A review on the alternatives to antibiotics and the treatment of antibiotic pollution: Current development and future prospects

Oxygen vacancy-mediated BiVO4/Bi3O4Br S-scheme heterojunction for enhanced photocatalytic degradation of antibiotics

Overuse of antibiotics has triggered severe water pollution issues. A novel S-scheme heterojunction nanocomposite, BiVO4/Bi3O4Br, was designed and successfully synthesized in this work, which exhibits superior performance in degrading fluoroquinolone antibiotics (gatifloxacin hydrochloride (GAT) and lomefloxacin hydrochloride (LOM)) and tetracycline antibiotics (tetracycline hydrochloride (TCH)). The construction of the S-scheme heterojunction structure and the incorporation of oxygen vacancies (OVs), which furnish vital channels at the interfaces for the efficient migration of photogenerated carriers, are primarily responsible for the enhanced photocatalytic efficiency of BiVO4/Bi3O4Br. Furthermore, the possible degradation routes of GAT were thoroughly explored, and the photocatalytic degradation mechanism of BiVO4/Bi3O4Br was comprehensively elucidated. This study highlights the combined action of S-scheme heterojunctions and OVs in boosting photocatalytic performance, thus providing a fresh perspective for developing OVs-rich S-scheme heterojunction photocatalysts for wastewater treatment.

A "Turn-on" fluorescence sensing strategy based on DNA-templated silver nanoclusters for the detection of antibiotic resistance genes

BACKGROUND

Antibiotic resistance genes (ARGs) are emerging environmental contaminants that pose serious threats to human health and ecological security due to their rapid migration and transformation in the environment. Thus, developing a sensitive and rapid method to detect ARGs is significant.

RESULTS

In this study, the neighborhood-dependent fluorescent sensor was established with DNA templated silver nanoclusters (AgNCs) and multi-branched linear structure to detect the typical macrolide resistance gene ermB. A DNA fluorescent probe with a specific recognition fragment for AgNCs and a tuning enhancement sequence were designed. The probe and the target resistance genes were complementary hybridized to form a linear multi-branch DNA structure of bright yellow silver nanocluster beacon that realized fluorescence signal amplification and transduction.

SIGNIFICANCE

This method has the advantages of being enzyme-free, label-free and amplification-free for being applied to the rapid detection of specific ARGs and successfully detected macrolide resistance gene ermB with the LOD as low as 0.37 nM in environmental samples with complex composition.

Antibiotics shape the core microbial community distribution between floc and biofilm in an endogenous partial denitrification system: Insight from metabolic pathway

The response mechanism of microorganisms in partial denitrification (PD) system under antibiotic stress, particularly microbial energy metabolism and electron transfer, remain inadequately understood. This knowledge gap hinders the establishment of ecological links between microbial dynamics and macro-level reactor performance. To address this, moving bed biofilm reactors were employed to investigate the dynamic changes of microbial community and metabolism under sulfadiazine (SDZ) and ciprofloxacin (CIP) stress. Results showed that dosing 2 mg/L SDZ or CIP accelerated nitrite accumulation, achieving this milestone 15 days earlier than in the control group. At the end of the operational phase, nitrate removal efficiencies reached 90.3 ± 18.3 % (Control), 83.5 ± 16.2 % (SDZ-treated) and 93.9 ± 12.4 % (CIP-treated), with nitrate-to nitrite-transformation rates of 61.3 ± 12.7 %, 65.6 ± 13.1 % and 58.0 ± 21.2 %, respectively. The abundances of energy supply related genes, i.e., sucC and PK were higher in the CIP-treated group, while those in the other two groups were similar. The promoted tricarboxylic acid cycle and glycolysis led to NADH and ATP accumulation, accelerating nitrogen metabolism and benefiting early nitrite accumulation in the antibiotic-stressed system. More importantly, increasing antibiotics concentration from 2 mg/L to 4 mg/L induced selective migration of Thauera from floc to biofilm (abundance in floc reduced to < 2.01 %). Metagenomic sequencing indicated that the higher abundance of narGHI in biofilms, compared to flocs, was crucial for maintaining stable PD performance under antibiotic stress. The electron transport related genes, such as IDH1, DLD and DLAT, were more abundant in biofilms than in flocs after SDZ and CIP addition. These findings provide a theoretical basis for understanding the response mechanism of PD consortia to antibiotic.

Surface reconstruction of natural wood-derived, monolithic chainmail catalyst enables robust water purification

Chainmail catalysts, characterized by carbon layer-encapsulated active sites embedded within hierarchically porous carbon matrices, represent an optimal strategy for enhancing catalytic stability in the activation of peroxymonosulfate (PMS) for the degradation of organic pollutants. However, these powder catalysts face challenges such as agglomeration, sluggish diffusion kinetics, and difficulties in separation. In this study, we transformed low-cost natural wood into a monolithic, self-supported chainmail catalyst, Co@CW, by embedding Co nanoparticles within hierarchically porous carbonized wood. The Co@CW-800 chainmail catalyst effectively activated PMS through a dominant free radical pathway, achieving a high tetracycline (TC) removal efficiency of 94.5% within 30 minutes. Furthermore, Co@CW-800 exhibited good adaptability under various conditions and maintained its high degradation efficiency over multiple cycles due to the surface reconstruction effect. The chainmail catalyst Co@CW-800 activated PMS to degrade TC via three primary pathways and generated twelve intermediate products. Moreover, toxicity evaluations indicated a reduction in toxicity after TC degradation by the Co@CW-800/PMS system. This study presents an efficient, stable, and recyclable self-supported chainmail catalyst system, establishing a foundation for water pollution control and advancing environmentally friendly advanced oxidation technologies.

Subtleties of tetracycline removal during growth of microalgae-fungi consortia: Mechanistic insights from perspectives of extra- and intracellular metabolites

This study focused on tetracycline (TC) as the target antibiotic and utilized the emerging microbial system microalgae-fungi consortia to treat it. Results indicate that consortia composed of microalgae Chlorella sp. HL and fungi HW12 (Aspergillus caespitosus) (HL-HW12) exhibited the optimum TC removal (93.00 %, residual concentration: 2.73 mg/L) and biomass harvesting efficiency (92.69 %) among the five kinds of constructed microalgae-fungi consortia. Mechanism analysis indicated that outside the cell, microalgae-fungi consortia strengthened TC removal and biomass harvesting by augmenting the contents of proteins, polysaccharides, fulvic acids, and humic acids. While within the cell, microalgae-fungi consortia adjusted the abundance of critical metabolites in the amino acid metabolism, nucleotide metabolism, and other metabolic pathways to cope with the coercion of TC and facilitated its elimination. This study not only provides good TC microbial treatment systems but also comprehensively reveals the TC removal and metabolic response mechanisms by microalgae-fungi consortia.

Remediation of antibiotic pollution in the global environment by iron-based materials activating advanced oxidation processes: A systematic review

Antibiotic pollution and its associated resistance genes have emerged as a global environmental and health concern, with widespread detection in various environmental media such as water, soil, atmosphere, and sediment, as well as in organisms. Hence, it is imperative to develop effective remediation technologies for the targeted treatment of antibiotic pollution to mitigate its environmental and health risks. This paper reviews the status of antibiotic pollution in major countries, territories, and regions worldwide. Addressing the risks cause by antibiotics and their resistance genes and achieving efficient remediation of antibiotic pollutants. Additionally, the study explores the issue of antibiotic use and resistance in detail from a global perspective. It provides a critical scientific foundation for controlling global antibiotic resistance through multi-dimensional integrated analysis. In 2021, 4.71 million deaths globally were attributed to antibiotic resistance, with countries such as India and China being the most affected. It also examined the predominant types and sources of antibiotic pollutants, as well as key remediation technologies for addressing antibiotic contamination. Antibiotics such as amoxicillin and ciprofloxacin are commonly found in surface waters at concentrations ranging from 1 to 120 μg L-1. Furthermore, this paper highlighted the distinctive advantages of advanced oxidation processes (AOPs) in addressing antibiotic pollution, demonstrating removal efficiencies exceeding 90 % under optimal conditions. Our review underscored the pivotal role of iron-based materials and porous biochar in AOPs, showing promising results in various environmental settings. Future research should prioritize the development of multifunctional iron-based composites with improved catalytic stability, environmental compatibility, and recyclability. Moreover, expanding the field-scale application of these materials, particularly in low-resource or high-risk regions, will be essential to translate laboratory successes into global impact. This analysis is designed to inform and guide future initiatives to control and eliminate antibiotic contamination.

Porcine β-Defensin 2 Expressed in Pichia pastoris Alleviates Enterotoxigenic Escherichia coli-Induced Intestinal Injury and Inflammatory Response in Mice

Enterotoxigenic Escherichia coli (ETEC), a common intestinal pathogen, can colonize the intestines and induce diarrhea in piglets, which brings great economic losses to the swine industry. Antibiotics are recommended to the treatment for diarrhea caused by ETEC in weaned piglets. However, with the emergence and spread of multidrug-resistant ETEC, there is an urgent need to develop alternatives to antibiotics. Due to the unique antibacterial mechanism of targeting bacterial membranes, antimicrobial peptides (AMPs) are promising candidates. In this study, the activity of crude recombinant porcine β-defensin 2 (rPBD2) expressed in Pichia pastoris (P. pastoris) was measured in vitro. Mice infected with ETEC were orally administered 16, 8, and 4 AU crude rPBD2 for 7 consecutive days to evaluate its anti-infective activity in vivo. The results showed that in addition to broad antibacterial activity against Gram-positive and -negative bacteria, crude rPBD2 displayed high tolerance to temperatures ranging from 20 to 60 °C, a broad range of pH, trypsin, pepsin, and physiological concentrations of salts. In an ETEC-induced mouse model, the oral administration of crude rPBD2 decreased diarrhea scores and the intestinal/carcass ratio and alleviated body weight loss. Additionally, crude rPBD2 decreased bacterial loads in stools and the colon (HP group), and the levels of serum pro-inflammatory cytokines IL-6 (HP group) and TNF-α (HP and MP groups), and increased the villus height and the ratio of villus height to crypt depth (VH/CD) in the ileum (HP and MP groups). Our study provides a cost-effective way for PBD2 production and identifies it as a promising candidate to combat ETEC-induced infection.

Enhancing antibiotic removal in constructed wetlands: A MgFe-LDHs-based strategy for optimizing microbial communities and metabolic functions

To efficiently remove antibiotics from domestic and livestock wastewater in southern China, vertical flow constructed wetlands (CWs) were designed with and without magnesium-iron layered double hydroxides (MgFe-LDHs). Their removal efficiencies for three typical antibiotics (tetracycline, oxytetracycline, and ofloxacin) were evaluated. Results showed that MgFe-LDHs significantly improved nitrogen and phosphorus removal (18.7 %-25.6 %) and enhanced the degradation of tetracycline, oxytetracycline, and ofloxacin (13.1 %-17.8 %). High-resolution LC-MS analysis indicated significant biodegradation through various pathways, such as oxidation, hydrolysis, and dealkylation. Analysis of the Shannon diversity index demonstrated that the introduction of novel MgFe-LDHs enhanced microbial diversity and evenness at the phylum, class, and genus levels. The introduction of MgFe-LDHs increased microbial diversity and enriched antibiotic-degrading genera like Xanthobacter, Ochrobactrum, and Stenotrophomonas. Moreover, MgFe-LDHs may have enhanced the metabolic pathways of glycolysis and the tricarboxylic acid cycle, thereby improving the microbial degradation of organic matter. In summary, MgFe-LDHs exhibited a multifaceted role in enhancing antibiotic removal in CWs by inducing the enrichment of antibiotic-degrading bacteria and regulating the metabolic functions of the microbial community, while also ensuring higher nitrogen and phosphorus removal efficiency.

Growth, Carcass Traits, Blood Chemistry and Gut Microbiota in Broiler Chickens Fed Diets Enriched With Garden Cress Seed Powder as a Natural Growth Enhancer

This study investigated the effects of garden cress seed powder (GCSP) as a natural growth promoter and antioxidant agent in broiler diets, focusing on growth performance, carcass characteristics, microbial load and blood traits. A total of 210 1-day-old Arbor Acres broiler chicks were assigned to 3 experimental groups in a completely randomized design. Each group consisted of 7 replicates with 10 unsexed chicks per replicate. The dietary treatments included: (A) a basal diet without additives (control); (GCSP 1) a basal diet supplemented with 1 g GCSP/kg diet and (GCSP 2) a basal diet supplemented with 2 g GCSP/kg diet. The results revealed no significant differences in body weight (BW), BW gain (BWG), feed intake (FI) and feed conversion ratio (FCR) between the GCSP-treated groups and the control. However, numerically, the GCSP-supplemented groups exhibited improved BW, BWG and FCR compared to the control. Carcass traits remained largely unaffected, except for dressing percentage, carcass yield, thigh proportion and abdominal fat percentage, where significant differences were observed. Blood biochemical analysis showed a reduction in total protein, albumin and globulin levels in GCSP-fed groups, whereas high-density lipoprotein (HDL) levels increased and low-density lipoprotein (LDL) and very LDL (VLDL) levels decreased, though these changes were not statistically significant. Immunological and antioxidative responses improved, as evidenced by elevated immunoglobulin Y (IgY), immunoglobulin M (IgM) and superoxide dismutase (SOD) levels, alongside reduced malondialdehyde (MDA) levels in the GCSP-fed groups compared to the control. In conclusion, dietary supplementation with GCSP enhanced broiler immunity and antioxidative status, promoting increased IgY, IgM and SOD levels while reducing MDA levels. These findings highlight GCSP as a potential natural additive to improve broiler health and contribute to the production of healthier poultry products for consumers.

Highly antibacterial and biocompatible polylysine-modified silk fibroin for potential food preservation and biomedical applications

Bacterial infection remains a thorny problem in food, medicine, and other fields. Due to the emergence of antibiotic-resistant bacteria, it is critical to develop an effective strategy to yield novel antibacterial agents. Herein, a new type of non-antibiotic antimicrobial material was successfully synthesized by grafting ε-polylysine (EPL) onto silk fibroin (SF). The resulting ε-polylysine-modified silk fibroin (SF-EPL) possessed the possibility to be processed into different formats. As the EPL content increased, SF-EPL exhibited higher positive charge levels, similar to those of EPL. Notably, the incorporation of 10 % EPL endowed superior antibacterial effects against E. coli and S. aureus (>90 %), while maintaining excellent biocompatibility. Furthermore, SF-10%EPL effectively extended the shelf life of cherry tomatoes, significantly delaying weight loss and the decline in titratable acidity content. The obtained SF-EPL may represent a promising substitute for food preservation and biomedical applications.

Solutions to the Dilemma of Antibiotics Use in Livestock and Poultry Farming: Regulation Policy and Alternatives

While the application of antibiotics in livestock production has undeniably propelled the rapid growth of animal husbandry, the escalating crisis of antimicrobial resistance stemming from antibiotic use poses significant threats to global public health and sustainable agricultural development. To address this critical challenge, multifaceted strategies have been implemented through coordinated policy interventions and scientific innovations. This review systematically examines two pivotal dimensions: (1) evolving regulatory frameworks governing antibiotic usage and (2) emerging non-antibiotic alternatives, with a particular focus on their implementation mechanisms and technological maturation. The analysis of transnational antibiotic governance encompasses comparative policy evolution in the European Union, the United States, and China. These regulatory paradigms address critical control points including registration management policies, usage monitoring systems, and integrated surveillance programs. Concerning technological alternatives, six categories of antibiotic substitutes are critically evaluated: Chinese herbal formulations, plant-derived essential oils, antimicrobial peptides, microecological agents, acidifiers, and enzyme preparations. These solutions are functionally categorized into prophylactic agents (enhancing disease resilience) and zootechnical additives (optimizing feed efficiency). These antibiotic alternatives demonstrate certain efficacy in alleviating the challenges of antibiotic overuse, yet they still face multiple implementation barriers. Further investigations are warranted to establish standardized efficacy evaluation protocols and conduct technoeconomic feasibility assessments under commercial-scale production conditions. Ultimately, resolving the antibiotic dilemma requires synergistic collaboration between regulatory bodies, pharmaceutical innovators, and academic researchers. This work emphasizes the crucial interplay between evidence-based policymaking and technological advancement in shaping sustainable livestock production systems.

Effects of dietary supplementation with Laurus nobilis extract on growth performance, carcass features, blood lipid profile, immunity, antioxidative status, digestive enzymes, and gut microbial load in growing New Zealand white rabbits

This study evaluated the effects of supplementing the diet of growing New Zealand White (NZW) rabbits with Laurus nobilis extract (LNE) on their growth, immune function, digestive enzyme activity, and cecal microbiota. One hundred 5-week-old male New Zealand White rabbits were randomly assigned to five treatment groups (n = 20 per group) in a completely randomized design. The control group received a basal diet, while the other four groups received the basal diet supplemented with LNE at 1, 2, 3, and 4 g/kg, respectively. Results shown that higher LNE supplementation (3-4 g/kg) significantly improved growth parameters, including live body weight (LBW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR). Notably, with 4 g/kg LNE supplementation, there was a marked improvement in carcass characteristics, with reduced abdominal fat (P < 0.043) and increased percentages of dressing, carcass (P < 0.0051), and spleen (P < 0.0198). Furthermore, higher doses of LNE were associated with a reduction in lipid profiles, including decreases in total cholesterol (TC, P < 0.0004), triglycerides (TG, P < .0001), low-density lipoprotein (LDL, P < .0001), and very LDL (VLDL, P < .0001). Immune responses such as immunoglobulins M (IgM), G (IgG), A (IgA), and lysozyme were significantly improved in all LNE groups (P < 0.001). Antioxidant indicators, including superoxide dismutase (SOD, P < 0.0005), total antioxidant capacity (TAC, P < 0.0007), and glutathione peroxidase (GPX, P < .0001), were also enhanced by LEN dietary inclusion. In terms of gut health, pathogenic bacteria such as E-coli, Salmonella spp Coliform and were declined in all LEN supplementation (P < 0.01). Additionally, digestive enzymes including amylase, lipase and protease activities were enhanced by feeding LNE (2, 3 and 4g/kg diet, P < .0001). These findings suggest that LNE supplementation, particularly at 4 g/kg, enhances the growth, health, and metabolic efficiency of NZW rabbits, providing potential benefits for their overall grwoth and well-being.

Application of iron-modified biochar in the fields of adsorption and degradation of antibiotics

Antibiotics, as emerging contaminants, have led to persistent global pollution issues, prompting long-standing attention on methods for their effective removal. Among various methods, iron-modified biochar stood out for its ability to adsorb and degrade antibiotics in the environment because biochar can provide a porous structure and oxygen-rich functional groups for efficient antibiotic adsorption, while the Fe2+/Fe3+ redox cycle in the iron modification biochar enhanced electronic transmission and further increased degradation. This review systematically summarized preparation methods of different iron-modified biochar, the adsorption capacities, mechanisms, and influencing factors of pollutants. It also explored the co-activation of iron and biochar, which enhanced the release of free radicals through Fenton-like oxidation pathways and accelerated degradation through photocatalytic electron-hole pair production. Additionally, the relationship between adsorption and degradation was discussed. Notably, an environmental risk assessment of iron-modified biochar and disposal of the used iron-modified biochar were discussed, which were critical for practical applications. Finally, the review highlighted the future directions of antibiotic pollution control and the broader potential of iron-modified biochar.

Effect of antibiotics on diverse aquatic plants in aquatic ecosystems

The widespread presence of antibiotics in aquatic ecosystems, mainly due to their use in medicine and veterinary practices, poses a significant environmental challenge. Aquatic plants play a vital role in maintaining ecosystem stability, but their responses to antibiotics vary by species, influenced by differences in their traits and interactions with environmental factors. However, the specific ways antibiotics affect these plants remain poorly understood. In this study, we conducted a meta-analysis of 167 peer-reviewed studies to investigate the mechanisms of antibiotic uptake and their effects on different types of aquatic plants-submerged, emergent, and floating. Our analysis shows that antibiotics, particularly common ones like sulfonamides, tetracyclines, and quinolones, impact aquatic plants through multiple pathways. Submerged and floating plants often face widespread, direct exposure, resulting in "full-coverage" impacts, while emergent plants experience mixed exposure patterns, affecting both submerged and aerial parts and leading to "partial-coverage" impacts. These findings provide a foundation for phytoremediation strategies, enabling the rational selection and management of aquatic plant types to mitigate antibiotic pollution. Our study underscores the ecological risks posed by antibiotic contamination in aquatic ecosystems and offers a theoretical framework for developing effective restoration strategies.

Effect of Supplemental Essential Oils Blend on Broiler Meat Quality, Fatty Acid Profile, and Lipid Quality

This investigation evaluates the impact of the EOB on chicken growth performance, meat quality, and lipid metabolism. Two hundred and fifty-six one-day-old, white-feathered broilers were randomly allocated to four groups. Each group was subdivided into eight replicates, each with eight unsexed chicks, including the control group (CON), EOB150, EOB250, and EOB350, with 0, 150, 250, and 350 mg/L of the EOB added to the drinking water, respectively. The expression levels of genes associated with antioxidants and lipid metabolism were analyzed using real-time polymerase chain reaction (RT-PCR). Additionally, the FA profile of the breast muscle was determined using gas chromatography. The data displayed that those birds in the EOB250 group had a higher breast muscle index compared to the CON group. The breast meat in the EOB groups showed that there is increased yellowness, water holding capacity (WHC), and polyunsaturated fatty acids (PUFAs), while cooking losses, drip losses, and saturated fatty acids (SFAs) were reduced compared to the CON. The application of supplements for the EOB250 and EOB350 groups increased antioxidant indices as well as the expression of antioxidant-related genes in the liver and muscles. However, these groups decreased the concentrations of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL-C) in serum and liver compared to the EOB150 and CON groups. These EOB groups downregulated expression of some genes linked to liver FA synthesis and elevated the expressions of lipid β-oxidation-related genes compared to the CON. It can be concluded that the supplementation with 250 mg/L of the EOB has the potential as an alternative water additive in the broiler industry.

Microporous carbon derived from waste plastics for efficient adsorption of tetracycline: Adsorption mechanism and application potentials

In recent years, the accumulation of waste plastics and emergence plastic-derived pollutants such as microplastics have driven significantly the development and updating of waste plastic utilization technology. This study prepared the porous carbon (PC-1-KOH) material directly from polyethylene terephthalate (PET) in waste plastic bottles using KOH activation and molten salt strategy for efficient removal of antibiotic tetracycline (TC). The maximum removal efficiency of TC was 100.0% with a PC-1-KOH weight of 20 mg. In addition, the TC removal efficiency stayed over 80.0% within the rage of pH of 3-9 and different water bodies. The adsorption process was described by the Pseudo-second-order kinetic model and the Langmuir isotherm, suggesting that the adsorption of TC was predominantly chemical in nature and occurred on a homogeneous surface. The pores filling, hydrogen bonding, π-π stacking interactions and electrostatic interaction are the main mechanisms of TC adsorption. This work demonstrates a sustainable approach to converting plastic waste derived materials into functional materials for effective pollution removal and environmental remediation.

Visible light-driven copper vanadate/biochar nanocomposite for heterogeneous photocatalysis degradation of tetracycline: Performance, mechanism, and application of machine learning

Water pollution caused by antibiotics is considered a major and growing issue. To address this challenge, high-performance copper vanadate-based biochar (CuVO/BC) nanocomposite photocatalysts were prepared to develop an efficient visible light-driven photocatalytic system for the remediation of tetracycline (TC) contaminated water. The effects of photocatalyst mass, solution pH, pollutant concentration, and common anions on the TC degradation were investigated in detail. Analytical techniques indicated that the CuVO exhibited a nanobelt-like structure with a uniform distribution on the wrinkled biochar surface. The XRD spectrum confirmed that the as-prepared nanomaterial was composed of Cu3V2O7(OH)2·2H2O. Meanwhile, XPS analysis revealed that copper was present in two forms: monovalent and divalent, while vanadium remained pentavalent. The CuVO/BC exhibited excellent stability and high visible light photocatalytic activity towards TC degradation over a wide pH range. The presence of SO42-, H2PO4-, CO32-, and citric acid inhibited the degradation process due to the consuming of photogenerated h+ and •OH, while Cl- enhanced the efficiency of photocatalytic reactions due to generating chlorine oxidizing species. The CuVO/BC showed lower electron-hole recombination rate, more effective separation of photogenerated carriers, lower charge transfer resistance, and higher visible light absorption capacity comparing to pure CuVO by the addition of BC, thus improving the overall photocatalytic performance. In terms of oxidation mechanism, the EPR test and quenching experiment revealed that the contribution of the active species to the degradation of TC followed the order h+ > 1O2 > •OH > •O2-. Through the application of machine learning models to analyse the influencing factors of photocatalytic processes, it was discovered that the GBDT model exhibited optimal reliability for the photocatalytic system, and the simulation results were in agreement with the experimental findings.

Efficient simultaneous degradation of multiple sulfonamide antibiotics in soil using biocarbon-based nanomaterials as catalysts for persulfate activation

There is an urgent need to develop effective and sustainable methods to decrease sulfonamide (SA) contamination of soil. Herein, a non-homogeneous system of zero-valent metal-biochar-based composites was proposed and tested for persulfate (PS) activation. This system employed zero-valent iron (Fe0) as an electron donor to catalyze the cleavage of the OO bond in PS, thereby generating reactive oxygen species (ROS) that degrade SAs. Notably, the incorporation of elemental sulfur (S) significantly mitigated the passivation of Fe0, leading to an enhanced degradation capability of the system. The system decomposes 84-97 % of SAs at their concentration in soil suspension 10 mg/kg in 3 h. Among the coexistence of several SAs, the system showed the fastest degradation rate of sulfisoxazole with a kobs of 0.0305 min-1, nearing complete removal within 3 h. The system is resistant to the impact of organic matter in soil. It allows to decrease concentration of sulfadiazine in actual contaminated soil on 73 % in 2 h. The system remains effective with decreasing concentrations of PS from 20 mM to 2.5 mM, which lowered the operating cost. T.E.S.T software evaluation showed a significant reduction in the bioaccumulation toxicity and developmental toxicity of the degradation products, suggesting that the system is environmentally friendly. The high efficiency of the catalytic system, the simplicity and economy of the manufacturing process, the resistance to interference in real soil, and the environmental friendliness make this technology promising for mitigating the problem of the environment contamination by SAs.

From river to groundwater: Antibiotics pollution, resistance prevalence, and source tracking

The extensive use of antibiotics has led to their frequent detection as residues in the environment. However, monitoring of their levels in groundwater and the associated ecological and health risks remains limited, and the impact of river pollution on groundwater is still unclear. This study focused on the highly urbanized Maozhou River and its groundwater. Forty-five antibiotics and microbial community composition were analyzed by high-resolution LC-MS/MS and 16S rRNA gene sequencing, respectively. These endpoints were measured in sediment, surface- and groundwater sampled during wet and dry seasons, while isolation and resistance profiling of Escherichia coli was performed in groundwater. This study aimed to assess the ecological and health risks posed by antibiotics in the Maozhou River and its groundwater, to assess the prevalence and type of antimicrobial resistance in Escherichia coli, and to trace the sources of antibiotic resistance genes (ARGs) in groundwater. Multiple antibiotics detected in the river and sediment were predicted to pose high risks to algae growth and bacterial resistance selection. In groundwater, the antibiotics erythromycin and norfloxacin were predicted to pose a medium risk to algae and a low risk towards bacterial resistance. Furthermore, significant positive correlations were observed between several predominant bacterial phyla in the river and groundwater and the detected antibiotics, suggesting a possible effect of local antibiotic residues on bacterial community composition. Antimicrobial susceptibility testing of 76 Escherichia coli isolates revealed 74 % exhibited resistance to at least one tested antibiotic and 7.9 % exhibiting multidrug resistance, which was confirmed by ARG-targeted PCR analysis. SourceTracker analysis of ARGs in groundwater indicated that ARG contamination in shallow groundwater was primarily from river sediments, while contamination in deeper groundwater originated mainly from river water. The results emphasize the need to address river pollution, as it directly impacts groundwater quality, particularly in areas with severe antibiotic contamination.

Antibacterial carbon dots

Bacterial infections significantly threaten human health, leading to severe diseases and complications across multiple systems and organs. Antibiotics remain the primary treatment strategy for these infections. However, the growing resistance of bacteria to conventional antibiotics underscores the urgent need for safe and effective alternative treatments. In response, several approaches have been developed, including carbon dots (CDs), antimicrobial peptides, and antimicrobial polymers, all of which have proven effective in combating bacterial resistance. Among these, CDs stand out due to their unique advantages, including low preparation cost, stable physicochemical properties, high biocompatibility, tunable surface chemistry, strong photoluminescence, and efficient generation of reactive oxygen species. These features make CDs highly promising in antibacterial applications. This review explores the development of antibacterial CDs, focusing on their mechanisms of action-physical destroy, biochemical damage, and synergistic effects-while highlighting their potential for clinical use as antibacterial agents.

Degradation of levofloxacin by dielectric barrier discharge plasma/chlorine process: Roles of reactive species and control of chlorination disinfection byproducts

In this study, a novel process of dielectric barrier discharge (DBD)/chlorine for levofloxacin (LEV) degradation was investigated. The combined system boosted the degradation efficiency of LEV from 77.8% to 97.5%, improved the reaction rate constant by 2.3 times, and reduced energy consumption by 64.5%. DBD/chlorine process was highly efficient for LEV degradation across a pH range of 3.3-10.8, with removal rates varying from 90.3% to 97.5%. The electron paramagnetic resonance and scavenging experiments demonstrated the generation of reactive oxygen species (ROS, including HO•, 1O2, and O2•-) and reactive chlorine species (RCS) in the DBD/chlorine system, with 1O2 in the nonradical pathway being crucial for LEV removal. Crucially, effective activation of chlorine not only encouraged the production of reactive species but also prevented the formation of disinfection by-products (DBPs), successfully controlling the ecotoxicity of the reaction system. DBD could activate chlorine to form chlorate and HO•, which in turn triggered the production of RCS. The comparison of the LEV degradation pathway was proposed with or without chlorine in the DBD process. Finally, the effects of different water quality and water bodies demonstrated the application prospects of the DBD/chlorine process. This work provided an efficient technique for the elimination of antibiotics by non-thermal plasma/chlorine.

Enhancing broiler growth and carcass quality: impact of diets enriched with Moringa oleifera leaf powder conjugated with zinc nanoparticles

This study evaluated the effects of Moringa oleifera leaf powder extract stabilized with zinc nanoparticles (ZnNPs-MLPE) as a natural growth promoter in broiler diets. Randomly assigned 264 one-day-old Ross 308 chicks to four different feeding treatments, with each group being subdivided into six replicates, each comprising 11 unsexed chicks. The control group was fed a basic diet without additives, while the experimental groups were supplemented with 1.0, 2.0, or 3.0 cm³ of ZnNPs-MLPE/L of diet. The findings demonstrated that 2.0 and 3.0 cm³/L ZnNPs-MLPE supplementation significantly enhanced live body weight (LBW) and weight gain (BWG). Feed intake (FI) and feed conversion ratio (FCR) did not show significant differences between the treated groups and the control, indicating that the additive did not negatively affect feed efficiency. However, an increase in abdominal fat was noted in the ZnNPs-MLPE treatments relative to the control. Blood analysis revealed that the ZnNPs-MLPE groups had significantly lower levels of "total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and alanine transaminase (ALT) compared to the control group. In contrast, total protein (TP), albumin, and the albumin/globulin (A/G) ratio" were higher in the ZnNPs-MLPE groups. Immunoglobulins IgY and IgM, as well as superoxide dismutase (SOD) levels, were elevated. Malondialdehyde (MDA) levels were reduced, indicating improved antioxidant capacity and immune function in the ZnNPs-MLPE-treated groups. In conclusion, supplementation with ZnNPs-MLPE at 2.0 and 3.0 cm³/L positively impacted broiler growth efficiency, antioxidant capacity, and immunological functionality. These findings support the potential of ZnNPs-MLPE as an effective natural growth enhancer for producing healthier poultry products.

Antimicrobial Peptides from Porcine Blood Cruor Hydrolysates as a Promising Source of Antifungal Activity

Porcine blood, a significant byproduct of the pork industry, represents a potential source of antimicrobial peptides (AMPs). AMPs offer a promising alternative to chemical antimicrobials, which can be used as natural preservatives in the food industry. AMPs can exhibit both antibacterial and/or antifungal properties, thus improving food safety and addressing the growing concern of antibiotic and antifungal resistance. The objective of this study was to evaluate the antimicrobial activity of potential AMPs previously identified from porcine cruor hydrolysates. To this end, a total of sixteen peptides were chemically synthesized and their antimicrobial activities (antibacterial, anti-mold, and anti-yeast) were evaluated using microtitration and agar well diffusion methods against a wide range of microorganisms. Five new peptide sequences demonstrated antifungal activity, with Pep5 (FQKVVAGVANALAHKYH), an alpha-helix peptide, exhibiting the most promising results. Pep5 demonstrated efficacy against nine of the eleven fungal isolates, exhibiting low minimum inhibitory concentrations (MICs) and a fungicidal effect against key spoilage fungi (Rhodotorula mucilaginosa, Debaryomyces hansenii, Candida guilliermondii, Paecilomyces spp., Eurotium rubrum, Mucor racemosus, Aspergillus versicolor, Penicillium commune, and P. chrysogenum). These findings illustrate the potential of porcine blood hydrolysates as a source of AMPs, particularly antifungal peptides, which are less known and less studied than the antibacterial ones. Among the tested sequences, Pep5 exhibited the most promising characteristics, including broad-spectrum activity, low MICs, and a fungicidal effect. It is, therefore, a promising candidate for further research and for potential applications in the porcine industry and beyond.

Bioconversion of sulfamethazine-contaminated chicken manure by black soldier fly larvae: Effects on antibiotic resistance genes and microbial communities

Sulfamethazine (SM2), a widely detected antibiotic in livestock manure, poses environmental and health risks due to its persistence and the proliferation of antibiotic resistance genes (ARGs). In this study, we investigated the degradation of SM2 and the elimination of sulfonamide ARGs (sul1 and sul2) in chicken manure contaminated with varying concentration of SM2 by black soldier fly larvae (BSFL). Quantitative PCR and 16S rRNA gene sequencing were employed to monitor changes in sulfa ARGs and microbial community composition within both the larvae gut and chicken manure. During the 12-day test period, BSFL exhibited strong tolerance to SM2, significantly reducing SM2 concentrations by 80.54%-92.22% across different treatment groups. Concurrently, the abundance of sul1 and sul2 decreased by 79.27% and 79.92% in chicken manure, respectively. Additionally, microbial genera such as Firmicutes (47.18-65%) and Bacillus (9.32-10.25%), which were enriched in both the BSFL gut and chicken manure, were identified as potential contributors to SM2 degradation. These findings provide a promising biotechnological strategy for mitigating antibiotic contamination in livestock manure.

Impacts of dietary different levels of thyme leave powder as a natural growth promoter on growth performance, carcass characteristics, and blood indices of broilers

The objective of the present study was to ascertain the influence of thyme leaf powder (TLP) on growth rate, carcass features, and blood indicators in broiler diets as a natural antioxidant and antibiotic substitute. A fully randomized design experiment divided 264-day-old broiler chicks (Ross 308) into 4 experimental groups. Six replicates of each group, each containing 11 unsexed chicks, were created. The following were the therapies: control group without additive (basal diet); TLP1, TLP2 and TLP3: basal diet + 1, 2 and 3 g thyme leaves powder/kg diet, respectively. Results showed that TLP added at 2 or 3 g/kg of feed significantly enhanced body weight gain (except for the period from 16 to 30 d of life), feed intake (except for the period from 1 to 15 d of life), and feed conversion ratio throughout study period. Furthermore, there was a significant decrease in creatinine and alanine aminotransferase (ALT) with different TLP levels, particularly at a 3 g TLP/kg diet. Compared with the control group, the birds' 2 g TLP/kg diet included the highest levels of albumin and total protein and A/G (albumin/globulin) ratio. Furthermore, the birds fed 1 g TLP/kg feed had the lowest concentrations of low-density lipoprotein (LDL) and total cholesterol (TC). Moreover, chicks fed all treatment diets containing TLP had higher IgY concentrations than the control group. Nevertheless, the group that was fed a diet including 2 g TLP/kg had the highest IgM levels. Additionally, the superoxide dismutase activity (SOD) levels were highest in the birds fed a 1g TLP/kg diet and minimum in the birds fed the control diet. Notably, malondialdehyde (MDA) levels were maximum in birds fed a control meal and lowest in birds with a diet containing 1 g of TLP/kg. We may conclude that using TLP in broiler diets increases the birds' immunity, productivity, and overall health, especially at level 2 g of TLP/kg diet.

Mechanisms underlying the low-temperature adaptation of 17β-estradiol-degrading bacterial strain Rhodococcus sp. RCBS9: insights from physiological and transcriptomic analyses

The 17β-estradiol (E2)-degrading bacterium Rhodococcus sp.RCBS9 previously showed remarkable resistance to the combined stresses of low temperature and E2. In this study, physiological experiments and transcriptomic analysis were performed to investigate the mechanisms underlying the strain's low-temperature adaptation and briefly analyze how it maintains its ability to degrade E2 at low temperature. The results showed that the strain's signal transduction functions, adaptive changes in cell membrane and cell wall structure, gene repair functions, and synthesis of antioxidants and compatible solutes are key to its ability to adapt to low temperature. In addition, its stress proteins in response to low temperature were not typical cold shock proteins, but rather universal stress proteins (USPs) and heat shock proteins (HSPs), among others. The strain also upregulated biofilm production, transporter proteins for carbon source uptake, and proteins for fatty acid degradation to ensure energy generation. The strain's multiple stress responses work synergistically to resist low-temperature stress, ensuring its adaptability to low-temperature environments and ability to degrade E2. Finally, six genes related to survival at low temperature (identified in the transcriptome analysis) were expressed in E. coli BL21, and they were found to contribute to recombinant E. coli growth at low temperature.

Ecological criteria for antibiotics in aquatic environments based on species sensitivity distribution

Due to the substantial production and use of antibiotics, they inevitably remain in aquatic environments, posing a serious threat to aquatic ecosystems. However, there are currently no criteria of antibiotics for ecological risk in the water environment. In the present study, three types of antibiotics (tetracyclines, sulfonamides and quinolones) that are often detected in water environments were investigated. Toxicity data regarding bacteria, algae, plants, invertebrates and vertebrates were selected, and the species sensitivity distribution was used to obtain the ecological risk criteria of antibiotics to aquatic organisms. Animals are the least sensitive to antibiotics. The overall toxicity of antibiotics is most sensitive to bacteria and cyanobacteria, followed by green algae and plants. The recommended ecological criteria for tetracyclines, quinolones, and sulfonamides are 22, 17, and 94 μg/L, respectively. Ofloxacin needs to be used with caution because it has a small acute predicted no-effect concentration (PNEC) of 0.6 μg/L. The ecological risk criterion for chronic toxicity of total antibiotics was determined to be 1.4 μg/L. The PNECs measured for the quinolone, tetracycline, and sulfonamide antibiotics were 0.5, 2.2, and 2.4 μg/L, respectively. Norfloxacin had the highest chronic toxicity zone of 353, indicating that chronic poisoning is most likely to occur. Moreover, there was an exponential correlation between acute PNEC and chronic PNEC. In addition, a quantitative structure-activity relationship model was constructed for acute ecological risk criteria of antibiotics to aquatic organisms. These findings can expand the ecological risk threshold data on the effects of antibiotics on aquatic organisms, and provide a theoretical basis for the environmental risk assessment of antibiotics.

Occurrence and distribution of emerging contaminants in wastewater treatment plants: A globally review over the past two decades

Emerging contaminants are pervasive in aquatic environments globally, encompassing pharmaceuticals, personal care products, steroid hormones, phenols, biocides, disinfectants and various other compounds. Concentrations of these contaminants are detected ranging from ng/L to μg/L. Even at trace levels, these contaminants can pose significant risks to ecosystems and human health. This article systematically summarises and categorizes data on the concentrations of 54 common emerging contaminants found in the influent and effluent of wastewater treatment plants across various geographical regions: North America, Europe, Oceania, Africa, and Asia. It reviews the occurrence and distribution of these contaminants, providing spatial and causal analyses based on data from these regions. Notably, the maximum concentrations of the pollutants observed vary significantly across different regions. The data from Africa, in particular, show more frequent detection of pharmaceutical maxima in wastewater treatment plants.

Sales of Veterinary Antibiotics in Serbia: Identification of Problem Areas Using Standardized Metrics

One Health, as a multi-disciplinary approach, considers animal, human, and environmental health. Serbia continuously records high rates of antimicrobial resistance, with a knowledge gap on practices regarding veterinary antibiotic use, as no standardized data regarding veterinary consumption of antibiotics that would allow for temporal or spatial comparison are available in Serbia. This study aimed to describe the sales of veterinary antibiotics in Serbia. Aggregated wholesale data on veterinary drug sales were retrieved from the annual reports available from the Medicines and Medical Devices Agency of the Republic of Serbia for a period between 2017 and 2020. Veterinary use was analyzed using standard European Medicines Agency proposed methodology and expressed in milligrams of active substance per population correction unit (mg/PCU). Overall, there has been a 13% increase in aggregated sales, in mg/PCU, of antibiotic veterinary medicinal products (VMPs) for food-producing animals in Serbia between 2017 and 2020. With sales of around 110 mg/PCU in 2020, Serbia would have ranked ninth in Europe. In 2020, the overall highest-selling antibiotic classes were penicillins (27.62 mg/PCU), tetracyclines (27.54 mg/PCU), and aminoglycosides (12.8 mg/PCU), accounting for 61.9% of the total sales of antibiotic VMPs for food-producing animals, in mg/PCU. An increase in the use of macrolides and lincosamides and a decrease in the use of penicillins and the group classified as "other antibacterials" was noted. The current study identified an increase in the sales of veterinary antibiotics in Serbia and pointed out several potential problem areas.

Sulfonate-Bonded Conjugated Microporous Polymer Hollowed-Out Spheres to Capture Fluoroquinolone Antibiotics and Cationic Dyes from Wastewater

Developing adsorbent materials for the efficient removal of multiple organic pollutants in water is of importance technological significance. In the present work, a kind of conjugated microporous polymer (CMP) with a hollow sphere structure was constructed by applying SiO2 nanoparticles as a template and 1,3,5-triethynylbenzene (TEB) and 2,7-dibromocarbazole (27-DBCZ) as building blocks via the Sonogashira-Hagihara cross-coupling reaction. In order to further improve the dispersibility of the as-resulting CMPs in water, hydrophilic CMPs (H-S-CMPs) were obtained by a sulfonation modification. The adsorption performance of H-S-CMPs on dyes and antibiotics was investigated, which was based on different experimental parameters such as the initial concentration, contact time, temperature, pH, and adsorbent dose. The adsorption isotherm, kinetics, and thermodynamics were also studied, and the possible adsorption mechanism of H-S-CMPs was discussed. The experimental results illustrated that the adsorption process of H-S-CMPs on dyes and antibiotics is more consistent with the Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum adsorption capacities of H-S-CMPs for rhodamine B (RhB), methylene blue (MB), ciprofloxacin, and norfloxacin were 206.2, 324.7, 222.2, and 216.9 mg/g, respectively, which were determined according to the Langmuir isothern model. In addition, the adsorption mechanism of H-S-CMPs may be attributed to the synergistic effects of hydrogen bonding, electrostatic attraction, π-π stacking, and pore filling. After 5 cycles, H-S-CMPs still maintained good stability, and their removal rate of dyes could reach more than 70%. Notably, this polymeric hollow microsphere has been less extensively investigated as an adsorbent for the removal of dyes and antibiotics. As a result, based on the designable flexibility of CMPs and the unique structure of hollow microspheres, the material holds great promise for wastewater treatment in the presence of multiple pollutants.

Understanding the role of microbes in health and disease of farmed aquatic organisms

Aquaculture is critical to reduce protein deficiencies and supplement the world's demand for seafood. However, the culture environment predisposes farmed animals to infectious diseases. In particular, the high density of fish, crustacean, mollusk, sea cucumber or algal species allows for the rapid spread of infectious diseases resulting in devastating losses. Massive amounts of antibiotics have been used to sustain aquaculture production. This has led to the critical need to evaluate the impact of current control measures and optimize disease management schemes with an emphasis on global impact and sustainability. Furthermore, local and global changes have enhanced the pathogens' effects over aquaculture settings because increased temperature and pollution may trigger virulence genes and toxin production. Technological developments including biofloc technology, integrated multitrophic systems, recirculating aquaculture systems and probiotics have contributed to enhancing aquaculture sustainability and reducing the need for high loads of antibiotics and other chemicals. Furthermore, biotechnological tools (e.g., omics and cell biology) have shed light on cellular processes in the health and disease of reared organisms. Metagenomics is a reliable and relatively quick tool to identify microbial communities in aquaculture settings.

Silver Nanoparticles in Therapeutics and Beyond: A Review of Mechanism Insights and Applications

Silver nanoparticles (NPs) have become highly promising agents in the field of biomedical science, offering wide therapeutic potential due to their unique physicochemical properties. The unique characteristics of silver NPs, such as their higher surface-area-to-volume ratio, make them ideal for a variety of biological applications. They are easily processed thanks to their large surface area, strong surface plasmon resonance (SPR), stable nature, and multifunctionality. With an emphasis on the mechanisms of action, efficacy, and prospective advantages of silver NPs, this review attempts to give a thorough overview of the numerous biological applications of these particles. The utilization of silver NPs in diagnostics, such as bioimaging and biosensing, as well as their functions in therapeutic interventions such as antimicrobial therapies, cancer therapy, diabetes treatment, bone repair, and wound healing, are investigated. The underlying processes by which silver NPs exercise their effects, such as oxidative stress induction, apoptosis, and microbial cell membrane rupture, are explored. Furthermore, toxicological concerns and regulatory issues are discussed, as well as the present difficulties and restrictions related to the application of silver NPs in medicine.

Rapid Quantification of Oxytetracycline Based on Fluorescence Enhancement Influenced by pH

Accurate quantification of antibiotics in environmental samples is typically challenging due to the low antibiotic concentrations and the complexity of environmental matrices. This paper presents a fluorescence spectrometry method for determining oxytetracycline under alkaline conditions. The ionic distribution of the oxytetracycline solution was analyzed based on its dissociation constant. The dimethylamino group plays a crucial role in this method, as it promotes intramolecular charge transfer in the electronic excited state through its electron-donating capability with a lone electron pair. The presented method is straightforward, cost-effective, and holds potential for analyzing oxytetracycline in water sample after further investigation.

Screening of Neutralizing Antibodies against FaeG Protein of Enterotoxigenic Escherichia coli

The misuse of antibiotics in veterinary medicine presents significant challenges, highlighting the need for alternative therapeutic approaches such as antibody drugs. Therefore, it is necessary to explore the application of antibody drugs in veterinary settings to reduce economic losses and health risks. This study focused on targeting the F4ac subtype of the FaeG protein, a key adhesion factor in enterotoxigenic Escherichia coli (ETEC) infections in piglets. By utilizing formaldehyde-inactivated ETEC and a soluble recombinant FaeG (rFaeG) protein, an antibody library against the FaeG protein was established. The integration of fluorescence-activated cell sorting (FACS) and a eukaryotic expression vector containing murine IgG Fc fragments facilitated the screening of anti-rFaeG IgG monoclonal antibodies (mAbs). The results demonstrate that the variable regions of the screened antibodies could inhibit K88-type ETEC adhesion to IPEC-J2 cells. Furthermore, in vivo neutralization assays in mice showed a significant increase in survival rates and a reduction in intestinal inflammation. This research underscores the potential of antibody-based interventions in veterinary medicine, emphasizing the importance of further exploration in this field to address antibiotic resistance and improve animal health outcomes.

Antibacterial effect of the metal nanocomposite on Escherichia coli

Ag nanocomposites (NAs) have been found to induce irreversible harm to pathogenic bacteria, however, NAs tend to aggregate easily when used alone. These nanocomposites also show increased toxicity and their underlying antibacterial mechanism is still unknown. In short, practical applications of NA materials face the following obstacles: elucidating the mechanism of antibacterial action, reducing cytotoxicity to body cells, and enhancing antibacterial activity. This study synthesized a core-shell structured ZnFe2O4 @Cu-ZIF-8 @Ag (FUA) nanocomposite with high antibacterial activity and low cytotoxicity. The nanocomposites achieved a 99.99 % antibacterial rate against Escherichia coli (E. coli) and tetracycline-resistant E. coli (T - E. coli), in under 20 min at 100 μg/mL. The nanocomposites were able to inactivate E. coli due to the gradual release of Cu2+, Zn2+, and Ag+ ions, which synergistically form •OH from FUA in an aerobic environment. The presence of •OH has significant effects on the antibacterial activity. The released metal ions combine with •OH to cause damage to the bacterial cell wall, resulting in the leakage of electrolytes and ions. Moreover, in comparison to NA, the toxicity of FUA is considerably reduced. This study is expected to inspire the development of other silver-based nanocomposite materials for the inactivation of drug-resistant bacteria.

Formulating InVO4/α-Fe2O3 Heterojunction Composites for Photocatalytic Tetracycline Hydrochloride Degradation

This study reports the synthesis of InVO4/α-Fe2O3 heterojunction photocatalysts with different stoichiometric ratios via a two-step hydrothermal synthesis reaction. The prepared photocatalysts were characterized by XRD, SEM, TEM, XPS, and other methods. The prepared composites exhibited good photocatalysis of tetracycline hydrochloride. Among the InVO4/α-Fe2O3 heterojunction photocatalysts with different ratios, the InVO4/0.25α-Fe2O3 photocatalyst showed the highest degradation rate for 20 mg L-1 tetracycline hydrochloride. After three photocatalytic runs, it still exhibited excellent stability and reusability. Meanwhile, this study also found that superoxide radical anion (-O2-), electron (e-), hydroxyl radical (·OH), and photogenerated hole (h+) are the basic active substances in the photocatalytic process.

Effects of adding different levels of fructooligosaccharide to diet on productive performance, egg quality traits, immune response and blood metabolites in commercial laying hens

BACKGROUND

A prebiotic is defined as an indigestible feed substance that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the large intestine, thereby improving host health and products.

OBJECTIVES

This study was conducted to determine the effects of supplementing prebiotic fructooligosaccharide (FOS) to the diets of Hy-Line W-36 laying hens.

METHODS

A total of 168 Hy-Line W-36 laying hens were allocated to four dietary levels of FOS (0, 1.0, 2.0, 3.0 g/kg diet), 6 replicates of 7 birds each during 63-74. The experiment was performed using a completely randomized design.

RESULTS

Productive performance was not significantly affected by the FOS supplementation. Body weight gain was linearly decreased with increasing FOS levels in the diet (p < 0.01). However, eggshell strength, shell thickness and Ca and p percentages were not significantly affected, as were anti-sheep red blood cell titres, blood parameters and blood metabolites. In the first period of the experiment (63-65 weeks), shape index and Haugh unit at the dose of 3.0 g/kg FOS were significantly increased and decreased in comparison with control, respectively (p < 0.05). In the third and fourth periods (69-71 and 72-74 weeks of age), the FOS had no significant effect on the internal egg quality traits. Furthermore, FOS had a linear decrease in the most saturated fatty acids (SFAs), including myristic, palmitic, margaric and stearic fatty acids; some of the mono-un-SFA (MUFA; palmitoleic and ginkgolic acids), and poly-unsaturated fatty acids (γ-linolenic and eicosatrienoic).

CONCLUSIONS

Supplementing different levels of FOS to the diet of commercial laying hens had no significant effect on the layers' performance, immune response and blood parameters, whereas there was a significant effect on some of the internal egg quality traits and egg yolk fatty acid contents.

Hormesis in the Assessment of Toxicity Assessment by Luminescent Bacterial Methods

The threat posed by water pollutants to aquatic ecosystems and human health cannot be overlooked, and the assessment of the toxicity of these contaminants is paramount to understanding their risks and formulating effective control measures. Luminescent bacteria-based assays, as a vital tool in evaluating contaminant toxicity, encounter a challenge in ensuring accuracy due to the phenomenon of "Hormesis" exhibited by pollutants towards biological entities, which may skew toxicity assessments. This study elucidated the specific effects of pollutants on luminescent bacteria at different concentrations, used modeling to characterize the effects and predict their toxicity trends, and explored the applicable concentration ranges for different pollutants. Research revealed that six typical pollutants, namely PAHs, endocrine disruptors, antibiotics, pesticides, heavy metals, and phytosensory substances, could promote the luminescence intensity of luminescent bacteria at low concentrations, and the promotional effect increased and then decreased. However, when the concentration of the substances reached a certain threshold, the effect changed from promotional to inhibitory, and the rate of inhibition was directly proportional to the concentration. The EC50 values of six types of substances to luminescent bacteria is as follows: endocrine disruptors > pesticides > antibiotics > heavy metals > polycyclic aromatic hydrocarbons > chemosensory agents. The effect curves were further fitted using the model to analyze the maximum point of the promotion of luminescence intensity by different substances, the threshold concentration, and the tolerance of luminescent bacteria to different substances. The maximum promotion of bacterial luminescence intensity was 29% for Bisphenol A at 0.005 mg/L and the minimum threshold concentration of chromium was 0.004 mg/L, and the maximum bacterial tolerance to erythromycin is 6.74. In addition, most of the current environmental concentrations had a positive effect on luminescent bacteria and may still be in the range of concentrations that promote luminescence as the substances continue to accumulate. These findings will enhance the accuracy and comprehensiveness of toxicity assessments, thereby facilitating more informed and effective decision-making in the realms of environmental protection and pollution management.

Unraveling the effects and mechanisms of antibiotics on aerobic simultaneous nitrogen and phosphorus removal by Acinetobacter indicus CZH-5

The effects of antibiotics, such as tetracycline, sulfamethoxazole, and ciprofloxacin, on functional microorganisms are of significant concern in wastewater treatment. This study observed that Acinetobacter indicus CZH-5 has a limited capacity to remove nitrogen and phosphorus using antibiotics (5 mg/L) as the sole carbon source. When sodium acetate was supplied (carbon/nitrogen ratio = 7), the average removal efficiencies of ammonia-N, total nitrogen, and orthophosphate-P increased to 52.46 %, 51.95 %, and 92.43 %, respectively. The average removal efficiencies of antibiotics were 84.85 % for tetracycline, 39.32 % for sulfamethoxazole, 18.85 % for ciprofloxacin, and 23.24 % for their mixtures. Increasing the carbon/nitrogen ratio to 20 further improved the average removal efficiencies to 72.61 % for total nitrogen and 97.62 % for orthophosphate-P (5 mg/L antibiotics). Additionally, the growth rate and pollutant removal by CZH-5 were unaffected by the presence of 0.1-1 mg/L antibiotics. Transcriptomic analysis revealed that the promoted translation of aceE, aarA, and gltA genes provided ATP and proton -motive forces. The nitrogen metabolism and polyphosphate genes were also affected. The expression of acetate kinase, dehydrogenase, flavin mononucleotide enzymes, and cytochrome P450 contributed to antibiotic degradation. Intermediate metabolites were investigated to determine the reaction pathways.

Construction of a Wood Nanofiber-Bismuth Halide Photocatalyst and Catalytic Degradation Performance of Tetracycline from Aqueous Solutions

Nanostructured bismuth oxide bromide (BiOBr) has attracted considerable attention as a visible light catalyst. However, its photocatalytic degradation efficiency is limited by its low specific surface area. In this study, a solvothermal approach was employed to synthesize BiOBr, which was subsequently loaded onto cellulose nanofibers (CNFs) to obtain a bismuth halide composite catalyst. The performance of this catalyst in the removal of refractory organic pollutants such as tetracycline (TC) from solutions under visible light excitation was examined. Our results indicate that BiOBr/CNF effectively removes TC from the solution under light conditions. At a catalyst dosage of 100 mg/L, the removal efficiency for TC (with an initial concentration of 100 mg/L) was 94.2%. This study elucidates the relationship between the microstructure of BiOBr/CNF composite catalysts and their improved photocatalytic activity, offering a new method for effectively removing pollutants from water.

Innovative Bi5O7I/MIL-101(Cr) Compounds: A Leap Forward in Photocatalytic Tetracycline Removal

In environmental chemistry, photocatalysts for eliminating organic contaminants in water have gained significant interest. Our study introduces a unique heterostructure combining MIL-101(Cr) and bismuth oxyiodide (Bi5O7I). We evaluated this nanostructure's efficiency in adsorbing and degrading tetracycline (TC) under visible light. The Bi5O7I@MIL-101(Cr) composite, with a surface area of 637 m2/g, prevents self-aggregation seen in its components, enhancing visible light absorption. Its photocatalytic efficiency surpassed Bi5O7I and MIL-101(Cr) by 33.4 and 9.2 times, respectively. Comprehensive analyses, including scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirmed the successful formation of the heterostructure with defined morphological characteristics. BET analysis demonstrated its high surface area, while X-ray diffraction (XRD) confirmed its crystallinity. Electron spin resonance (ESR) tests showed significant generation of reactive oxygen species (ROS) like h+ and·•O2- under light, crucial for TC degradation. The material maintained exceptional durability over five cycles. Density functional theory (DFT) simulations and empirical investigations revealed a type I heterojunction between Bi5O7I and MIL-101(Cr), facilitating efficient electron-hole pair separation. This study underscores the superior photocatalytic activity and stability of Bi5O7I@MIL-101(Cr), offering insights into designing innovative photocatalysts for water purification.

Cefixime removal via WO3/Co-ZIF nanocomposite using machine learning methods

In this research, an upgraded and environmentally friendly process involving WO3/Co-ZIF nanocomposite was used for the removal of Cefixime from the aqueous solutions. Intelligent decision-making was employed using various models including Support Vector Regression (SVR), Genetic Algorithm (GA), Artificial Neural Network (ANN), Simulation Optimization Language for Visualized Excel Results (SOLVER), and Response Surface Methodology (RSM). SVR, ANN, and RSM models were used for modeling and predicting results, while GA and SOLVER models were employed to achieve the optimal conditions for Cefixime degradation. The primary goal of applying different models was to achieve the best conditions with high accuracy in Cefixime degradation. Based on R analysis, the quadratic factorial model in RSM was selected as the best model, and the regression coefficients obtained from it were used to evaluate the performance of artificial intelligence models. According to the quadratic factorial model, interactions between pH and time, pH and catalyst amount, as well as reaction time and catalyst amount were identified as the most significant factors in predicting results. In a comparison between the different models based on Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Coefficient of Determination (R2 Score) indices, the SVR model was selected as the best model for the prediction of the results, with a higher R2 Score (0.98), and lower MAE (1.54) and RMSE (3.91) compared to the ANN model. Both ANN and SVR models identified pH as the most important parameter in the prediction of the results. According to the Genetic Algorithm, interactions between the initial concentration of Cefixime with reaction time, as well as between the initial concentration of Cefixime and catalyst amount, had the greatest impact on selecting the optimal values. Using the Genetic Algorithm and SOLVER models, the optimum values for the initial concentration of Cefixime, pH, time, and catalyst amount were determined to be (6.14 mg L-1, 3.13, 117.65 min, and 0.19 g L-1) and (5 mg L-1, 3, 120 min, and 0.19 g L-1), respectively. Given the presented results, this research can contribute significantly to advancements in intelligent decision-making and optimization of the pollutant removal processes from the environment.