A fluorescent terbium-metal-organic framework material for high-sensitivity detection of vomitoxin and oxytetracycline hydrochloride in water.

A unique luminescent lanthanide metal-organic framework (LnMOF)-based fluorescence detection platform was utilized to achieve sensitive detection of vomitoxin (VT) and oxytetracycline hydrochloride (OTC-HCL) without the use of antibodies or biomolecular modifications. The sensor had a fluorescence quenching constant of 9.74 × 106 M-1 and a low detection limit of 0.68 nM for vomitoxin. Notably, this is the first example of a Tb-MOF sensor for fluorescence detection of vomitoxin. We further investigated its response to two mycotoxins, aflatoxin B1 and ochratoxin A, and found that their Stern-Volmer fluorescence quenching constants were lower than those of VT. In addition, the fluorescence sensor realized sensitive detection of OTC-HCL with a detection limit of 0.039 µM. In conclusion, the method has great potential as a sensitive and simple technique to detect VT and OTC-HCL in water.

Assessment of antibiotic residues in chicken meat.

Background: Nowadays veterinarians and poultry producers use antibiotics to increase growth rates, bird health, and feed efficiency, egg production, for preventative and therapeutic purposes, and to lessen the prevalence of poultry diseases. Most poultry producers have used a variety of antibiotics, either with or without veterinarian instruction. Although antibiotics are beneficial for the majority of their uses, their unauthorized use has resulted in residues accumulated in poultry products intended for human consumption which represents a serious risk to the general public that could be toxicological, microbiological, or immunological. Aim: This study aimed to the estimation of the residues of three major antimicrobials used in the intensive chicken-rearing systems in Egypt, namely Oxytetracycline (OTC), Gentamicin, and Ciprofloxacin. Moreover, the effect of cooking on such residues was investigated. Methods: A total of 100 chicken meat samples (breast, thigh, gizzard, liver, 25 each) were examined for detection of the aforementioned antimicrobials using the microbial inhibition assay and high-performance liquid chromatography (HPLC). Besides, samples containing the highest antimicrobial residues were examined for the effect of boiling for 30 minutes on such residues. Results: The obtained results revealed that 23%, 21%, and 17% of the examined samples were positive for OTC, gentamicin, and ciprofloxacin residues , respectively . Cooking (boiling) for 30 minutes showed a reduction of the antibiotic residue by 88.2%, 95.2%, and 31.3%, respectively. Conclusion: Antimicrobial residues were detected in the chicken meat parts retailed in Egypt. Cooking can reduce the antimicrobial residues at least in part.

Changes in bacterial community composition in the uterus of Holstein cow with endometritis before and after treatment with oxytetracycline.

It is important to study the bacteria that cause endometritis to identify effective therapeutic drugs for dairy cows. In this study, 20% oxytetracycline was used to treat Holstein cows (n = 6) with severe endometritis. Additional 10 Holstein cows (5 for healthy cows, 5 for cows with mild endometritis) were also selected. At the same time, changes in bacterial communities were monitored by high-throughput sequencing. The results show that Escherichia coli, Staphylococcus aureus and other common pathogenic bacteria could be detected by traditional methods in cows both with and without endometritis. However, 16S sequencing results show that changes in the abundance of these bacteria were not significant. Endometritis is often caused by mixed infections in the uterus. Oxytetracycline did not completely remove existing bacteria. However, oxytetracycline could effectively inhibit endometritis and had a significant inhibitory effect on the genera Bacteroides, Trueperella, Peptoniphilus, Parvimonas, Porphyromonas, and Fusobacterium but had no significant inhibitory effect on the bacterial genera Marinospirillum, Erysipelothrix, and Enteractinococcus. During oxytetracycline treatment, the cell motility, endocrine system, exogenous system, glycan biosynthesis and metabolism, lipid metabolism, metabolism of terpenoids, polyketides, cofactors and vitamins, signal transduction, and transport and catabolism pathways were affected.

Combined effects of azoxystrobin and oxytetracycline on rhizosphere microbiota of Arabidopsis thaliana.

The rhizosphere is one of the key determinants of plant health and productivity. Mixtures of pesticides are commonly used in intensified agriculture. However, the combined mechanisms underlying their impacts on soil microbiota remain unknown. The present study revealed that the rhizosphere microbiota was more sensitive to azoxystrobin and oxytetracycline, two commonly used pesticides, than was the microbiota present in bulk soil. Moreover, the rhizosphere microbiota enhanced network complexity and stability and increased carbohydrate metabolism and xenobiotic biodegradation as well as the expression of metabolic genes involved in defence against pesticide stress. Co-exposure to azoxystrobin and oxytetracycline had antagonistic effects on Arabidopsis thaliana growth and soil microbial variation by recruiting organic-degrading bacteria and regulating ABC transporters to reduce pesticide uptake. Our study explored the composition and function of soil microorganisms through amplicon sequencing and metagenomic approaches, providing comprehensive insights into the synergistic effect of plants and rhizosphere microbiota on pesticides and contributing to our understanding of the ecological risks associated with pesticide use.

Effect of microplastics on oxytetracycline trophic transfer: Immune, gut microbiota and antibiotic resistance gene responses.

Microplastics and antibiotics are prevalent and emerging pollutants in aquatic ecosystems, but their interactions in aquatic food chains remain largely unexplored. This study investigated the impact of polypropylene microplastics (PP-MPs) on oxytetracycline (OTC) trophic transfer from the shrimp (Neocaridina denticulate) to crucian carp (Carassius auratus) by metagenomic sequencing. The carrier effects of PP-MPs promoted OTC bioaccumulation and trophic transfer, which exacerbated enterocyte vacuolation and hepatocyte eosinophilic necrosis. PP-MPs enhanced the inhibitory effect of OTC on intestinal lysozyme activities and complement C3 levels in shrimp and fish, and hepatic immunoglobulin M levels in fish (p < 0.05). Co-exposure of MPs and OTC markedly increased the abundance of Actinobacteria in shrimp and Firmicutes in fish, which caused disturbances in carbohydrate, amino acid, and energy metabolism. Moreover, OTC exacerbated the enrichment of antibiotic resistance genes (ARGs) in aquatic animals, and PP-MPs significantly increased the diversity and abundance of ARGs and facilitated the trophic transfer of teta and tetm. Our findings disclosed the impacts of PP-MPs on the mechanism of antibiotic toxicity in aquatic food chains and emphasized the importance of gut microbiota for ARGs trophic transfer, which contributed to a deeper understanding of potential risks posed by complex pollutants on aquatic ecosystems.

Biofilm enhances the interactive effects of microplastics and oxytetracycline on zebrafish intestine.

The enhanced adsorption of pollutants on biofilm-developed microplastics has been proved in many studies, but the ecotoxicological effects of biofilm-developed microplastics on organisms are still unclear. In this study, adult zebrafish were exposed to original microplastics, biofilm-developed microplastics, original microplastics absorbed with oxytetracycline (OTC), and biofilm-developed microplastics absorbed with OTC for 30 days. The intestinal histological damage, intestinal biomarker response, gut microbiome and antibiotic resistance genes (ARGs) profile of zebrafish were measured to explore the roles of biofilm in the effects of microplastics. The results showed that biofilm-developed microplastics significantly increased the number of goblet cells in intestinal epithelium compared with the control group. The biofilm-developed microplastics also induced the oxidative response in the zebrafish intestines, and biofilm changed the response mode in the combined treatment with OTC. Additionally, the biofilm-developed microplastics caused intestinal microbiome dysbiosis, and induced the abundance of some pathogenic genera increasing by several times compared with the control group and the original microplastics treatments, regardless of OTC adsorption. Furthermore, the abundance of ARGs in biofilm-developed microplastics increased significantly compared with the control and the original microplastic treatments. This study emphasized the significant influence and unique role of biofilm in microplastic studies.

One Health-based management for sustainably mitigating tetracycline-resistant Aeromonas hydrophila-induced health risk.

Aeromonas hydrophila has ability to spread tetracycline resistance (tetR) under stresses of oxytetracycline (OTC), one of the most important antibiotics in aquaculture industry. Even though environmental reservoir of Aeromonas allows it to be at interfaces across One Health components, a robust modelling framework for rigorously assessing health risks is currently lacking. We proposed a One Health-based approach and leveraged recent advances in quantitative microbial risk assessment appraised by available dataset to interpret interactions at the human-animal-environment interfaces in various exposure scenarios. The dose-response models were constructed considering the effects on mortality for aquaculture species and tetR genes transfer for humans. A scenario-specific risk assessment on pond species-associated A. hydrophila infection and human gut-associated tetR genes transfer was examined. Risk-based control strategies were involved to test their effectiveness. We showed that farmed shrimp exposed to tetracycline-resistant A. hydrophila in OTC-contaminated water experienced higher infection risk (relative risk: 1.25-1.34). The tetR genes transfer risk for farmers in shrimp ponds (∼2 × 10-4) and swimmers in coastal areas (∼4 × 10-6) during autumn exceeded acceptable risk (10-6). This cautionary finding underscores the importance of accounting for monitoring, assessing, and mitigating occupational health hazards among workers in shrimp farming sectors within future One Health-based strategies for managing water infection risks. We recommend that OTC emission rate together with A. hydrophila concentration should be reduced by up to 70-99% to protect human, farmed shrimp, and environmental health. Our predictive framework can be adopted for other systems and be used as a "risk detector" for assessing tetR-related health risks that invoke potential risk management on addressing sustainable mitigation on offsetting residual OTC emission and tetR genes spread in a species-human-environmental health system.

Differential effects of oxytetracycline on detoxification and antioxidant defense in the hepatopancreas and intestine of Chinese mitten crab under cadmium stress.

This study aims to evaluate the effects of oxytetracycline (OTC) on detoxification and oxidative defense in the hepatopancreas and intestine of Chinese mitten crab (Eriocheir sinensis) under cadmium (Cd) stress. The crab was exposed to 0.6 µM Cd, 0.6 µM OTC, and 0.6 µM Cd plus 0.6 µM OTC for 42 days. Our results showed that in the intestine, OTC alone enhanced protein carboxylation (PC) and malondialdehyde (MDA) contents, which was associated with the increased OTC accumulation. Compared to Cd alone, Cd plus OTC increased Cd and OTC contents, and reduced detoxification (i.e., glutathione (GSH) content, gene expressions of cytochrome P450 (CYP) isoforms, 7-ethoxyresorufin O-deethylase (EROD) activity, mRNA levels and activities of glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)), and antioxidant defense (i.e., gene expressions and activities of catalase (CAT) and superoxide dismutase (SOD)) in the intestine, leading to the increased in PC and MDA contents, suggesting that OTC had a synergistic effect on Cd-induced oxidative damage. In the hepatopancreas, although OTC alone increased OTC accumulation, it did not affect PC and MDA contents. Compared to Cd alone, Cd plus OTC reduced MDA content, which was closely related to the improvement of detoxification (i.e., GSH content, mRNA levels of CYP isoforms, EROD activity, gene expressions and activities of GPx, GR and GST), and antioxidant defense (gene expressions and activities of CAT and SOD, metallothionein content). Aryl hydrocarbon receptor (AhR) and nuclear factor E2-related factor 2 (Nrf2) transcriptional expressions were positively correlated with most detoxification- and antioxidant-related gene expressions, respectively, indicating that AhR and Nrf2 were involved in the regulation of these gene expressions. Our results unambiguously demonstrated that OTC had tissue-specific effects on Cd-induced toxicological effect in E. sinensis, which contributed to accurately evaluating Cd toxicity modulated by TCs in crab.

Oxytetracycline Increases the Residual Risk of Imidacloprid in Radish (Raphanus sativus) and Disturbs the Plant-Rhizosphere Microbiome Holobiont Homeostasis.

Antibiotics can be accidentally introduced into farmland by wastewater irrigation, and the environmental effects are still unclear. In this study, the effects of oxytetracycline on the residue of imidacloprid in soil and radishes were investigated. Besides, the rhizosphere microbiome and radish metabolome were analyzed. It showed that the persistence of imidacloprid in soil was unchanged, but the content of olefin-imidacloprid was increased by oxytetracycline. The residue of imidacloprid in radishes was increased by nearly 1.5 times, and the hazard index of imidacloprid was significantly raised by 1.5-4 times. Oxytetracycline remodeled the rhizosphere microbiome, including Actinobe, Elusimic, and Firmicutes, and influenced the metabolome of radishes. Especially, some amino acid metabolic pathways in radish were downregulated, which might be involved in imidacloprid degradation. It can be assumed that oxytetracycline increased the imidacloprid residue in radish through disturbing the plant-rhizosphere microbiome holobiont and, thus, increased the pesticide dietary risk.

Liver histopathological and oxidative stress assessment by a combination of formaldehyde and oxytetracycline in sea bass (Dicentrarchuslabrax L).

Background: Formaldehyde (FA) and oxytetracycline (OTC) are the chemicals commonly used in aquaculture to prevent or treat fish diseases due to protozoa, parasites, and bacteria. Aim: The goal of the present study is to assess the liver injury and oxidative stress induced by exposure of sea bass (Dicentrarchuslabrax L) to therapeutic doses of FA (200 ml.m-3) and OTC (40 g.m-3) under the same conditions being applied in intensive aquaculture systems in Tunisia. Methods: The liver histopathological survey was achieved after 5 and 10 days of exposure to FA, OTC separately or mixed. In parallel, liver catalase activity and malondialdehyde (MDA) were measured to assess oxidative stress. Results: Results showed that treatment with FA and OTC used alone or in combinations induced liver damage as measured by sinusoid dilatation, intensive vacuolization, blood congestion, and focal necrosis. Significant elevation in catalyze activity and MDA levels were also observed in liver homogenates by the treatment (p ≤ 005). Conclusion: Combined treatment induced higher effects suggesting the critical hazards associated with FA and OTC when released to the environment.

Z-scheme heterojunction photocatalyst formed by MOF-derived C-TiO2 and Bi2WO6 for enhancing degradation of oxytetracycline: Mechanistic insights and toxicity evaluation in the presence of a single active species.

In the work, Bi2WO6/C-TiO2 photocatalyst was successfully synthesized for the first time by loading narrow bandgap semiconductor Bi2WO6 on MOF-derived carboxyl modified TiO2. The phase structure, morphology, photoelectric properties, surface chemical states and photocatalytic performance of the prepared photocatalysts were systematically investigated using various characterization tools. The degradation efficiency of oxytetracycline by 6BT Z-scheme heterojunction photocatalyst under visible light could reach 93.6 % within 100 min, which was related to the high light harvesting and effective separation and transfer of photo-generated carriers. Furthermore, the effects of various environmental factors in actual wastewater were further investigated, and the results showed that 6BT exhibited good adaptability, durability and resistance to interference. Unlike most works, the degradation system with a different single active species were designed and constructed based on their formation mechanism. In addition, for the first time, a positive study was conducted on the priority attack sites, intermediate products, and degradation pathways for the photocatalytic degradation of oxytetracycline by a single active species through HPLC-MS and Fukui index calculations. The toxicity changes of intermediate products produced in three different single active species oxidation systems were evaluated using toxicity assessment software tools (T.E.S.T.), Escherichia coli growth experiments, and wheat growth experiments. Among them, the intermediate products formed through O2- oxidation had the lowest toxicity and the main active sites it attacked were the 20C, 38O, 18C, 41O, and 55O atoms with high f+ values in the oxytetracycline molecular structure. This work provided the insight into the role of each active species in the degradation of antibiotics and offered new ideas for the design and synthesis of efficient and eco-friendly photocatalysts.

Borophene Quantum Dots as Novel Peroxidase-Mimicking Nanozyme: A Dual-Mode Assay for the Detection of Oxytetracycline and Tetracycline Antibiotics.

The greater advantages and wide applications of zero-dimensional nanodots inspire researchers to develop new materials. Therefore, novel borophene quantum dots (QDs) were prepared by a hydrothermal liquid exfoliation technique using water medium. The borophene QDs proved to be highly stable in water medium for more than 120 days. The synthesized borophene QDs revealed intrinsic peroxidase mimetic activity using two chromogenic substrates, 3,3',5,5'-tetramethylbenzidine (TMB) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS). The excellent intrinsic peroxidase activity toward TMB and ABTS substrates was executed using optimal reaction conditions (pH, borophene QDs' concentration, incubation time, and temperature). The formation of hydroxyl radicals in the presence of H2O2 upon TMB and ABTS oxidation played a significant role in the peroxidase reaction. The borophene QDs further proved to be successful for the colorimetric detection of antibiotics (oxytetracycline and tetracycline) using both TMB and ABTS peroxidase substrates. The limit of detection (LOD) for oxytetracycline and tetracycline was found to be 1.10 and 1.02 µM using TMB and 1.03 and 1.02 µM using ABTS chromogenic substrates, respectively. In addition, the fluorescence sensing of oxytetracycline and tetracycline over borophene QDs was also examined. The high fluorescence of borophene QDs (turn ON) was quenched (turn OFF) by oxytetracycline and tetracycline through the inner filter effect mechanism. The LOD of the fluorescence sensing of oxytetracycline and tetracycline was 1.14 and 1.08 µM, respectively. Interestingly, the borophene QDs could be used for the sensitive and selective colorimetric and fluorometric sensing of oxytetracycline and tetracycline after 120 days of storage. The synthesized borophene QDs with long-term stability and real sample analysis provide new insight as nanozymes with higher peroxidase mimetic and fluorescence performance and can be further exploited for medical diagnosis and environmental toxicants' detection.

Ecotoxicity of five veterinary antibiotics on indicator organisms and water and soil communities.

This study explores the environmental effects of five common veterinary antibiotics widely detected in the environment, (chlortetracycline,CTC; oxytetracycline,OTC; florfenicol,FF; neomycin, NMC; and sulfadiazine, SDZ) on four bioindicators: Daphnia magna, Vibrio fischeri, Eisenia fetida, and Allium cepa, representing aquatic and soil environments. Additionally, microbial communities characterized through 16 S rRNA gene sequencing from a river and natural soil were exposed to the antibiotics to assess changes in population growth and metabolic profiles using Biolog EcoPlates™. Tetracyclines are harmful to Vibrio fisheri (LC50 ranges of 15-25 µg/mL), and the other three antibiotics seem to only affect D. magna, especially, SDZ. None of the antibiotics produced mortality in E. fetida at concentrations below 1000 mg/kg. NMC and CTC had the highest phytotoxicities in A. cepa (LC50 = 97-174 µg/mL, respectively). Antibiotics significantly reduced bacterial metabolism at 0.1-10 µg/mL. From the highest to the lowest toxicity on aquatic communities: OTC > FF > SDZ ≈ CTC > NMC and on edaphic communities: CTC ≈ OTC > FF > SDZ > NMC. In river communities, OTC and FF caused substantial decreases in bacterial metabolism at low concentrations (0.1 µg/mL), impacting carbohydrates, amino acids (OTC), and polymers (FF). At 10 µg/mL and above, OTC, CTC, and FF significantly decreased metabolizing all tested metabolites. In soil communities, a more pronounced decrease in metabolizing ability, detectable at 0.1 µg/mL, particularly affected amines/amides and carboxylic and ketonic acids (p < 0.05). These new ecotoxicity findings underscore that the concentrations of these antibiotics in the environment can significantly impact both aquatic and terrestrial ecosystems.

Colorimetric aptasensor utilizing MOF-235 with exceptional peroxidase-like activity for the detection of oxytetracycline residues in raw milk.

In this work, a simple, convenient and cost-effective colorimetric aptasensor was successfully constructed for the detection of antibiotic residues in raw milk based on the property that aptamer (Apt) synergistically enhances the catalase-like activity of MOF-235. Under optimised conditions, the proposed colorimetric aptasensor exhibited a wide detection range (15-1500 nM) with a low detection limit (6.92 nM). Furthermore, the proposed aptasensor demonstrated high selectivity, good resistance to interference and storage stability. The proposed aptasensor was validated by spiking recovery in camel milk, cow milk and goat milk with satisfactory recoveries, which demonstrated the great potential of the aptasensor for further application in real food samples, and also suggested that MOF-235 can be used as a potential universal platform to build a sensitive detection platform for other targets.

High enrichment and sensitive measurement of oxytetracycline in tea drinks by thermosensitive magnetic molecular imprinting based magnetic solid phase extraction coupled with boron doped carbon dots.

As a typical kind of new pollutants, there are still some challenges in the rapid detection of antibiotics. In this work, a sensitive fluorescent probe based on boron-doped carbon dots (B-CDs) in combination with thermo-responsive magnetic molecularly imprinted polymers (T-MMIPs) was constructed for the detection of oxytetracycline (OTC) in tea drinks. T-MMIPs were designed, fabricated and employed to enrich OTC at trace level from tea drinks, and B-CDs were utilized as the fluorescent probe to detect the concentration of OTC. The proposed method exhibited good linear relationship with OTC concentration from 0.2 to 60 µg L-1 and the limit of detection was 0.1 µg L-1. The established method has been successfully validated with tea beverages. Present work was the first attempt application of T-MMIPs in combination with CDs in detection of OTC, and demonstrated that the proposed method endowed the detection of OTC with high selectivity, sensitivity, reliability and wide application prospect, meanwhile offered a new strategy for the method establishment of rapid and sensitive detection of trace antibiotics in food and other matrices.

A new PdMOF-loaded molecularly imprinted polyaniline nanocatalytic probe for ultratrace oxytetracycline with SERS technique.

In this paper, a new Pd metal organic framework (PdMOF) surface molecularly imprinted polyaniline nanocatalytic probe (PdMOF@MIP) with dual functions of recognition and catalysis was synthesized. It is found that the PdMOF@MIP nanoprobe can not only identify OTC but also catalyze the new nanoreaction of NaH2PO2-HAuCl4 to generate gold nanoparticles (AuNPs), and the generated AuNPs could be traced by surface-enhanced Raman scattering (SERS). When OTC specifically binds to PdMOF@MIP to generate PdMOF@MIP-OTC conjugate, its catalytic effect is weakened and the analytical signal is reduced linaerly. Accordingly, a new, highly sensitive, selective and simple SERS/RRS/Abs trimode detection platform for OTC was constructed. The linear range of SERS was 0.0625 ng/mL âˆ¼ 1.75 ng/mL and the limit of detection was 0.015 ng/mL. This new nanocatalytic probe detection strategy can also be used for the selective detection of other antibiotics such as tetracycline and doxycycline, respectively. In addition, the nanocatalytic mechanism has been investigated.

In situ synthesis of oxygen-doped carbon quantum dots embedded in MIL-53(Fe) for efficient degradation of oxytetracycline.

Introducing carbon quantum dots (CQDs) into photocatalysts is believed to boost the charge transfer rate and reduce charge complexation. Doping heteroatoms such as N, S, or P enable CQDs to have an uplifting electron transfer capability. However, the application of oxygen-doped CQDs to improve the performance of photocatalysts has rarely been reported. Herein, a type of carbon-oxygen quantum dots (COQDs) was in situ embedded into MIL-53(Fe) to aid peroxydisulfate (PDS)-activated degradation of oxytetracycline (OTC) under visible light irradiation. The successful embedding of COQDs was confirmed by XRD, FT-IR, XPS, SEM, and TEM techniques. Photoelectrochemical testing confirmed its better performance. The prepared COQDs1/MIL-53(Fe) showed 88.2% decomposition efficiency of OTC in 60 min, which was 1.45 times higher than that of pure MIL-53(Fe). In addition, the performance of the material was tested at different pH, OTC concentrations, catalyst dosing, and PDS dosing. It was also subjected to cyclic testing to check stability. Moreover, free radical trapping experiments and electron paramagnetic resonance were conducted to explore the possible OTC deterioration mechanism. Our work provides a new idea for the development of MOFs for water treatment and remediation.

Tetracyclines contamination in European aquatic environments: A comprehensive review of occurrence, fate, and removal techniques.

Tetracyclines are among the most commonly used antibiotics for the treatment of bacterial infections and the improvement of agricultural growth and feed efficiency. All compounds in the group of tetracyclines (tetracycline, chlorotetracycline, doxycycline, and oxytetracycline) are excreted in an unchanged form in urine at a rate of more than 70%. They enter the aquatic environment in altered and unaltered forms which affect aquatic micro- and macroorganisms. This study reviews the occurrence, fate, and removal techniques of tetracycline contamination in Europe. The average level of tetracycline contamination in water ranged from 0 to 20 ng/L. However, data regarding environmental contamination by tetracyclines are still insufficient. Despite the constant presence and impact of tetracyclines in the environment, there are no legal restrictions regarding the discharge of tetracyclines into the aquatic environment. To address these challenges, various removal techniques, including advanced oxidation, adsorption, and UV treatment, are being critically evaluated and compared. The summarized data contributes to a better understanding of the current state of Europe's waters and provides insight into potential strategies for future environmental management and policy development. Further research on the pollution and effects of tetracyclines in aquatic environments is therefore required.

Plant and microbial response in constructed wetland treating tetracycline antibiotic polluted water: Evaluating the effects of microplastic size and concentration.

Microplastics (MPs) and antibiotics are novel water pollutants that have attracted increasing attention. Constructed wetlands (CWs) are widely applied treating various types of polluted water. How these two new pollutants affect plants and microorganisms in CWs, especially deciphering the unknown roles of MPs size and concentration, is of great essential. Here, five CW treatments with submerged macrophyte Myriophyllum aquaticum were established to treat oxytetracycline (OTC) antibiotic-polluted water. The effects of polystyrene (PS) nanoplastics (NPs) (700 nm) and MPs (90-110 µm) on plant and microbial communities at 10 µg/L and 1 mg/L, respectively, were systematically evaluated. PS reduced the nitrogen and phosphorus removal efficiencies and inhibited OTC removal. Low doses (10 µg/L) of NPs and high doses (1 mg/L) of MPs had the greatest effects on plant and microbial responses. The overall effect of MPs was greater than that of NPs. Compared with high NPs concentration (1 mg/L), low concentrations (10 µg/L) had higher catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) content. However, the activity and content of MPs at low concentrations (10 µg/L) were lower than those at high concentrations (1 mg/L). The coexistence of OTC and MPs/NPs decreased the microbial diversity and abundance. Low doses of NPs and high doses of MPs decreased the relative abundance of Abditibacteriota, Deinococccota, and Zixibacteria. Redundancy and network analyses revealed a strong correlation between pollutant removal and plant and microbial responses. NH4+-N and OTC removal was positively and negatively correlated with CAT, SOD, and MDA content, respectively. MDA positively correlated to chlorophyll content, whereas SOD showed a negative correlation with Chloroflexi. This study highlighted the scale effect of MPs in wastewater treatment via CWs. It enhances our understanding of the response of plants and microorganisms to the remediation of water co-polluted with MPs and antibiotics.

Enhanced photodegradation of oxytetracycline antibiotic in wastewater by implementing ZnO-loaded carbon fiber.

The antibiotic oxytetracycline (OCA) exhibits high insolubility in the natural environment, posing a significant challenge for its removal. This study synthesized a porous structure and a high-surface-area carbon fiber, incorporating zinc oxide (ZnO/CFB) for the effective removal of OCA in wastewater. The material characterization revealed exceptional optical and photochemical properties of ZnO/CFB, featuring a reduced band gap energy of 2.7 eV. ZnO/CFB exhibited robust performance in the photodegradation of OCA in wastewater, achieving an impressive removal efficiency of 86.7%. Remarkably, the reduction of total organic carbon (TOC) reached an outstanding 97.5%. LC-MS analysis confirmed the complete oxidation of OCA and its intermediates, transforming them into inorganic substances within 60 min. This study introduces an efficient strategy for eliminating antibiotic pollutants from wastewater, highlighting the potential of ZnO/CFB as an effective and stable photocatalyst for environmental remediation.