Performance evaluation of Trichoderma reseei in tolerance and biodegradation of diuron herbicide in agar plate, liquid culture and solid-state fermentation.

The present study evaluated the performance of the fungus Trichoderma reesei to tolerate and biodegrade the herbicide diuron in its agrochemical presentation in agar plates, liquid culture, and solid-state fermentation. The tolerance of T. reesei to diuron was characterized through a non-competitive inhibition model of the fungal radial growth on the PDA agar plate and growth in liquid culture with glucose and ammonium nitrate, showing a higher tolerance to diuron on the PDA agar plate (inhibition constant 98.63 mg L-1) than in liquid culture (inhibition constant 39.4 mg L-1). Diuron biodegradation by T. reesei was characterized through model inhibition by the substrate on agar plate and liquid culture. In liquid culture, the fungus biotransformed diuron into 3,4-dichloroaniline using the amide group from the diuron structure as a carbon and nitrogen source, yielding 0.154 mg of biomass per mg of diuron. A mixture of barley straw and agrolite was used as the support and substrate for solid-state fermentation. The diuron removal percentage in solid-state fermentation was fitted by non-multiple linear regression to a parabolic surface response model and reached the higher removal (97.26%) with a specific aeration rate of 1.0 vkgm and inoculum of 2.6 × 108 spores g-1. The diuron removal in solid-state fermentation by sorption on barley straw and agrolite was discarded compared to the removal magnitude of the biosorption and biodegradation mechanisms of Trichoderma reesei. The findings in this work about the tolerance and capability of Trichoderma reesei to remove diuron in liquid and solid culture media demonstrate the potential of the fungus to be implemented in bioremediation technologies of herbicide-polluted sites.

Three-state mathematical model for the assessment of DCMU-treated photosystem II heterogeneity.

Photosystem II (PSII) is one of the main pigment-protein complexes of photosynthesis which is highly sensitive to unfavorable environmental factors. The heterogeneity of PSII properties is essential for the resistance of autotrophic organisms to stress factors. Assessment of the PSII heterogeneity may be used in environmental monitoring for on-line detection of contamination of the environment. We propose an approach to assess PSII oxygen-evolving complex and light-harvesting antenna heterogeneity that is based on mathematical modeling of the shape of chlorophyll a fluorescence rise of 3-(3,4-dichlorophenyl)-1,1-dimethylurea-treated samples. The hierarchy of characteristic times of the processes considered in the model makes it possible to reduce the model to a system of three ordinary differential equations. The analytic solution of the reduced three-state model is expressed as a sum of two exponential functions, and it exactly reproduces the solution of the complete system within the time range from microseconds to hundreds of milliseconds. The combination of several such models for reaction centers with different properties made it possible to use it as an instrument to study PSII heterogeneity. PSII heterogeneity was studied for Chlamydomonas at different intensities of actinic light, for Scenedesmus under short-term heating, and for Chlorella grown in nitrate-enriched and nitrate-depleted media.

Biochemical and physiological alterations caused by Diuron and Triclosan in mussels (Mytilus galloprovincialis).

The rise in the utilization of pesticides within industrial and agricultural practices has been linked to the occurrence of these substances in aquatic environments. The objective of this work was to evaluate the uptake and adverse impacts of Diuron (Di) and Triclosan (TCS) on the mussel species Mytilus galloprovincialis. To accomplish this, the accumulation and toxicity of these pesticides were gauged following a brief period of exposure spanning 14 days, during which the mussels were subjected to two concentrations (50 and 100 µg/L) of each substance that are ecologically relevant. Chemical analysis of Di and TCS within gills and digestive gland showed that these pesticides could be accumulated in mussel's tissues. In addition, Di and TCS are preferably accumulated in digestive gland. Measured biomarkers included physiological parameters (filtration FC and respiration RC capacity), antioxidant enzyme activities (superoxide dismutase and catalase), oxidative damage indicator (Malondialdheyde concentration) and neurotoxicity level (acetylcholinesterase activity) were evaluated in gills and digestive glands. Both pesticides were capable of altering the physiology of this species by reducing the FC and RC in concentration and chemical dependent manner. Both pesticides induced also an oxidative imbalance causing oxidative stress. The high considered concentration exceeded the antioxidant defense capacity of the mussel and lead to membrane lipid peroxidation that resulted in cell damage. Finally, the two pesticides tested were capable of interacting with the neuromuscular barrier leading to neurotoxicity in mussel's tissues by inhibiting acetylcholinesterase. The ecotoxicological effect depended on the concentration and the chemical nature of the contaminant. Obtained results revealed also that the Di may exert toxic effects on M. galloprovincialis even at relatively low concentrations compared to TCS. In conclusion, this study presents innovative insights into the possible risks posed by Diuron (Di) and Triclosan (TCS) to the marine ecosystem. Moreover, it contributes essential data to the toxicological database necessary for developing proactive environmental protection measures.

Diuron-induced fetal Leydig cell dysfunction in in vitro organ cultured fetal testes.

Diuron is a phenylurea herbicide widely used in the agricultural industry. In recent years, the risk of infertility and developmental defects has increased due to exposure to environmental pollutants. In this study, we investigated the toxicity of diuron in fetal mouse testes using three-dimensional organ cultures. Fetal testes derived from embryonic day (E) 14.5 were cultured with 200 µM diuron for 5 days. The results revealed that diuron did not impair fetal germ cell proliferation or the expression levels of germ cell markers such as Ddx4, Dazl, Oct 4, Nanog, Plzf, and TRA 98. Similarly, the gene or protein expression of the Sertoli cell markers Sox9 and Wt1 in diuron-exposed fetal testes did not change after 5 days of culture. In contrast, diuron increased fetal Leydig cell markers (FLC), Cyp11a1, Cyp17a1, Thbs2, and Pdgf α, and decreased adult Leydig cell (ALC) markers, Sult1e1, Hsd173, Ptgds, and Vcam1. However, 3-ßHSD, an FLC and ALC marker, was consistently maintained upon exposure to diuron in fetal testes compared to non-treated groups. In conclusion, our study demonstrates that diuron negatively impacts Fetal Leydig cell development, although it does not affect germ and Sertoli cells.

Diuron and its metabolites induce mitochondrial dysfunction-mediated cytotoxicity in urothelial cells.

In the environment, or during mammalian metabolism, the diuron herbicide (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is transformed mainly into 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU) and 3,4-dichloroaniline (DCA). Previous research suggests that such substances are toxic to the urothelium of Wistar rats where, under specific exposure conditions, they may induce urothelial cell degeneration, necrosis, hyperplasia, and eventually tumors. However, the intimate mechanisms of action associated with such chemical toxicity are not fully understood. In this context, the purpose of the current in vitro study was to analyze the underlying mechanisms involved in the urothelial toxicity of those chemicals, addressing cell death and the possible role of mitochondrial dysfunction. Thus, human 1T1 urothelial cells were exposed to six different concentrations of diuron, DCA, and DCPMU, ranging from 0.5 to 500 µM. The results showed that tested chemicals induced oxidative stress and mitochondrial damage, cell cycle instability, and cell death, which were more expressive at the higher concentrations of the metabolites. These data corroborate previous studies from this laboratory and, collectively, suggest mitochondrial dysfunction as an initiating event triggering urothelial cell degeneration and death.

Assessing the spatiotemporal occurrence and ecological risk of antifouling biocides in a Brazilian estuary.

Diuron and Irgarol are common antifouling biocides used in paints to prevent the attachment and growth of fouling organisms on ship hulls and other submerged structures. Concerns about their toxicity to non-target aquatic organisms have led to various restrictions on their use in antifouling paints worldwide. Previous studies have shown the widespread presence of these substances in port areas along the Brazilian coast, with a concentration primarily in the southern part of the country. In this study, we conducted six sampling campaigns over the course of 1 year to assess the presence and associated risks of Diuron and Irgarol in water collected from areas under the influence of the Maranhão Port Complex in the Brazilian Northeast. Our results revealed the absence of Irgarol in the study area, irrespective of the sampling season and site. In contrast, the mean concentrations of Diuron varied between 2.0 ng L-1 and 34.1 ng L-1 and were detected at least once at each sampling site. We conducted a risk assessment of Diuron levels in this area using the risk quotient (RQ) method. Our findings indicated that Diuron levels at all sampling sites during at least one campaign yielded an RQ greater than 1, with a maximum of 22.7, classifying the risk as "high" based on the proposed risk classification. This study underscores the continued concern regarding the presence of antifouling biocides in significant ports and marinas in Brazilian ports, despite international bans.

Hormonal and haematological biomarkers as indicators of stress induced by Diuron herbicide toxicity on Clarias gariepinus (Burchell, 1822) sub-adults.

Diuron is a globally used herbicide for weed control but has anti-androgenic effects on androgens (testosterone and androstenedione), antagonist effects on thyroid hormone signaling, and haematological effects due to their biotransformation in fish. Endocrine-disrupting biomarkers such as thyroid hormones, sex hormones, and haematological indices of Clarias gariepinus sub-adults exposed to sub-lethal diuron concentrations were studied over a 28-day period. C. gariepinus (n = 200) sub-adults were exposed to sub-lethal concentrations (0.00, 0.09, 0.18, 0.26, and 0.35 mg/L) of diuron. Changes in the hormonal and haematological profiles of the exposed fish were concentration and exposure duration-dependent. The thyroxine (T4), tri-iodothyronine (T3), and 17ß-estradiol (E2) profiles decreased with an increase in concentration and exposure duration. The haemoglobin, pack cell volume, red blood cell, white blood cell, mean cell volume, and mean corpuscular haemoglobin cell decreased, while the mean corpuscular haemoglobin increased with an increase in concentration and exposure duration. Diuron induced stress and altered the physiological mechanisms of fish, and its application in farmlands should be regulated so as to enable a sustainable aquatic eco-system and fishery resources.

Growth and productivity of Haematococcus pluvialis and Coelastrella saipanensis by photosystem modulation for understanding the heterotrophic nutritional strategy for bioremediation application.

In this study, Haematococcus pluvialis and Coelastrella saipanensis were evaluated for heterotrophic nutrition potential in dairy waste medium by blocking the PSII using DCMU. The study was done by four sets of experiments. In the first set, in the different concentrations DCMU-treatments, 20µL showed pronounced effect in H. pluvialis and C. saipanensis as 89 % and 83% decrease in cells (>30 and > 250 cells/mL) compared to control (536 ± 12.35 × 104 and 1167 ± 15.35 × 104 cells/mL, respectively). Damage to the PS II by DCMU interrupted the growth, which in turn produced a significant drop in the number of cells. In the second round of experiment, growth of algae in various dairy waste concentrations suggest that dairy wastewater (DWW) provides enough nutrients to produce 35.71 % and 64.74 % more cells in H. pluvialis and C. saipanensis, respectively compared to the control. In the third set, high DCMU concentration was added to microalgae cultures in DWW to assess the heterotrophic nutrition potential. Growth in cell number 34.4 ± 19 and 617.46 ± 60.44 cells/mL was recorded in H. pluvialis and C. saipanensis when grown control medium whereas addition of DCMU reduced the cell number to 1.53 ± 0.75 and 55.13 ± 0.75 cells/mL on 15th day, respectively. This shows cells in cultures treated with DCMU reveal that algae can sustain their metabolic activity by utilizing the nutrients of dairy waste inhibiting photosystem. Fourth round of experiments found that microalgae could resume their growth and productivity by adapting to heterotrophic nutritional behaviour when DCMU given in mild dose at different time interval. This study conclude as C. saipanensis grows more readily by absorbing dairy waste nutrients than H. pluvialis. Therefore, C. saipanensis is an excellent choice for wastewater treatment through sustainable environmentally benign process after scale-up investigation. These results provide useful information to advance to molecular study for measuring microalgae's capability for bioremediation application.

Mechanistic insights into the effects of diuron exposure on Alexandrium pacificum.

Diuron (N-(3,4-dichlorophenyl)-N,N­dimethylurea, DCMU), a ureic herbicide, is extensively used in agriculture to boost crop productivity; however, its extensive application culminates in notable environmental pollution, especially in aquatic habitats. Therefore, the present study investigated the effect of diuron on the dinoflagellate Alexandrium pacificum, which is known to induce harmful algal blooms (HAB), and its potential to biodegrade DCMU. Following a four-day DCMU exposure, our results revealed that A. pacificum proficiently assimilated DCMU at concentrations of 0.05 mg/L and 0.1 mg/L in seawater, attaining a complete reduction (100 % efficiency) after 96 h for both concentrations. Moreover, evaluations of paralytic shellfish toxins content indicated that cells subjected to higher DCMU concentrations (0.1 mg/L) exhibited reductions of 73.4 %, 86.7 %, and 75 % in GTX1, GTX4, and NEO, respectively. Exposure to DCMU led to a notable decrease in A. pacificum's photosynthetic efficacy, accompanied by increased levels of reactive oxygen species (ROS) and suppressed cell growth, with a growth inhibition rate of 41.1 % at 72 h. Proteomic investigations pinpointed the diminished expression levels of specific proteins like SxtV and SxtW, linked to paralytic shellfish toxins (PSTs) synthesis, as well as key proteins associated with Photosystem II, namely PsbA, PsbD, PsbO, and PsbU. Conversely, proteins central to the cysteine biosynthesis pathways exhibited enhanced expression. In summary, our results preliminarily resolved the molecular mechanisms underlying the response of A. pacificum to DCMU and revealed that DCMU affected the synthesis of PSTs. Meanwhile, our data suggested that A. pacificum has great potential in scavenging DCMU.

Current Status of Antifouling Biocides Contamination in the Seto Inland Sea, Japan.

A monitoring survey of antifouling biocides was conducted in the Harima Nada Sea and Osaka Bay of the Seto Inland Sea, Japan to assess contamination by organotin (OT) compounds and alternative biocides. The concentrations of tributyltin (TBT) compounds in surface water ranged from 1.0 to 2.8 ng/L, and the detected TBT concentrations in the bottom water layer were higher than those in the surface water. The concentrations of TBT compounds in sediment samples ranged from 2.0 to 28 ng/g dry weight (dw), respectively. The concentrations of alternative biocides in the water and sediment were lower than those before the banning of TBT by the International Maritime Organization (IMO). Although triphenyltin (TPT) compounds were not detected in water samples, TPT compounds were detected in the range of < 0.1-2700 ng/g dw in sediment samples. Their concentrations in the water samples were as follows: diuron, < 1-53 ng/L; Sea-Nine 211, < 1-1.8 ng/L; Irgarol 1051, < 1-4.0 ng/L; dichlofluanid, < 1-343 ng/L; and chlorothalonil, < 1-1 ng/L, and the ranges of these alternative compounds in sediment samples were diuron, 32-488 ng/g dw; Sea-Nine 211, 47-591 ng/g dw; Irgarol, 33-128 ng/g dw; dichlofluanid, 67-8038 ng/g dw; and chlorothalonil, 31-2975 ng/g dw. Thus, the OTs and alternative biocides have still been detected in water and sediment samples from closed sea areas.

Application of biological early warning systems in wastewater treatment plants: Introducing a promising approach to monitor changing wastewater composition.

Wastewater treatment plants (WWTPs) are a major source of micropollutants to surface waters. Currently, their chemical or biological monitoring is realized by using grab or composite samples, which provides only snapshots of the current wastewater composition. Especially in WWTPs with industrial input, the wastewater composition can be highly variable and a continuous assessment would be advantageous, but very labor and cost intensive. A promising concept are automated real-time biological early warning systems (BEWS), where living organisms are constantly exposed to the water and an alarm is triggered if the organism's responses exceed a harmful threshold of acute toxicity. Currently, BEWS are established for drinking water and surface water but are seldom applied to monitor wastewater. This study demonstrates that a battery of BEWS using algae (Chlorella vulgaris in the Algae Toximeter, bbe Moldaenke), water flea (Daphnia magna in the DaphTox II, bbe Moldaenke) and gammarids (Gammarus pulex in the Sensaguard, REMONDIS Aqua) can be adapted for wastewater surveillance. For continuous low-maintenance operation, a back-washable membrane filtration system is indispensable for adequate preparation of treated wastewater. Only minor deviations in the reaction of the organisms towards treated and filtered wastewater compared to surface waters were detected. After spiking treated wastewater with two concentrations of the model compounds diuron, chlorpyrifos methyl, and sertraline, the organisms in the different BEWS showed clear responses depending on the respective compound, concentration and mode of action. Immediate effects on photosynthetic activity of algae were detected for diuron exposure, and strong behavioral changes in water flea and gammarids after exposure to chlorpyrifos methyl or sertraline were observed, which triggered automated alarms. Different types of data analysis were applied to extract more information out of the specific behavioral traits, than only provided by the vendors algorithms. To investigate, whether behavioral movement changes can be linked to impact other endpoints, the effects on feeding activity of G. pulex were evaluated and results indicated significant differences between the exposures. Overall, these findings provide an important basis indicating that BEWS have the potential to act as alarm systems for pollution events in the wastewater sector.

Electrochemical Determination of Hazardous Herbicide Diuron Using MWCNTs-CS@NGQDs Composite-Modified Glassy Carbon Electrodes.

Diuron (DU) abuse in weed removal and shipping pollution prevention always leads to pesticide residues and poses a risk to human health. In the current research, an innovative electrochemical sensor for DU detection was created using a glassy carbon electrode (GCE) that had been modified with chitosan-encapsulated multi-walled carbon nanotubes (MWCNTs-CS) combined with nitrogen-doped graphene quantum dots (NGQDs). The NGQDs were prepared by high-temperature pyrolysis, and the MWCNTs-CS@NGQDs composite was further prepared by ultrasonic assembly. TEM, UV-Vis, and zeta potential tests were performed to investigate the morphology and properties of MWCNTs-CS@NGQDs. CV and EIS measurements revealed that the assembly of MWCNTs and CS improved the electron transfer ability and effective active area of MWCNTs. Moreover, the introduction of NGQDs further enhanced the detection sensitivity of the designed sensor. The MWCNTs-CS@NGQDs/GCE electrochemical sensor exhibited a wide linear range (0.08~12 µg mL-1), a low limit of detection (0.04 µg mL-1), and high sensitivity (31.62 µA (µg mL-1)-1 cm-2) for DU detection. Furthermore, the sensor demonstrated good anti-interference performance, reproducibility, and stability. This approach has been effectively employed to determine DU in actual samples, with recovery ranges of 99.4~104% in river water and 90.0~94.6% in soil. The developed electrochemical sensor is a useful tool to detect DU, which is expected to provide a convenient and easy analytical technique for the determination of various bioactive species.

Remediation of pesticides contaminated water using biowastes-derived carbon rich biochar.

The competition impact and feedstock type on the removal of water pesticides using biochar have not yet been sufficiently investigated. Therefore, here we investigated the potentiality of three different biochars (BCs) derived from rice husk (RHB), date pit (DPB), and sugarcane bagasse (SBB) biowastes for the simultaneous removal of ten pesticides from water in a competitive adsorption system. The BCs structural characterization and morphology were investigated by XRD, FTIR spectroscopy and SEM analysis. The potential adsorption mechanisms have been investigated using various isothermal and kinetic models. RHB showed the highest removal percentages (61% for atrazine/dimethoate and 97.6% for diuron/chlorfenvinphos) followed by DPB (56% for atrazine/dimethoate and 95.4% for diuron/chlorpyrifos) and then SBB (60.8% for atrazine/dimethoate and 90.8% for chlorpyrifos/malathion). The higher adsorption capacity of RHB and DPB than SBB can be due to their high total pore volume and specific surface area (SSA). Langmuir model described well the sorption data (R2 = 0.99). Adsorption equilibrium was achieved after 60 min for RHB, and 120 min for both DPB and SBB. The optimum adsorbent dose (g/L) was 10 for RHB and 4 for DPB and SBB. The removal efficiency of pesticides was enhanced by decreasing pH from 9 to 5 by RHB and to 3 by DPB and SBB. XRD and FTIR spectroscopy confirmed that BCs contain some active adsorption groups and metal oxides such as MgO, SiO, Al2O3, CaO, and TiO2 that can play an effective role in the pesticides sorption. BET-N2 adsorption analysis demonstrated that the BC pore size contributes significantly to pesticide adsorption. These findings indicate that RHB, DPB, and SBB have ability for adsorption of water pesticides even under acidic conditions. Therefore, the rice husk, date pit, and sugarcane bagasse biowastes could be pyrolyzed and reused as effective and low-cost sorbents for elimination of hazardous substances such as pesticides in the aqueous environments.

Probing the Influence of Novel Organometallic Copper(II) Complexes on Spinach PSII Photochemistry Using OJIP Fluorescence Transient Measurements.

Modern agricultural cultivation relies heavily on genetically modified plants that survive after exposure to herbicides that kill weeds. Despite this biotechnology, there is a growing need for new sustainable, environmentally friendly, and biodegradable herbicides. We developed a novel [CuL2]Br2 complex (L = bis{4H-1,3,5-triazino[2,1-b]benzothiazole-2-amine,4-(2-imidazole) that is active on PSII by inhibiting photosynthetic oxygen evolution on the micromolar level. [CuL2]Br2 reduces the FV of PSII fluorescence. Artificial electron donors do not rescind the effect of [CuL2]Br2. The inhibitory mechanism of [CuL2]Br2 remains unclear. To explore this mechanism, we investigated the effect of [CuL2]Br2 in the presence/absence of the well-studied inhibitor DCMU on PSII-containing membranes by OJIP Chl fluorescence transient measurements. [CuL2]Br2 has two effects on Chl fluorescence transients: (1) a substantial decrease of the Chl fluorescence intensity throughout the entire kinetics, and (2) an auxiliary "diuron-like" effect. The initial decrease dominates and is observed both with and without DCMU. In contrast, the "diuron-like" effect is small and is observed only without DCMU. We propose that [CuL2]Br2 has two binding sites for PSII with different affinities. At the high-affinity site, [CuL2]Br2 produces effects similar to PSII reaction center inhibition, while at the low-affinity site, [CuL2]Br2 produces effects identical to those of DCMU. These results are compared with other PSII-specific classes of herbicides.

Contaminant occurrence, water quality criteria and tiered ecological risk assessment in water: A case study of antifouling biocides in the Qiantang River and its estuary, Eastern China.

Antifouling biocides may cause adverse effects on non-target species. This study aims to determine the distribution, sources, and ecological risks of antifouling biocides in the surface waters of the Qiantang River and its estuary in eastern China. The concentrations of total antifouling biocides were ranged from 12.9 to 215 ng/L for all water samples. Atrazine, diuron and tributyltin were the major compounds in the water bodies of the study area. The acute and chronic toxicity criteria for tributyltin, diuron and atrazine were derived for freshwater and saltwater, respectively, based on the species sensitivity distribution approach. The freshwater and saltwater criteria were slightly different, and the toxicity to aquatic organisms could be summarized as tributyltin > diuron > atrazine. The graded ecological risk rating showed that the long-term risk of TBT was significant in coastal waters. The pollution of TBT in the Qiantang River deserves further attention.

Tracking Targets of Dynamic Super-Enhancers in Vitro to Better Characterize Osteoclastogenesis and to Evaluate the Effect of Diuron on the Maturation of Human Bone Cells.

BACKGROUND: Osteoclasts are major actors in the maintenance of bone homeostasis. The full functional maturation of osteoclasts from monocyte lineage cells is essential for the degradation of old/damaged bone matrix. Diuron is one of the most frequently encountered herbicides, particularly in water sources. However, despite a reported delayed ossification in vivo, its impact on bone cells remains largely unknown. OBJECTIVES: The objectives of this study were to first better characterize osteoclastogenesis by identifying genes that drive the differentiation of CD14+ monocyte progenitors into osteoclasts and to evaluate the toxicity of diuron on osteoblastic and osteoclastic differentiation in vitro. METHODS: We performed chromatin immunoprecipitation (ChIP) against H3K27ac followed by ChIP-sequencing (ChIP-Seq) and RNA-sequencing (RNA-Seq) at different stages of differentiation of CD14+ monocytes into active osteoclasts. Differentially activated super-enhancers and their potential target genes were identified. Then to evaluate the toxicity of diuron on osteoblasts and osteoclasts, we performed RNA-Seq and functional tests during in vitro osteoblastic and osteoclastic differentiation by exposing cells to different concentrations of diuron. RESULTS: The combinatorial study of the epigenetic and transcriptional remodeling taking place during differentiation has revealed a very dynamic epigenetic profile that supports the expression of genes vital for osteoclast differentiation and function. In total, we identified 122 genes induced by dynamic super-enhancers at late days. Our data suggest that high concentration of diuron (50µM) affects viability of mesenchymal stem cells (MSCs) in vitro associated with a decrease of bone mineralization. At a lower concentration (1µM), an inhibitory effect was observed in vitro on the number of osteoclasts derived from CD14+ monocytes without affecting cell viability. Among the diuron-affected genes, our analysis suggests a significant enrichment of genes targeted by pro-differentiation super-enhancers, with an odds ratio of 5.12 (ρ=2.59×10-5). DISCUSSION: Exposure to high concentrations of diuron decreased the viability of MSCs and could therefore affect osteoblastic differentiation and bone mineralization. This pesticide also disrupted osteoclasts maturation by impairing the expression of cell-identity determining genes. Indeed, at sublethal concentrations, differences in the expression of these key genes were mild during the course of in vitro osteoclast differentiation. Taken together our results suggest that high exposure levels of diuron could have an effect on bone homeostasis. https://doi.org/10.1289/EHP11690.

Scavenging of copper(II) ions, phosphate(V) ions, and diuron from aqueous media by goethite modified with chitosan or poly(acrylic acid).

Goethite was modified by chitosan (CS) or poly(acrylic acid) (PAA) to improve its adsorptive abilities toward components of agrochemicals, i.e., copper ions (Cu), phosphate ions (P), and diuron. The pristine goethite effectively bound Cu (7.68 mg/g, 63.71%) and P (6.31 mg/g, 50.46%) only in their mixed systems. In the one adsorbate solutions, the adsorption levels accounted for 3.82 mg/g (30.57%) for Cu, 3.22 mg/g (25.74%) for P, and 0.15 mg/g (12.15%) for diuron. Goethite modification with CS or PAA did not yield spectacular results in adsorption. The maximum increase in adsorbed amount was noted for Cu ions (8.28%) after PAA modification as well as for P (6.02%) and diuron (24.04%) after CS modification. Both goethite modifications contributed to clear reduction in desorption of pollutants (even by 20.26% for Cu after PAA coating), which was mainly dictated by electrostatic attractive forces and hydrogen bonds formation occurring between macromolecules and impurities. The only exception in this phenomenon was Cu desorption from CS-modified solid-the polymer made it higher (to 95.00%). The Cu adsorption on PAA-modified goethite enhanced solid aggregation and thus facilitated metal cation separation from aqueous media. Consequently, the goethite modification with PAA was considered more promising for environmental remediation.

Photocatalytic degradation of organic micropollutants under UV-A and visible light irradiation by exfoliated g-C3N4 catalysts.

In the present study, the photocatalytic performance of exfoliated graphitic carbon nitride (g-C3N4) catalysts, with enhanced properties and response in UV and visible light irradiation, was evaluated for the removal of selected contaminants i.e., diuron, bisphenol A and ethyl paraben. Commercial TiO2 Degussa P25 was also used as a reference photocatalyst. The g-C3N4 catalysts demonstrated good photocatalytic activity which in some cases is comparable to TiO2 Degussa P25 leading to high removal percentages of the studied micropollutants under UV-A light irradiation. In contrast to TiO2 Degussa P25, g-C3N4 catalysts were also able to degrade the studied micropollutants under visible light irradiation. For all the studied g-C3N4 catalysts under both UV-A and visible light irradiation, the overall degradation rate decreases in the order of bisphenol A > diuron > ethyl paraben. Among the studied g-C3N4, the chemically exfoliated catalyst (g-C3N4-CHEM) showed superior photocatalytic activity under UV-A light irradiation due to its enhanced characteristics, such as pore volume and specific surface area and ~ 82.0 % in 6 min, ~75.7 % in 15 min and ~ 96.3 % in 40 min removals were achieved for BPA, DIU and EP, respectively. Under visible light irradiation, the thermally exfoliated catalyst (g-C3N4-THERM) demonstrated the best photocatalytic performance and the degradation ranged from ~29.5 to 59.4 % after 120 min. EPR data revealed that the three g-C3N4 semiconductors generate mainly O2•-, whereas TiO2 Degussa P25 generates both HO• and O2•-, the latter only under UV-A light irradiation. Nevertheless, the indirect formation of HO• in the case of g-C3N4 should also be considered. Hydroxylation, oxidation, dealkylation, dechlorination and ring opening were the main degradation pathways. The process proceeded without significant alterations in toxicity levels. Based on the results, heterogeneous photocatalysis using g-C3N4 catalysts is a promising method for the removal of organic micropollutants without the formation of harmful transformation products.

Unexpected growth promotion of Chlorella sacchrarophila triggered by herbicides DCMU.

The ecotoxicological effects of herbicide contamination on the autotrophic growth of microalgae in aquatic environments have been major concerns. However, little is known about the influence of herbicides on the mixotrophic growth of microalgae. This study investigated the ecotoxicological effect of 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (DCMU) on the mixotrophic growth of Chlorella sacchrarophila FACHB 4. Results showed that C. sacchrarophila in mixotrophy was more resistant to DCMU than in photoautotrophy. Moreover, a low content of DCMU (20-80 µg·L-1) promoted the mixotrophic growth of C. sacchrarophila, and the promotion effect was obviously enhanced with the increase in light intensity. The chlorophyll content and glucose absorption rate of C. sacchrarophila were found to increase after incubation with DCMU for 24 h. Transcriptome analyses revealed that the mechanism of DCMU to promote the mixotrophic growth of C. sacchrarophila was probably through accelerating glucose uptake and utilization, which was accomplished by reducing photodamage and increasing the chlorophyll content of C. sacchrarophila. This study not only revealed an unexpected bloom of mixotrophic microalgae triggered by herbicides, but it also shed new light on an effective and low-cost strategy to improve the microalgae productivity for utilization.

Toxicity of antifouling biocides on planktonic and benthic neotropical species.

Organotin-based (OTs: TBT and TPT) antifouling paints have been banned worldwide, but recent inputs have been detected in tropical coastal areas. However, there is a lack of studies evaluating the toxicity of both legacy and their substitute antifouling booster biocides (e.g., Irgarol and diuron) on neotropical species. Therefore, the acute toxicity of four antifouling biocides (TBT, TPT, Irgarol, and diuron) was investigated using the marine planktonic organisms Acartia tonsa and Mysidopsis juniae, the estuarine tanaid Monokalliapseudes schubarti (water exposure), and the burrowing amphipod Tiburonella viscana (spiked sediment exposure). Results confirmed the high toxicity of the OTs, especially to planktonic species, being about two orders of magnitude higher than Irgarol and diuron. Toxic effects of antifouling compounds were observed at levels currently found in tropical coastal zones, representing a threat to planktonic and benthic invertebrates. Furthermore, deterministic PNECmarine sediment values suggest that environmental hazards in tropical regions may be higher due to the higher sensitivity of tropical organisms. Since regulations on antifouling biocides are still restricted to a few countries, more ecotoxicological studies are needed to derivate environmental quality standards based on realistic scenarios. The present study brings essential contributions regarding the ecological risks of these substances in tropical and subtropical zones.