How anammox process resists the multi-antibiotic stress: Resistance gene accumulation and microbial community evolution.

The effects of multiple antibiotics on the anaerobic ammonia oxidation (anammox) process were investigated. The resistance of the anammox system to high-concentration antibiotics was also demonstrated through gradual acclimation experiments. Inhibition of the anammox process (R) occurred when the concentrations of erythromycin (ERY), sulfamethoxazole (SMX) and tetracycline (TC) were 0.

Exogenous extracellular polymeric substances as protective agents for the preservation of anammox granules.

The preservation of anammox granules is of great significance for the rapid start-up of the anammox process and improvement of performance stability. Therefore, it is necessary to explore an economical and stable preservation strategy. Exogenous extracellular polymeric substances (EPS) were used as protective agents for the preservation of anammox granules in this study.

Deciphering 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.

Microbial community evolution and fate of antibiotic resistance genes in anammox process under oxytetracycline and sulfamethoxazole stresses.

The microbial community characteristics, functional and antibiotic resistance genes (ARGs), anammox performance under individual and combined oxytetracycline (OTC) and sulfamethoxazole (SMX) were tested under environmentally relevant levels. The results showed that anammox performance was inhibited when the OTC or SMX concentration increased from 0.5 to 1.

Deciphering the microbial and genetic responses of anammox biogranules to the single and joint stress of zinc and tetracycline.

The feasibility of using anaerobic ammonium oxidation (anammox) process to treat wastewaters containing antibiotics and heavy metals was evaluated in this study. The nitrogen removal performance and characteristic parameters were monitored during the whole experimental period of 258 d. The single and joint effects of zinc and tetracycline on the microbial community were studied in upflow anaerobic sludge blanket (UASB) reactors.

Expression of the nirS, hzsA, and hdh genes and antibiotic resistance genes in response to recovery of anammox process inhibited by oxytetracycline.

The inhibitory effects of oxytetracycline (OTC) on the anaerobic ammonium oxidation (anammox) performance were relieved by employing bio-augmentation (BA) tactics. However, the recovery mechanism was vague. The response of specific anammox activity (SAA), heme c, functional genes, extracellular polymeric substance (EPS) and antibiotics resistance genes (ARGs) to OTC inhibition and BA aid were traced in the present study.

Whether glycine betaine improves the thermotolerance of mesophilic anammox consortia.

While the application of mesophilic anammox process is currently the state of the art, the feasibility of a thermophilic anammox bioprocess is still unclear. In this study, we investigate whether glycine betaine (GB) addition can enhance the thermotolerance of mesophilic anammox biomass in the upflow anaerobic sludge blanket (UASB) reactors fed with synthetic wastewater at a nitrogen loading of approximately 4 kg N m d. The results showed that during a long-term operation at 45°C with GB (0, 0.

Discrepant effects of metal and metal oxide nanoparticles on anammox sludge properties: A comparison between Cu and CuO nanoparticles.

Metal and metal oxide nanoparticles (NPs) show differences in antimicrobial activity due to different chemical and physical properties. Using copper as a representative example, this study compared the NP effects on anaerobic ammonium oxidation (anammox) bacteria in wastewater treatment. Long-term exposure to 5 mgCu L CuNPs reduced the physiological activity and abundance of anammox bacteria, thereby causing deterioration of reactor performance.

Evaluating the effects of metal oxide nanoparticles (TiO, AlO, SiO and CeO) on anammox process: Performance, microflora and sludge properties.

The increasing use of engineered metal oxide nanoparticles (MONPs) in consumer products raises great concerns about their environmental impacts, but their potential impacts on anaerobic ammonium oxidation (anammox) process in wastewater treatment remain unclear. In this study, the presence of MONPs (1, 50, 200 mg L) exhibited no visible effects on the nitrogen removal performance of anammox reactors, but high levels (200 mg L) of SiONPs, AlONPs and CeONPs had a distinct effect on shaping the anammox community. Long-term exposure of MONPs caused different responses in the relative abundance of Ca.

Effect of chromium on granule-based anammox processes.

In this study, the feasibility of application of anaerobic ammonium oxidation (anammox) to teat wastewater containing chromium was assessed. Anammox granule activity decreased with increasing Cr(VI) concentration and pre-exposure time in batch tests, and the 50% inhibition concentration of Cr(VI) on anammox biomass was 296.5 mg L.

Anammox granules show strong resistance to engineered silver nanoparticles during long-term exposure.

The increasing use of engineered Ag nanoparticles (NPs) in consumer products raises great concerns about their environmental impacts, but their potential impact on anaerobic ammonium oxidation (anammox) bacteria in wastewater treatment remains unclear. In this study, the response of anammox consortia inhabiting in granules to long-term exposure of AgNPs was investigated. The gradually increased stress of AgNPs (1, 10, 50 mg L) showed no adverse effects on the nitrogen removal performance and on the relative abundance of Ca.

Transient disturbance of engineered ZnO nanoparticles enhances the resistance and resilience of anammox process in wastewater treatment.

The increasing use of engineered nanoparticles (NPs) in consumer and industrial products raises concerns about their environmental impacts, but their potential influence on anaerobic ammonium oxidation (anammox) process in wastewater treatment remains unknown. In this study, the response of granule-based anammox reactor to different loads of ZnONPs was investigated. The introduction of 1-5mgL ZnONPs did not affect reactor performance, but 90% of the nitrogen removal capacity was deprived by a shock of 10mgL ZnONPs within 3days.

Enhanced effects of maghemite nanoparticles on the flocculent sludge wasted from a high-rate anammox reactor: Performance, microbial community and sludge characteristics.

Magnetic nanoparticles (NPs) have been widely applied in environmental remediation, biomass immobilization and wastewater treatment, but their potential impact on anaerobic ammonium oxidation (anammox) biomass remains unknown. In this study, the short-term and long-term impacts of maghemite NPs (MHNPs) on the flocculent sludge wasted from a high-rate anammox reactor were investigated. Batch assays showed that the presence of MHNPs up to 200 mg L did not affect anammox activity, reactive oxygen species production, or cell membrane integrity.

Unraveling the impact of nanoscale zero-valent iron on the nitrogen removal performance and microbial community of anammox sludge.

Given the increasing use of nanoscale zero-valent iron (NZVI) particles for environmental remediation and wastewater treatment, their potential impact on anaerobic ammonium oxidation (anammox) bacteria was investigated in this study using anammox sludge. Batch assays showed that NZVI concentrations up to 200mgL did not affect anammox activity, reactive oxygen species production, and cell membrane integrity. The nitrogen removal efficiency of the continuous-flow reactor fluctuated in the presence of 20 or 50mgL NZVI, but it could return to normal over time, even at 200mgL NZVI.

Ultrasensitive electrochemical detection of DNA hybridization using Au/Fe3O4 magnetic composites combined with silver enhancement.

A novel method is described for the highly effective amplifying electrochemical response of DNA based on oligonucleotides functionalized with Au/Fe(3)O(4) nanocomposites by the aid of silver (Ag) enhancement. Via electrostatic layer-by-layer (LBL) assembly, the prepared Fe(3)O(4) nanoparticles form nano-clusters coated with a bilayer composed of polystyrene sulfonate sodium salt (PSS) and poly(diallyldimethylammonium chloride) (PDDA), which are in favor of adsorbing lots of gold nanoparticles (AuNPs) on the surface. The application of magnetic Fe(3)O(4) made the procedures much more simple, convenient and feasible.

Selective sensing of cysteine on manganese dioxide nanowires and chitosan modified glassy carbon electrodes.

We report a simple approach for the selectively electrochemical sensing of cysteine (CySH) using beta-MnO(2) nanowires modified glassy carbon (GC) electrode via a direct and facile electrochemical co-deposition process with chitosan hydrogel. The electrode showed excellent electrocatalytic effect toward cysteine oxidation. A possible reaction mechanism related to the formation of surface complexes was proposed: the -SH group is the reacting group in the reaction between cysteine and MnO(2), while the -NH(2) group acts as an anchor to stabilize the surface complexes.