLX degradation, electricity production and the antibiotics resistances genes (ARGs) generation was investigated. NFLX degradation efficiency and COD removal reached 65.5% and 94.5% respectively. The increase in NFLX concentration (128 mg/L) had no significant influence on NFLX degradation efficiency, COD removal and MFCs voltage output while the electricity was successfully generated. The quantitative polymerase chain reaction (qPCR) indicated low absolute abundances of ARGs (mdtk, mdtm, and pmra) compared with the traditional wastewater treatment plants (WWTPs). Anodic bacteria can survive in the presence of high NFLX concentration and sustain its degradation and electricity production. In terms of NFLX degradation, COD removal, diminished ARGs generation and simultaneous energy production, MFC seems to be a promising technology for antibiotics wastewater treatment with a potential to overcome the ARGs challenge. | 2020 | 32097778 |
| 8044 | 1 | 0.9995 | Effect of tetracycline on nitrogen removal in Moving Bed Biofilm Reactor (MBBR) System. The effect of tetracycline (TC) on nitrogen removal in wastewater treatment plants has become a new problem. This study investigated the effects of TC on nitrogen removal using a Moving Bed Biofilm Reactor system. The results showed that there was no significant effect on nitrogen removal performance when the concentration of TC was 5 mg/L, and that the total nitrogen (TN) removal efficiency could reach 75-77%. However, when the concentration of TC increased to 10 mg/L, the denitrification performance was affected and the TN removal efficiency decreased to 58%. The abundance of denitrifying bacteria such as those in the genus Thauera decreased, and TC-resistant bacteria gradually became dominant. At a TC concentration of 10 mg/L, there were also increases and decreases, respectively, in the abundance of resistance and denitrification functional genes. The inhibitory effect of TC on denitrification was achieved mainly by the inhibition of nitrite-reducing bacteria. | 2022 | 35007308 |
| 7923 | 2 | 0.9995 | Effect of ultrasonic and ozone pretreatment on the fate of enteric indicator bacteria and antibiotic resistance genes, and anaerobic digestion of dairy wastewater. In this study, the effect of ultrasound (US), ozone and US combined with ozone (US/ozone) pretreatments on the fate of enteric indicator bacteria and antibiotic resistance genes (ARGs), and anaerobic digestion (AD) of dairy wastewater was investigated. The pretreatment conditions included US power 200 W, ozone concentration 4.2 mg O(3)/L, and pretreatment time 0-30 min. The results showed that US/ozone pretreatment was effective in the inactivation of enteric indicator bacteria. Total coliforms and enterococci were reduced by 99% and 92% after 30 min US/ozone pretreatment. Pretreatments could not decrease ARGs in absolute concentration, but could decrease ARGs in relative abundance. In the subsequent AD process, methane production increased more than 10% with 20 min ozone or 20 min US/ozone pretreatments. Pretreatment-AD together obviously inhibited the enrichment of ARGs in relative abundance. This study provided a pretreatment way to enhance methane production and to prevent the enrichment of ARGs. | 2021 | 33186838 |
| 7917 | 3 | 0.9995 | Mechanisms of metabolic performance enhancement and ARGs attenuation during nZVI-assisted anaerobic chloramphenicol wastewater treatment. Anaerobic wastewater treatment is a promising technology for refractory pollutant treatment. The nano zero-valent iron (nZVI) assisted anaerobic system could enhance contaminant removal. In this work, we added nZVI into an anaerobic system to investigate the effects on system performances and metabolic mechanism for chloramphenicol (CAP) wastewater treatment. As nZVI concentrations increased from 0 to 1 g/L, the CAP removal efficiency was appreciably improved from 46.5% to 99.2%, while the CH(4) production enhanced more than 20 times. The enhanced CAP removal resulted from the enrichments of dechlorination-related bacteria (Hyphomicrobium) and other functional bacteria (e.g., Zoogloea, Syntrophorhabdus) associated with refractory contaminants degradation. The improved CH(4) production was ascribed to the increases in fermentative-related bacteria (Smithella and Acetobacteroides), homoacetogen (Treponema), and methanogens. The increased abundances of anaerobic functional genes further verified the mechanism of CH(4) production. Furthermore, the abundances of potential hosts of antibiotic resistance genes (ARGs) were reduced under high nZVI concentration (1 g/L), contributing to ARGs attenuation. This study provides a comprehensive analysis of the mechanism in metabolic performance enhancement and ARGs attenuation during nZVI-assisted anaerobic CAP wastewater treatment. | 2021 | 34323729 |
| 7857 | 4 | 0.9995 | Electroactive Ultrafiltration Membrane for Simultaneous Removal of Antibiotic, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes from Wastewater Effluent. To combat the spread of antibiotic resistance into the environment, we should adequately manage wastewater effluent treatment to achieve simultaneous removal of antibiotics, antibiotic resistant bacteria (ARB), and antibiotic resistance genes (ARGs). Herein, we fabricate a multifunctional electroactive poly(vinylidene fluoride) ultrafiltration membrane (C/PVDF) by phase inversion on conductive carbon cloth. The membrane possesses not only excellent retention toward ARB and ARGs but also exhibits high oxidation capacity as an electrode. Notably, sulfamethoxazole degradation involving hydroxylation and hydrolysis by the anode membrane is predominant, and the degradation efficiency is up to 81.5% at +4 V. Both electro-filtration processes exhibit significant ARB inactivation, anode filtration is superior to cathode filtration. Moreover, the degradation of intracellular ARGs (iARGs) located in the genome is more efficient than those located in the plasmid, and these degradation efficiencies at -2 V are higher than +2 V. The degradation efficiencies of extracellular ARGs (eARGs) are opposite and are lower than iARGs. Compared with regular filtration, the normalized flux of electroactive ultrafiltration membrane is improved by 18.0% at -2 V, 15.9% at +2 V, and 30.4% at +4 V during treating wastewater effluent, confirming its antifouling properties and feasibility for practical application. | 2022 | 35613365 |
| 7827 | 5 | 0.9995 | Inactivation of antibiotic-resistant bacteria and antibiotic resistance genes by electrochemical oxidation/electro-Fenton process. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment are of great concern due to their potential risk to human health. The effluents from wastewater treatment plants and livestock production are major sources of ARB and ARGs. Chlorination, UV irradiation, and ozone disinfection cannot remove ARGs completely. In this study, the potential of electrochemical oxidation and electro-Fenton processes as alternative treatment technologies for inactivation of ARB and ARGs in both intracellular and extracellular forms was evaluated. Results showed that the electrochemical oxidation process was effective for the inactivation of selected ARB but not for the removal of intracellular ARGs or extracellular ARGs. The electro-Fenton process was more effective for the removal of both intracellular and extracellular ARGs. The removal efficiency after 120 min of electro-Fenton treatment under 21.42 mA/cm(2) was 3.8 logs for intracellular tetA, 4.1 logs for intracellular ampC, 5.2 logs for extracellular tetA, and 4.8 logs for extracellular ampC, respectively in the presence of 1.0 mmol/L Fe(2+). It is suggested that electrochemical oxidation is an effective disinfection method for ARB and the electro-Fenton process is a promising technology for the removal of both intracellular and extracellular ARGs in wastewater. | 2020 | 32701499 |
| 7914 | 6 | 0.9994 | Response of partial nitrification sludge to the single and combined stress of CuO nanoparticles and sulfamethoxazole antibiotic on microbial activity, community and resistance genes. Considering the inevitable release of antibiotics and nanoparticles (NPs) into the nitrogen containing wastewater, the combined impact of CuO NPs and sulfamethoxazole (SMX) antibiotic on partial nitrification (PN) process was investigated in four identical reactors. Results showed that the bioactivity of the aerobic ammonia-oxidizing bacteria (AOB) decreased by half after they were exposed to the combination of CuO NPs and SMX for short-term; however, there was no obvious variation in the bioactivity of AOB when they were exposed to either CuO NPs or SMX. During long-term exposure, the ammonia removal efficiency (ARE) of CuO NPs improved whereas that of SMX decreased, while the combination of CuO NPs and SMX significantly decreased ARE from 62.9% (in control) to 38.2% and had an unsatisfactory self-recovery performance. The combination of CuO NPs and SMX significantly changed the composition of microbial community, decreased the abundance of AOB, and significantly suppressed PN process. Reegarding the resistance genes, the CuO NPs-SMX combination did not improve the expression of copA, cusA, sul1 and sul2; however, it significantly induced the expression of sul3 and sulA. | 2020 | 32050397 |
| 8043 | 7 | 0.9994 | 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 |
| 7913 | 8 | 0.9994 | Response of the partial denitrification coupled with anaerobic ammonia oxidation system to disinfectant residues stress. The extensive use of disinfectants, especially NaClO, has resulted in chlorine disinfectant residues entering and impairing the biological treatment system. This study combined with long-term stress and transient shock of chlorine residues to comprehensively evaluate the variations of nitrogen removal performance, microbial community and antibiotic resistance genes composition in the PD/A system. The results showed that low concentration NaClO had no obvious harm to the system, but high concentration (>1 mg/L) NaClO would destroy the nitrogen removal performance of PD/A system. Interestingly, microorganisms in biofilm were more resistant to chlorine residues than that in sludge. Anaerobic ammonia oxidizing bacteria suffered more harm than denitrifying microorganisms, and chlorine residues mainly inhibited the process of converting N(2)H(4) to N(2) in anammox reaction. In addition, this study found that sludge showed a more significant increase in ARGs abundance and risk than biofilm. Moreover, risk assessments indicated that chlorine residues increased the risk of ARGs in PD/A systems. | 2025 | 40010223 |
| 7924 | 9 | 0.9994 | Electro-peroxone pretreatment for enhanced simulated hospital wastewater treatment and antibiotic resistance genes reduction. Hospital wastewater is one of the possible sources responsible for antibiotic resistant bacteria spread into the environment. This study proposed a promising strategy, electro-peroxone (E-peroxone) pretreatment followed by a sequencing batch reactor (SBR) for simulated hospital wastewater treatment, aiming to enhance the wastewater treatment performance and to reduce antibiotic resistance genes production simultaneously. The highest chemical oxygen demand (COD) and total organic carbon (TOC) removal efficiency of 94.3% and 92.8% were obtained using the E-peroxone-SBR process. The microbial community analysis through high-throughput sequencing showed that E-peroxone pretreatment could guarantee microbial richness and diversity in SBR, as well as reduce the microbial inhibitions caused by antibiotic and raise the amount of nitrification and denitrification genera. Specially, quantitative real-time PCRs revealed that E-peroxone pretreatment could largely reduce the numbers and contents of antibiotic resistance genes (ARGs) production in the following biological treatment unit. It was indicated that E-peroxone-SBR process may provide an effective way for hospital wastewater treatment and possible ARGs reduction. | 2018 | 29550711 |
| 8005 | 10 | 0.9994 | Deciphering the fate of antibiotic resistance genes in norfloxacin wastewater treated by a bio-electro-Fenton system. The misuse of antibiotics has increased the prevalence of antibiotic resistance genes (ARGs), considered a class of critical environmental contaminants due to their ubiquitous and persistent nature. Previous studies reported the potentiality of bio-electro-Fenton processes for antibiotic removal and ARGs control. However, the production and fate of ARGs in bio-electro-Fenton processes triggered by microbial fuel cells are rare. In this study, the norfloxacin (NFLX) average residual concentrations within two days were 2.02, 6.07 and 14.84 mg/L, and the average removal efficiency of NFLX was 79.8 %, 69.6 % and 62.9 % at the initial antibiotic concentrations of 10, 20 and 40 mg/L, respectively. The most prevalent resistance gene type in all processes was the fluoroquinolone antibiotic gene. Furthermore, Proteobacteria was the dominant ARG-carrying bacteria. Overall, this study can provide theoretical support for the efficient treatment of high antibiotics-contained wastewater by bio-electro-Fenton systems to better control ARGs from the perspective of ecological security. | 2022 | 36252757 |
| 7841 | 11 | 0.9994 | Simultaneous removal of antibiotics and antibiotic resistance genes in wastewater by a novel nonthermal plasma/peracetic acid combination system: Synergistic performance and mechanism. In this study, a novel and green method combining plasma with peracetic acid (plasma/PAA) was developed to simultaneously remove antibiotics and antibiotic resistance genes (ARGs) in wastewater, which achieves significant synergistic effects in the removal efficiencies and energy yield. At a plasma current of 2.6 A and PAA dosage of 10 mg/L, the removal efficiencies of most detected antibiotics in real wastewater exceeded 90 % in 2 min, with the ARG removal efficiencies ranging from 6.3 % to 75.2 %. The synergistic effects of plasma and PAA could be associated with the motivated production of reactive species (including •OH, •CH(3), (1)O(2), ONOO(-), •O(2)(-) and NO•), which decomposed antibiotics, killed host bacteria, and inhibited ARG conjugative transfer. In addition, plasma/PAA also changed the contributions and abundances of ARG host bacteria and downregulated the corresponding genes of two-component regulatory systems, thus reducing ARG propagation. Moreover, the weak correlations between the removal of antibiotics and ARGs highlights the commendable performance of plasma/PAA in the simultaneous removal of antibiotics and ARGs. Therefore, this study affords an innovative and effective avenue to remove antibiotics and ARGs, which relies on the synergistic mechanisms of plasma and PAA and the simultaneous removal mechanisms of antibiotics and ARGs in wastewater. | 2023 | 37027926 |
| 7919 | 12 | 0.9994 | Bioaugmentation using HN-AD consortia for high salinity wastewater treatment: Synergistic effects of halotolerant bacteria and nitrogen removal bacteria. Bioaugmentation shows promise in enhancing nitrogen removal efficiency of high-salt wastewater, yet the impact of microbial associations on ecosystem function and community stability remains unclear. This study innovatively introduced a novel heterotrophic nitrification-aerobic denitrification bacterial consortium to improve the performance of SBR reactor for removing nitrogen from saline wastewater. The results revealed that the bioaugmented reactor (R2) exhibited superior removal performance, achieving maximum removal efficiencies of 87.8 % for COD and 97.8 % for NH(4)(+)-N. Moreover, proper salinity (2 % and 4 %) promoted the secretion of EPS and ectoine, further enhancing the resistance and stability of bacterial consortia. 16S rRNA gene sequencing and metagenomics analysis revealed the key denitrifying bacteria Pseudomonas and salt-tolerant bacteria Halomonas were successfully coexistence and the relative abundances of crucial genes (napB, nirS, norB, norC and nosZ) were increased obviously, which were benefit for the excellent nitrogen removal performance in R2. These findings elucidate microbial interactions in response to salinity in bioaugmentation, providing a valuable reference for the efficient treatment of high-saline wastewater. | 2025 | 40233618 |
| 7903 | 13 | 0.9993 | Effects of zero-valent iron (ZVI) on nitrogen conversion, transformation of sulfamethoxazole (SMX) and abundance of antibiotic resistance genes (ARGs) in aerobic granular sludge process. Even after pre-treatment, livestock and poultry wastewater still contain high concentrations of ammonia and residual antibiotics. These could be removed economically using the aerobic granular sludge (AGS) process with zero-valent iron (ZVI). The interaction of antibiotics and nitrogen in this process needs to be clarified and controlled, however, to achieve good removal performance. Otherwise, antibiotics might generate transformation products (TPs) with higher toxicity and lead to the emergence of antibiotic-resistant bacteria carrying antibiotic resistance genes (ARGs), which could cause persistent toxicity and the risk of disease transmission to the ecological environment. This study investigated the impact of ZVI on AGS for nitrogen and sulfamethoxazole (SMX) removal. The results show that AGS could maintain good ammonia removal performance and that the existence of SMX had a negative impact on ammonia oxidation activities. ZVI contributed to an increase in the abundance of nitrite oxidation bacteria, denitrifying bacteria and the functional genes of nitrogen removal. This led to better total nitrogen removal and a decrease in N(2)O emission. Accompanied by biological nitrogen transformation, SMX could be transformed into 14 TPs through five pathways. ZVI has the potential to enhance transformation pathways with TPs of lower ecotoxicity, thereby reducing the acute and chronic toxicity of the effluent. Unfortunately, ZVI might enhance the abundance of sul1, sul2, and sul3 in AGS, which increases the risk of sulfonamide antibiotic resistance. In AGS, Opitutaceae, Xanthomonas, Spartobacteria and Mesorhizobium were potential hosts for ARGs. This study provides theoretical references for the interaction of typical antibiotics and nitrogen in the biological treatment process of wastewater and bioremediation of natural water bodies. | 2023 | 37832300 |
| 7837 | 14 | 0.9993 | Reducing the risk of exposure of airborne antibiotic resistant bacteria and antibiotic resistance genes by dynamic continuous flow photocatalytic reactor. In this study, based on the dynamic photocatalytic reactor constructed by the new photocatalyst TiO(2)/MXene, the purification process of different biological particles in aerosol was systematically studied. Multidrug resistant bacteria were easier to inactivate than common bacteria of the same kind, whether under UV conditions or photocatalysis. Photocatalyst was loaded on porous polyurethane sponge filler so that the combined effect of adsorption and advanced oxidation significantly improved the antibiotic resistant bacteria (ARB) disinfection effect. The inactivation efficiency of two ARBs under UV254 increased by 1.2 lg and 2.1 lg. In addition, it was found that the microorganisms treated by UV had slight self-repair phenomenon in a short time, while the microbial activity decreased continuously after photocatalysis. With the addition of photocatalyst, the particle size distribution of airborne Escherichia coli decreased and the micro morphology of cells was more seriously damaged. Antibiotic resistance genes (ARGs) carried by ARB can be dissociated into the environment after cell destruction, but it can be removed at a high level (sul2 can achieve 2.11 lg) in the continuous reactor at the same time. While avoiding secondary pollution, it also provides a powerful solution for airborne ARGs control. | 2022 | 35074752 |
| 7910 | 15 | 0.9993 | Tetracycline degradation by a mixed culture of halotolerant fungi-bacteria under static magnetic field: Mechanism and antibiotic resistance genes transfer. Efficient antibiotics removal lowers the transmission risk of antibiotic resistance genes (ARGs). However, low efficiency limits the application of biological methods for antibiotics removal. Herein, a mixed culture of halotolerant fungi-bacteria was used for treatment of saline wastewater containing tetracycline (TC). Furthermore, static magnetic field (SMF) was used to increase TC removal. The study examined the effectiveness of SMF in removing antibiotics from saline wastewater and the associated risk of ARGs transmission. The results demonstrated that the application of a 40 mT SMF significantly improved the TC removal efficiency by 37.09 %, compared to the control (SMF=0) The TC was mainly removed through biodegradation and adsorption. In biodegradation, SMF enhanced electron transport system activity, and activities of lignin-degrading enzymes which led to higher TC biodegradation. The activity of lactate dehydrogenase and malondialdehyde decreased, lowering the damage of microbial cell membranes by TC. During the adsorption process, higher generation of extracellular polymeric substances was observed under SMF, which caused an increase in TC removal via adsorption. Microbial community analysis revealed that SMF facilitated the enrichment of TC-degrading microorganisms. Under SMF, vertical gene transfer of ARGs increased, while horizontal gene transfer risk decreased due to a reduction in mobile genetic elements (intl1) abundance. This study demonstrates that SMF is a promising strategy for enhancing TC removal efficiency, providing a basis for improved antibiotic wastewater management. | 2025 | 40199074 |
| 7906 | 16 | 0.9993 | Mechanisms of metabolic performance enhancement during electrically assisted anaerobic treatment of chloramphenicol wastewater. The anaerobic process is a favorable alternative for the treatment of antibiotic pharmaceutical wastewater. The electrically assisted anaerobic process can be used to accelerate contaminant removal, especially for persistent organic pollutants such as antibiotics. In this study, an electrically assisted anaerobic system for chloramphenicol (CAP) wastewater treatment was developed. The system performance and the underlying metabolic mechanisms were evaluated under different applied voltages. With the increase of applied voltage from 0 to 2 V, the CAP removal efficiencies increased from 53.3% to 89.7%, while the methane production increased more than three times. The microbial community structure and correlation analysis showed that electrical stimulation selected the dominant functional bacteria and increased antibiotic resistance in dominant functional bacteria, both of which enhanced CAP removal and methane production. The improved CAP removal was a result of the presence of dechlorination-related bacteria (Acidovorax, Sedimentibacter, Thauera, and Flavobacterium) and potential electroactive bacteria (Shewanella and Comamonas), both of which carried ARGs and therefore could survive the biotoxicity of CAP. The enhanced methane production could be partly attributed to the surviving fermentative-related bacteria (Paludibacter, Proteiniclasticum, and Macellibacteroides) in the anaerobic bioreactor. The increased abundances of methanogenic genes (mcrA and ACAS genes) under high voltage further confirmed the enhanced methane production of this electrically assisted anaerobic system. The fundamental understanding of the mechanisms underlying metabolic performance enhancement is critical for the further development of anaerobic wastewater treatment. | 2019 | 30917300 |
| 7902 | 17 | 0.9993 | Determination of the lower limits of antibiotic biodegradation and the fate of antibiotic resistant genes in activated sludge: Both nitrifying bacteria and heterotrophic bacteria matter. Antibiotics can be biodegraded in activated sludge via co-metabolism and metabolism. In this study, we investigated the biodegradation pathways of sulfamethoxazole (SMX) and antibiotic resistant genes' (ARGs) fate in different autotrophic and heterotrophic microorganisms, by employing aerobic sludge, mixed sludge, and nitrifying sludge. A threshold concentration of SMX activating the degradation pathways in the initial stage of antibiotics degradation was found and proved in different activated sludge systems. Heterotrophic bacteria played an important role in SMX biodegradation. However, ammonia-oxidizing bacteria (AOB) had a faster metabolic rate, which was about 15 times higher than heterotrophic bacteria, contributing much to SMX removal via co-metabolism. As SMX concentration increases, the amoA gene and AOB relative abundance decreased in aerobic sludge due to the enrichment of functional heterotrophic bacteria, while it increased in nitrifying sludge. Microbial community analysis showed that functional bacteria which possess the capacity of SMX removal and antibiotic resistance were selected by SMX pressure. Potential ARGs hosts could increase their resistance to the biotoxicity of SMX and maintain system performance. These findings are of practical significance to guide antibiotic biodegradation and ARGs control in wastewater treatment plants. | 2022 | 34799165 |
| 7918 | 18 | 0.9993 | Robustness of the partial nitrification-anammox system exposing to triclosan wastewater: Stress relieved by extracellular polymeric substances and resistance genes. The partial nitrification-anammox (PN/A) process is a promising method for the treatment of municipal wastewater. It is necessary to clarify the responses of PN/A system to antimicrobial agent triclosan (TCS) widely existed in the influent of wastewater treatment plants. In this study, it was found that PN/A system was robust to cope with 0.5 mg/L TCS. Specifically, the control reactor reached 80% total nitrogen removal efficiency (TNRE) on day 107, while the reactor feeding with 0.5 mg/L TCS reached the same TNRE on day 84. The results of the activity test, high-throughput sequencing and DNA-based stable isotope probing showed that 0.5 mg/L TCS did not impede the performance of ammonia oxidizing archaea, ammonia oxidizing bacteria (Nitrosomonas) and anammox bacteria (Candidatus Brocadia and Ca. Kuenenia), but significant inhibited the nitrite oxidizing bacteria (Nitrospira and Ca. Nitrotoga) and denitrifying bacteria. The influent TCS led to the increase of EPS content and enrichment of four resistance genes (RGs) (intI1, sul1, mexB, and tnpA), which might be two principal mechanisms by which PN/A can resist TCS. In addition, functional bacteria carrying multiple RGs also contributed to the maintenance of PN/A system function. These findings improved the understandings of antimicrobial effects on the PN/A system. | 2022 | 34954146 |
| 7915 | 19 | 0.9993 | Deciphering antibiotic resistance genes and microbial community of anammox consortia under sulfadiazine and chlortetracycline stress. The responses of anammox consortia to typical antibiotics sulfadiazine (SDZ) and chlortetracycline (CTC) were evaluated on the aspects of general performance, microbial activity, diversity and abundance of antibiotic resistance genes (ARGs), and microbial host of ARGs in anammox system. Results showed the anammox consortia had a stable performance and great resistance to 10 mg/L of SDZ, while 1 mg/L of CTC induced an unrecoverable inhibitory influence on nitrogen removal performance and anammox activity without any special treatment. The absolute abundances of anammox functional genes (nirS, hzsA and hdh) were stimulated by the acclimation to SDZ stress, however, they were much lower than the initial levels under CTC stress. In anammox consortia, ARGs comprised 18 types (94 subtypes) derived from over 20 genera. Strikingly, the anammox bacteria (AnAOB) "Ca. Brocadia" occupied 46.81% of the SDZ resistance genes (sul1 and sul2) and 38.63% of CTC resistance genes (tetX, tetG and rpsJ), and thus were identified as the dominant antibiotic resistance bacteria (ARB). Therefore, harboring the corresponding ARGs by AnAOB could be the primary protective mechanism to interpret the resistance of anammox consortia to antibiotics stress. Meanwhile, co-occurring of ARGs in anammox consortia suggested the synergistic cooperation of different ARGs could be an essential strategy to alleviate the SDZ and CTC stress. The present study proposed a new interpretation of possible mechanism that cause antibiotic resistance of anammox consortia. | 2022 | 35259594 |