Enrofloxacin and Roundup® interactive effects on the aquatic macrophyte Elodea canadensis physiology

Alien emergent aquatic plants develop better ciprofloxacin tolerance and metabolic capacity than one native submerged species

Antibiotic pollution and biological invasion pose significant risks to freshwater biodiversity and ecosystem health. However, few studies have compared the ecological adaptability and ciprofloxacin (CIPR) degradation potential between alien and native macrophytes. We examined growth, physiological response, and CIPR accumulation, translocation and metabolic abilities of two alien plants (Eichhornia crassipes and Myriophyllum aquaticum) and one native submerged species (Vallisneria natans) exposed to CIPR at 0, 1 and 10 mg/L. We found that E. crassipes and M. aquaticum's growth were unaffected by CIPR while V. natans was significantly hindered under the 10 mg/L treatment. CIPR significantly decreased the maximal quantum yield of PSII, actual quantum yield of PSII and relative electron transfer rate in E. crassipes and V. natans but didn't impact these photosynthetic characteristics in M. aquaticum. All the plants can accumulate, translocate and metabolize CIPR. M. aquaticum and E. crassipes in the 10 mg/L treatment group showed greater CIPR accumulation potential than V. natans indicated by higher CIPR contents in their roots. The oxidative cleavage of the piperazine ring acts as a key pathway for these aquatic plants to metabolize CIPR and the metabolites mainly distributed in plant roots. M. aquaticum and E. crassipes showed a higher production of CIPR metabolites compared to V. natans, with M. aquaticum exhibiting the strongest CIPR metabolic ability, as indicated by the most extensive structural breakdown of CIPR and the largest number of potential metabolic pathways. Taken together, alien species outperformed the native species in ecological adaptability, CIPR accumulation and metabolic capacity. These findings may shed light on the successful invasion mechanisms of alien aquatic species under antibiotic pressure and highlight the potential ecological impacts of alien species, particularly M. aquaticum. Additionally, the interaction of antibiotic contamination and invasion might further challenge the native submerged macrophytes and pose greater risks to freshwater ecosystems.

Green Solutions for Antibiotic Pollution: Assessing the Phytoremediation Potential of Aquatic Macrophytes in Wastewater Treatment Plants

We compared the ability of one emergent (Sagittaria montevidensis), two floating (Salvinia minima and Lemna gibba), and one heterophyllous species (Myriophyllum aquaticum) to simultaneously remove sulfamethoxazole, sulfadiazine, ciprofloxacin, enrofloxacin, norfloxacin, levofloxacin, oxytetracycline, tetracycline, doxycycline, azithromycin, amoxicillin, and meropenem from wastewater in a mesocosm-scale constructed wetland over 28 days. Antibiotic concentrations in plants and effluent were analyzed using an LC-MS/MS to assess the removal rates and phytoremediation capacities. M. aquaticum did not effectively mitigate contamination due to poor tolerance and survival in effluent conditions. S. minima and L. gibba demonstrated superior efficiency, reducing the antibiotic concentrations to undetectable levels within 14 days, while S. montevidensis achieved this result by day 28. Floating macrophytes emerge as the preferable choice for remediation of antibiotics compared to emergent and heterophyllous species. Antibiotics were detected in plant tissues at concentrations ranging from 0.32 to 29.32 ng g-1 fresh weight, highlighting macrophytes' ability to uptake and accumulate these contaminants. Conversely, non-planted systems exhibited a maximum removal rate of 65%, underscoring the persistence of these molecules in natural environments, even after the entire experimental period. Additionally, macrophytes improved effluent quality regardless of species by reducing total soluble solids and phosphate concentrations and mitigating ecotoxicological effects. This study underscores the potential of using macrophytes in wastewater treatment plants to enhance overall efficiency and prevent environmental contamination by antibiotics, thereby mitigating the harmful impact on biota and antibiotic resistance. Selecting appropriate plant species is crucial for successful phytoremediation in constructed wetlands, and actual implementation is essential to validate their effectiveness and practical applicability.

Insights into the molecular network underlying phytotoxicity and phytoaccumulation of ciprofloxacin

Ciprofloxacin (CIP) is frequently detected in agricultural soils and can be accumulated by crops, causing phytotoxicities and food safety concerns. However, the molecular basis of its phytotoxicity and phytoaccumulation is hardly known. Here, we analyzed physiological and molecular responses of choysum (Brassica parachinensis) to CIP stress by comparing low CIP accumulation variety (LAV) and high accumulation variety (HAV). Results showed that the LAV suffered more severe inhibition of growth and photosynthesis than the HAV, exhibiting a lower tolerance to CIP toxicity. Integrated transcriptome and proteome analyses suggested that more differentially expressed genes/proteins (DEGs/DEPs) involved in basic metabolic processes were downregulated to a larger extent in the LAV, explaining its lower CIP tolerance at molecular level. By contrast, more DEGs/DEPs involved in defense responses were upregulated to a larger extent in the HAV, showing the molecular basis of its stronger CIP tolerance. Further, a CIP phytotoxicity-responsive molecular network was constructed for the two varieties to better understand the molecular mechanisms underlying the variety-specific CIP tolerance and accumulation. The results present the first comprehensive molecular profile of plant response to CIP stress for molecular-assisted breeding to improve CIP tolerance and minimize CIP accumulation in crops.

Microbial-influenced pesticide removal co-occurs with antibiotic resistance gene variation in soil-earthworm-maize system

Within human-influenced landscapes, pesticides cooccur with a variety of antibiotic stressors. However, the relationship between pesticides removal process and antibiotic resistance gene variation are not well understood. This study explored pesticide (topramezone, TPZ) and antibiotic (polymyxin E, PME) co-contamination using liquid chromatography-tandem mass spectrometry (LC-MS/MS), bacterial-16 S rRNA sequencing and high-throughput quantitative polymerase chain reaction (HT-qPCR) in a soil-earthworm-maize system. After incubating soil for 28 days with TPZ and PME (10 mg kg-1 dry weight), earthworm weight-gain, mortality rates, and maize plant weight-gain only differed slightly, but height-gain significantly decreased. PME significantly increased TPZ-removal in the soil. Accumulation of TPZ in earthworm's tissues may pose potential risks in the food chain. Combined pollution altered the microbial community structure and increased the abundance of functional microorganisms involved in aromatic compound degradation. Furthermore, maize rhizosphere can raise resistance genes, however earthworms can reduce resistance genes. Co-contamination increased absolute abundance of mobile genetic elements (MGEs) in bulk-soil samples, antibiotic resistance genes (ARGs) in skin samples and number of ARGs in bulk-soil samples, while decreased absolute abundance of transposase gene in bulk-soil samples and number of ARGs in rhizosphere-soil samples. Potential hosts harbouring ARGs may be associated with the antagonistic effect during resistance and detoxification of TPZ and PMB co-occurrence. These findings provide insights into the mechanism underlining pesticide removal regarding occurrence of ARGs in maize agroecosystem.

The enrofloxacin pollution control from fish to environment

Enrofloxacin (ENR) is used to prevent and treat fish diseases widely. However, its pollution is increasing public concern on human health and aquatic ecosystem safety. This review aims to find its pollution mechanisms and control way. It is found: (1) The excessive ENR administration is the main source, the sediment ENR escaping from photolysis is the secondary ENR pollution source; (2) The ENR-rich fishes were benthic lipid-rich fishes which can simultaneously absorb administration ENR and sediment ENR, the ENR bioaccumulation is positively related to the fish habitats ENR level and fish lipids content; (3) The ENR t1/2 varies with fish age, body weight, feedstuff lipids and crude fiber level, temperature, salinity, administration mode and dose; Consequently, the first control way is to conduct the minimum inhibitory concentration ENR, combining herbal medicines with antibacterial and detoxification functions. The second way is to develop the enrichment and removal techniques for sediment ENR.

Removal of enrofloxacin using Eichhornia crassipes in microcosm wetlands

The global consumption of antibiotics leads to their possible occurrence in the environment. In this context, nature-based solutions (NBS) can be used to sustainably manage and restore natural and modified ecosystems. In this work, we studied the efficiency of the NBS free-water surface wetlands (FWSWs) using Eichhornia crassipes in microcosm for enrofloxacin removal. We also explored the behavior of enrofloxacin in the system, its accumulation and distribution in plant tissues, the detoxification mechanisms, and the possible effects on plant growth. Enrofloxacin was initially taken up by E. crassipes (first 100 h). Notably, it accumulated in the sediment at the end of the experimental time. Removal rates above 94% were obtained in systems with sediment and sediment + E. crassipes. In addition, enrofloxacin was found in leaves, petioles, and roots (8.8-23.6 µg, 11-78.3 µg, and 10.2-70.7 µg, respectively). Furthermore, enrofloxacin, the main degradation product (ciprofloxacin), and other degradation products were quantified in the tissues and chlorosis was observed on days 5 and 9. Finally, the degradation products of enrofloxacin were analyzed, and four possible metabolic pathways of enrofloxacin in E. crassipes were described.

Phytoremediation for antibiotics removal from aqueous solutions: A meta-analysis

Antibiotics are widely used as drugs and enter water bodies through various routes, leading to environmental pollution. As a green in-situ remediation technology, phytoremediation has been proven to be highly effective in removing antibiotics present in the aqueous phase. However, these data are distributed in various studies and lack systematic analysis, which could provide a more comprehensive understanding of the current status and trends in the research field. Based on this, a meta-analysis was conducted from three perspectives in this study: the factors influencing antibiotics removal by phytoremediation, the effect of antibiotics on plant physiological indexes, and the accumulation and translocation of antibiotics in plants. The results showed that plants have a significant effect on antibiotics removal, which is influenced by plant species, running time, biomass, antibiotic types and antibiotic concentration. Although some physiological indexes of plants changed under stress from high antibiotic concentrations, most plant species demonstrated resistance to antibiotic concentrations below 100 μgL-1. Additionally, the amount of antibiotics accumulated in plants was extremely little, so the risk of secondary pollution was minimal during phytoremediation. The results of this study reveal the main factors influencing antibiotics removal by phytoremediation and plant physiological responses to antibiotics, providing a reference for improving the rational application of phytoremediation for antibiotics removal. In addition, it will provide concepts and directions for improving the efficiency of sustainable and environmentally friendly remediation methods for treating antibiotic pollution.

Pharmaceutical-contaminated irrigation water: implications for ornamental plant production and phytoremediation using enrofloxacin-accumulating species

Enrofloxacin (Enro) has been widely encountered in natural water sources, and that water is often used for irrigation in crop production systems. Due to its phytotoxicity and accumulation in plant tissues, the presence of Enro in water used for crop irrigation may represent economical and toxicological concerns. Here, we irrigated two ornamental plant species (Zantedeschia rehmannii Engl. and Spathiphyllum wallisii Regel.) with water artificially contaminated with the antimicrobial enrofloxacin (Enro; 0, 5, 10, 100, and 1000 μg L-1) to evaluate its effects on ornamental plant production, as well as its accumulation and distribution among different plant organs (roots, leaves, bulbs, and flower stems), and examined the economic and environmental safety of commercializing plants produced under conditions of pharmaceutical contamination. The presence of Enro in irrigation water was not found to disrupt plant growth (biomass) or flower production. Both species accumulated Enro, with its internal concentrations distributed as the following: roots > leaves > bulbs > flower stems. In addition to plant tolerance, the content of Enro in plant organs indicated that both Z. rehmannii and S. wallisii could be safety produced under Enro-contaminated conditions and would not significantly contribute to contaminant transfer. The high capacity of those plants to accumulate Enro in their tissues, associated with their tolerance to it, indicates them for use in Enro-phytoremediation programs.

Antioxidant Enzyme and Cytochrome P450 Activities Are Involved in Horseweed (Conyza Sumatrensis) Resistance to Glyphosate

The intensive global use of glyphosate has led to the evolution of glyphosate resistant (GR) weed species, including the economically damaging horseweed (Conyza sumatrensis). We evaluated the glyphosate resistance mechanisms of C. sumatrensis. While 5-enolpyruvylshikimate-3-phosphate synthase activity was similar between the glyphosate resistant (GR) and nonresistant biotypes, plants from the GR population accumulated lower shikimate levels than susceptible ones, suggesting the absence of target-site resistance mechanisms. Decreases over time in glyphosate concentrations in GR leaves were not accompanied by increases in glyphosate concentrations in their stem and roots, indicating lower glyphosate distribution rates in GR plants. The early appearance of aminomethylphosphonic acid (the main glyphosate metabolite) in leaves, as well as its presence only in the stems and roots of GR plants, suggests faster glyphosate metabolism in GR plants than in susceptible ones. GR plants treated with glyphosate also showed greater antioxidant (ascorbate peroxidase [APX] and catalase [CAT]) and cytochrome P450-enzyme activities, indicating their great capacity to avoid glyphosate-induced oxidative stress. Three non-target mechanisms (reduced glyphosate translocation, increased metabolism, and increased antioxidant activity) therefore confer glyphosate resistance in C. sumatrensis plants. This is the first time that APX, CAT and P450-enzyme activities are related to GR in C. sumatrensis.

Heat waves rather than continuous warming exacerbate impacts of nutrient loading and herbicides on aquatic ecosystems

Submerged macrophytes are vital components in shallow aquatic ecosystems, but their abundances have declined globally. Shading by periphyton and phytoplankton/turbidity plays a major role in this decline, and the competing aquatic primary producers are subject to the complex influence of multiple stressors such as increasing temperatures, nutrient loading and herbicides. Their joint impact has rarely been tested and is difficult to predict due to potentially opposing effects on the different primary producers, their interactions and their grazers. Here, we used 48 mesocosms (2500 L) to simulate shallow lakes dominated by two typical submerged macrophytes, bottom-dwelling Vallisneria denseserrulata and canopy-forming Hydrilla verticillata, and associated food web components. We applied a combination of nutrient loading, continuous warming, heat waves and glyphosate-based herbicides to test how these stressors interactively impact the growth of submerged macrophytes, phytoplankton and periphyton as competing primary producers. Warming or heat waves alone did not affect phytoplankton and periphyton abundance, but negatively influenced the biomass of V. denseserrulata. Nutrient loading alone increased phytoplankton biomass and water turbidity and thus negatively affected submerged macrophyte biomass, particularly for V. denseserrulata, by shading. Glyphosate alone did not affect biomass of each primary producer under ambient temperatures. However, heat waves facilitated phytoplankton growth under combined nutrient loading and glyphosate treatments more than continuous warming. As a consequence, H. verticillata biomass was lowest under these conditions indicating the potential of multiple stressors for macrophyte decline. Our study demonstrated that multiple stressors interactively alter the biomass of primary producers and their interactions and can eventually lead to a loss of macrophyte communities and shift to phytoplankton dominance. These results show the risks in shallow lakes and ponds in agricultural landscapes and underline the need for multiple stressor studies as a base for their future management.

Effects of ciprofloxacin on Eichhornia crassipes phytoremediation performance and physiology under hydroponic conditions

Antibiotics can be absorbed by aquatic plants, but they seriously affect the health of aquatic plants and threaten the steady state of aquatic ecosystem. The phytoremediation performance and physiology of floating macrophyte (Eichhornia crassipes) under antibiotic ciprofloxacin (CIP) hydroponic conditions were investigated. It was found that CIP absorption of E. crassipes was up to 84.38% and the root was the main absorption tissue. Hydrolysis and microbial degradation were the second removal pathway of CIP followed the plant absorption. After 7 days of CIP exposure, the photosynthesis efficiency of E. crassipes remained stable, and the presence of CIP did not inhibit the growth of the plant. On the 14th day, the superoxide dismutase and catalase activities were increased in response to the CIP stress. However, the tender leaves of E. crassipes turned white and shrivel, attributed to a decrease in chlorophyll content and chlorophyll fluorescence parameters after 21 days of CIP exposure. These findings will have significant implications for E. crassipes to absorb CIP on a limited time-scale and provide a phytoremediation technology for antibiotics in water.

The Role of H2O2-Scavenging Enzymes (Ascorbate Peroxidase and Catalase) in the Tolerance of Lemna minor to Antibiotics: Implications for Phytoremediation

We investigated the individual and combined contributions of two distinct heme proteins namely, ascorbate peroxidase (APX) and catalase (CAT) on the tolerance of Lemna minor plants to antibiotics. For our investigation, we used specific inhibitors of these two H₂O₂-scavenging enzymes (p-aminophenol, 3-amino,1,2,4-triazole, and salicylic acid). APX activity was central for the tolerance of this aquatic plant to amoxicillin (AMX), whereas CAT activity was important for avoiding oxidative damage when exposed to ciprofloxacin (CIP). Both monitored enzymes had important roles in the tolerance of Lemna minor to erythromycin (ERY). The use of molecular kinetic approaches to detect and increase APX and/or CAT scavenging activities could enhance tolerance, and, therefore, improve the use of L. minor plants to reclaim antibiotics from water bodies.

Phytoremediation by ornamental plants: a beautiful and ecological alternative

Phytoremediation is an eco-friendly and economical technology in which plants are used for the removal of contaminants presents in the urban and rural environment. One of the challenges of the technique is the proper destination of the biomass of plants. In this context, the use of ornamental plants in areas under contamination treatment improves landscape, serving as a tourist option and source of income with high added value. In addition to their high stress tolerance, rapid growth, high biomass production, and good root development, ornamental species are not intended for animal and human food consumption, avoiding the introduction of contaminants into the food web in addition to improving the environments with aesthetic value. Furthermore, ornamental plants provide multiple ecosystem services, and promote human well-being, while contributing to the conservation of biodiversity. In this review, we summarized the main uses of ornamental plants in phytoremediation of contaminated soil, air, and water. We discuss the potential use of ornamental plants in constructed buffer strips aiming to mitigate the contamination of agricultural lands occurring in the vicinity of sources of contaminants. Moreover, we underlie the ecological and health benefits of the use of ornamental plants in urban and rural landscape projects. This study is expected to draw attention to a promising decontamination technology combined with the beautification of urban and rural areas as well as a possible alternative source of income and diversification in horticultural production.

Evaluating aquatic macrophytes for removing erythromycin from contaminated water: floating or submerged?

Water contamination by antibiotics is an emerging global problem, with impacts on both public health and the environment. Erythromycin has been encountered in bodies of water throughout the world, which demands the development of efficient remediation technologies. We investigated the physiological responses and phytoremediation capacity of four species of aquatic macrophytes, two floating (Salvinia molesta and Lemna minor) and two submerged (Myriophyllum aquaticum and Rotala rotundifolia). The plants were exposed to relevant environmental concentrations of erythromycin (0 and 1.7 µg l^-1) in artificially contaminated water for seven days. Physiological evaluations evidenced the ability of that antibiotic to promote oxidative events in those plants, such as the activation of antioxidant enzymes (ascorbate peroxidase and/or catalase). S. molesta exposed to erythromycin demonstrated accumulations of hydrogen peroxide and oxidative damage (lipid peroxidation) that was reflected in growth reductions. The erythromycin removal efficiency of floating plants varied from 9 to 12%, while submerged species varied from 31 to 44%. As such, submerged macrophyte species demonstrated the most efficient removal of erythromycin from contaminated waters, and are therefore more indicated for antibiotic phytoremediation projects.

Global transcriptome profiling reveals antagonizing response of head kidney of juvenile common carp exposed to glyphosate

Glyphosate (GLY) frequently detected in various water bodies has imposed a serious risk on fish. Head kidney of fish is an important defense organ, playing a vital part in antagonizing exogenous hazardous matter. The objective of this study was to characterize toxic mechanisms of GLY in head kidney of common carp based on transcriptome profiling. After 45-days exposure of GLY at environmentally relevant concentrations, juvenile common carp were used as experimental subjects to analyze how the head kidney responded to GLY. The transcriptome profiling identified 1381 different expressed genes (DEGs) between the control and exposure groups (5 and 50 mg/L). Functional analysis of DEGs substantiated over-representative pathways mainly involving cellular stress responses, cell proliferation and turnover, apoptosis, lipid metabolism, and innate immune processes in both treated groups compared with the control group. Predicted network of gene regulation indicated that GLY-induced tp53 played a vital role in linking a battery of signals. Furthermore, the expression of 10 candidate genes by qRT-PCR aligned with transcriptional profiling. In addition, western blotting analysis confirmed that GLY-induced apoptosis and cellular proliferation were closely involved in activating MAKP signaling pathway and lipid metabolism pathway in both treated groups. Collectively, these data demonstrate that head kidney of juvenile common carp mainly leverages upregulation of genes related to cell proliferation and turnover, apoptosis, and lipid metabolism to combat sub-chronic exposure of GLY. This study casts new understanding into the risk of GLY in aquatic animals.

Isolated and combined effects of glyphosate and its by-product aminomethylphosphonic acid on the physiology and water remediation capacity of Salvinia molesta

We evaluate the isolated and combined effects of glyphosate and its by-product aminomethylphosphonic acid (AMPA) and the potential of the aquatic macrophyte Salvinia molesta to remove these chemicals from contaminated water. Plants were exposed to environmentally relevant concentrations of glyphosate (0, 20, 40, 60, 80 and 100 µg l-1) or AMPA (0, 10, 20, 30, 40 and 50 µg l-1) for seven days. Then, based on the effective concentrations of glyphosate found to reduce photosynthetic rates by 10% (EC10) and 50% (EC50), the plants were exposed to combinations of 0, 16 and 63.5 µg glyphosate l-1 and 0, 5, 15, 25 µg AMPA l-1. The EC(10) and EC(50) were lower for AMPA (6.1 µg l-1 and 28.4 µg l-1 respectively) than for glyphosate (16 and 63.5 µg glyphosate l-1 respectively). When occurring together, the deleterious effects of those chemicals to plants increased. S. molesta plants removed up to 74.15% of glyphosate and 71.34% of AMPA from culture water. Due to its high removal efficiency, S. molesta can be used in phytoremediation programs. It will be important to evaluate the combined effects of glyphosate and AMPA in any toxicological studies of the herbicide.

Veterinary antibiotics and plant physiology: An overview

Antibiotics are considered one of the greatest advances of medicine and, in addition to their use in treating a wide spectrum of illnesses, they have been widely employed to promote animal growth. As many of those pharmaceuticals are only partially absorbed by the digestive system, a considerable fraction is excreted in its original active form or only partially metabolized. Therefore, the use of animal excrement in agriculture represents one of the principal routes of insertion of antibiotics into the environment. Within that context, plants, principally those of agricultural interest, will be exposed to those compounds when present in the soil or when irrigated with contaminated water. Although not yet fully understood, there are reports of phytotoxic effects of antibiotics that can diminish agricultural production. This review is designed to provide a general and integrative overview of physiological alterations observed in plants caused by environmental exposures to veterinary-use antibiotics. This text principally focuses on the processes involved in antibody absorption and accumulation, and their effects on the primary (photosynthesis, respiration, nitrogen assimilation) and oxidative metabolisms of plants. We also bring attention to germinative and plant establishment processes under conditions of antibiotic contamination. The different effects of different antibiotics on plant physiology are listed here to provide a better understanding of their phytotoxicities.

Crop irrigation (soybean, bean, and corn) with enrofloxacin-contaminated water leads to yield reductions and antibiotic accumulation

The increasing use of antibiotics in animal production has become an emergent environmental problem. The large percentages of applied antibiotic doses eliminated in animal excrement often end up contaminating water resources, which are then used for irrigation - compromising agricultural production and/or food security. Here, we evaluated the effects of crop irrigation with water artificially contaminated by enrofloxacin (10 μg l-1) and its accumulation in soybean, bean, and corn tissues. Grain production was evaluated on the basis of grain dry weight plant-1, while enrofloxacin and ciprofloxacin (its breakdown metabolite) concentrations in plant tissues were evaluated by HPLC after harvesting. Diminished production was observed only in soybean plants irrigated with antibiotic-contaminated water. Enrofloxacin [1.68 ng g fresh weight (FW)-1 to 26.17 µg g FW-1] and ciprofloxacin (8.23 ng g FW-1 to 51.05 ng g FW-1), were found in all of the plant tissues (roots, leaves, and seeds) of the three species. Regardless of the species, the highest enrofloxacin concentrations were observed in their roots, followed by the leaves and seeds, while ciprofloxacin concentrations varied among the different plant tissues of the different species. The presence of enrofloxacin in the water used for irrigating soybeans can result in productivity losses and, as that antibiotic was encountered in plant tissues (leaves and seeds) of all of the three species analyzed that are consumed in the diets of both humans and animals, it can interfere with food security.

Genotoxic effects of glyphosate on Physalaemus tadpoles

Genotoxicity studies have revealed that pesticides bind to genetic material in non-target vertebrates, thereby impairing the genetic integrity of these animals. The main objective of this study was to determine the genotoxic damage in erythrocytes of two native South American amphibian Physalaemus cuvieri and Physalaemus gracilis, both species exposed to a glyphosate-based herbicide. We evaluated the presence of micronuclei (MN) and erythrocyte nuclear abnormalities (ENA) as biomarkers for potential genotoxic compounds. Tadpoles were exposed to doses permitted by Brazilian legislation and concentrations found naturally in Brazilian and Argentinian waters (500, 700 and 1000 μg/L). Glyphosate-based herbicide caused micronuclei formation and several types of erythrocyte nuclear abnormalities in both Physalaemus species. The total frequency of MN and ENA demonstrated the occurrence of cell damage at all tested concentrations. Glyphosate herbicide can be considered a genotoxic that may impact the genetic integrity of native populations of P. cuvieri and P. gracilis.

Aquatic Macrophytes in Constructed Wetlands: A Fight against Water Pollution

There is growing concern among health institutions worldwide to supply clean water to their populations, especially to more vulnerable communities. Although sewage treatment systems can remove most contaminants, they are not efficient at removing certain substances that can be detected in significant quantities even after standard treatments. Considering the necessity of perfecting techniques that can remove waterborne contaminants, constructed wetland systems have emerged as an effective bioremediation solution for degrading and removing contaminants. In spite of their environmentally friendly appearance and efficiency in treating residual waters, one of the limiting factors to structure efficient artificial wetlands is the choice of plant species that can both tolerate and remove contaminants. For sometimes, the chosen plants composing a system were not shown to increase wetland performance and became a problem since the biomass produced must have appropriated destination. We provide here an overview of the use and role of aquatic macrophytes in constructed wetland systems. The ability of plants to remove metals, pharmaceutical products, pesticides, cyanotoxins and nanoparticles in constructed wetlands were compared with the removal efficiency of non-planted systems, aiming to evaluate the capacity of plants to increase the removal efficiency of the systems. Moreover, this review also focuses on the management and destination of the biomass produced through natural processes of water filtration. The use of macrophytes in constructed wetlands represents a promising technology, mainly due to their efficiency of removal and the cost advantages of their implantation. However, the choice of plant species composing constructed wetlands should not be only based on the plant removal capacity since the introduction of invasive species can become an ecological problem.

A review of the toxicity in fish exposed to antibiotics

Antibiotics are widely used in the treatment of human and veterinary diseases and are being used worldwide in the agriculture industry to promote livestock growth. However, a variety of antibiotics that are found in aquatic environments are toxic to aquatic organisms. Antibiotics are not completely removed by wastewater treatment plants and are therefore released into aquatic environments, which raises concern about the destruction of the ecosystem owing to their non-target effects. Since antibiotics are designed to be persistent and work steadily in the body, their chronic toxicity effects have been studied in aquatic microorganisms. However, research on the toxicity of antibiotics in fish at the top of the aquatic food chain is relatively poor. This paper summarizes the current understanding of the reported toxicity studies with antibiotics in fish, including zebrafish, to date. Four antibiotic types; quinolones, sulfonamides, tetracyclines, and macrolides, which are thought to be genetically toxic to fish have been reported to bioaccumulate in fish tissues, as well as in aquatic environments such as rivers and surface water. The adverse effects of these antibiotics are known to cause damage to developmental, cardiovascular, and metabolic systems, as well as in altering anti-oxidant and immune responses, in fish. Therefore, there are serious concerns about the toxicity of antibiotics in fish and further research and strategies are needed to prevent them in different regions of the world.

Individual and combined effects of amoxicillin, enrofloxacin, and oxytetracycline on Lemna minor physiology

We investigated individual and combined effects of environmentally representative concentrations of amoxicillin (AMX; 2 μg l^-1), enrofloxacin (ENR; 2 μg l^-1), and oxytetracycline (OXY; 1 μg l^-1) on the aquatic macrophyte Lemna minor. While the concentrations of AMX and ENR tested were not toxic, OXY decreased plant growth and cell division. OXY induced hydrogen peroxide (H₂O₂) accumulation and related oxidative stress through its interference with the activities of mitochondria electron transport chain enzymes, although those deleterious effects could be ameliorated by the presence of AMX and/or ENR, which prevented the overaccumulation of ROS by increasing catalase enzyme activity. L. minor plants accumulated significant quantities of AMX, ENR and OXY from the media, although competitive uptakes were observed when plants were submitted to binary or tertiary mixtures of those antibiotics. Our results therefore indicate L. minor as a candidate for phytoremediation of service waters contaminated by AMX, ENR, and/or OXY.

Emerging contaminants in water used for maize irrigation: Economic and food safety losses associated with ciprofloxacin and glyphosate

Chemicals used to assure agricultural production and the feasibility of planting sites often end up in bodies of water used for crop irrigation. In a pot study, we investigated the consequences associated with the irrigation of maize with water contaminated by ciprofloxacin (Cipro; 0, 0.2, 0.8, 1.4 and 2.0 μg l-1) and/or glyphosate (0, 5, 25 and 50 mg l-1) on yields and food safety. Glyphosate in concentrations ≥25 mg l-1 prevented plant establishment, regardless of Cipro presence. Evaluations made at the V5 stage of plants reveal that Cipro concentrations ≥0.8 μg l-1 and glyphosate decreased photosynthesis and induced changes in leaf anatomy and stem biophysical properties that may contribute to decreased kernel yields. When those chemicals were applied together, kernel yield reductions were accentuated, evidencing their interactive effects. Irrigation with contaminated water resulted in accumulations of Cipro and glyphosate (as well as its metabolite, aminomethylphosphonic acid) in plant tissues. Accumulation of these chemicals in plant tissues such as leaves and kernels is a problem, since they are used to feed animals and humans. Moreover, these chemicals are of potential toxicological concern, principally due to residue accumulations in the food chain. Specially, the antibiotic residue accumulations in maize tissues can assist the induction of antibiotic resistance in dangerous bacteria. Therefore, we point out the urgency of monitoring the quality of water used for crop irrigation to avoid economic and food-quality losses.

Can environmental concentrations of glyphosate affect survival and cause malformation in amphibians? Effects from a glyphosate-based herbicide on Physalaemus cuvieri and P. gracilis (Anura: Leptodactylidae)

Herbicides are the most common agrochemicals used in crops. Among them, glyphosate is the most widely applied in the world. Herbicides, especially organophosphates, have been shown to be hazardous to non-target species, including amphibians. The present study evaluated the acute and chronic effects of glyphosate-based herbicide (GBH), Roundup original® DI on tadpoles from two South American native species, Physalaemus cuvieri and P. gracilis. Spawnings were collected in the natural environment and maintained in the laboratory under controlled conditions. Acute and chronic toxicology trials began at stage 25 of Gosner (Herpetological 16:183-190, 1960). In an acute toxicity assay, seven GBH concentrations between 100 and 4500 μg a.e./L were tested over 96 h. For the chronic trials, tadpoles were subjected to both doses allowed by Brazilian legislation and to concentrations found in natural environment waters from Brazil and Argentina, between 65 and 1000 μg a.e/L over 14 days. Glyphosate had lethal effects on both studied species. Tadpoles showed shorter lengths and lower masses; that is, those that survived suffered chronic effects on growth and weight. The GBH maximum acceptable toxicant concentration for mortality and malformation was lower than the allowed level for Brazilian waters. The GBH tested in this study presented a high environmental and acute risk for the two studied species.