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Large amounts of trifluralin are applied each year for weed control; however, its effects on soil microbial communities and functions are unknown. Two agricultural soils, one silty loam and one silty clay were spiked with TFL (0, 0.84, 8.4, and 84 mg kg –1 ) and studied the effects using a laboratory microcosm approach. The half-lives were 44.19–61.83 d in all cases. Bacterial abundance increased 1.12–5.56 times by TFL, but the diversity decreased. From the next-generation sequencing results, TFL altered the bacterial community structure, which initially diverged from the control community structure, then recovered, and then diverged again. Linear discriminant analysis effect size indicated that Sphingomonas and Xanthomonadaceae were the predominant species on day 7 and 15 in TFL treatments. N 2 -fixing bacteria were initially increased, then decreased, and then recovered, and it was positively correlated with NH 4 + -N content. Compared with the control, ammonia-oxidizing bacteria were decreased by 25.51–92.63%, ammonia-oxidizing archaea were decreased by 17.12–85.21% (except day 7), and the NO 3 − -N concentration was also inhibited. In contrast to bacteria, fungal abundance was inhibited without any observable effects on fungal diversity or community structure. These results suggest that TFL impacts soil bacterial community and alters functional microorganisms involved in soil N processing. [ABSTRACT FROM AUTHOR]

An equilibrium passive sampler based on POM was first used to determine the C free of flubendiamide in water/sediment systems. The adsorption of flubendiamide by POM followed a first-order one-compartment uptake model and the POM-water partition coefficient was 1.90. The method was used to compare the efficiency of three biochars which were produced from crofton weed (BC-1, ∼500 °C), macadamia (BC-2, 550–660 °C) and wheat straw (BC-3, 550 °C). The Freundlich fit the sorption isotherm data well and the adsorption capacity was BC-1 > BC-3 > BC-2. The percent removal of the BC-1 was higher in acidic solutions. When different doses of BC-1 were added to two sediments, the C free of the flubendiamide was higher in the sediment with a low organic matter content (S-1). With an increase of BC-1, the C free was significantly reduced in S-1. A 30-day period of biochar-sediment contact time was sufficient for a reduction of freely dissolved flubendiamide in the case of the two sediments tested. In the combination of biochar addition (5%) and aging time (30 days), the maximum reductions were 87% and 60% in S-1 and S-2. Therefore, the reduction of bioavailability of the flubendiamide and pollution repair can be achieved by this process. [ABSTRACT FROM AUTHOR]

Highlights: [•] 100× recommended application rate reduced soil microbial activity. [•] 100× recommended application rate changed soil microbial community composition. [•] 100× recommended application rate changed microbial functional diversity. [•] Nitrogen-fixing gene abundance was reduced by high fomesafen application. [ABSTRACT FROM AUTHOR]

Ginger is consumed as a spice and medicine globally. However, pesticide residues in ginger and their residue changes during processing remain poorly understood. Our results demonstrate that clothianidin, carbendazim and imidacloprid were the top detected pesticides in 152 ginger samples with detection rates of 17.11–27.63%, and these pesticides had higher average residues of 44.07–97.63 μg/kg. Although most samples contained low levels of pesticides, 66.45% of the samples were detected with pesticides, and 38.82% were contaminated with 2–5 pesticides. Peeling, washing, boiling and pickling removed different amounts of pesticides from ginger (processing factor range: 0.06–1.56, most <1). By contrast, pesticide residues were concentrated by stir-frying and drying (0.50–6.45, most >1). Pesticide residues were influenced by pesticide physico-chemical parameters involving molecular weight, melting point, degradation point and octanol–water partition coefficient by different ginger processing methods. Chronic and acute dietary risk assessments suggest that dietary exposure to pesticides from ginger consumption was within acceptable levels for the general population. This study sheds light on pesticide residues in ginger from market to processing and is of theoretical and practical value for ensuring ginger quality and safety. [Display omitted] • Clothianidin, carbendazim and imidacloprid were the top detected pesticides. • Of the samples, 66.45% were detected with pesticides, and 38.82% were contaminated with 2–5 pesticides. • Pesticide residues were concentrated by stir-frying and drying. • Pesticide residues were influenced by pesticide physico-chemical parameters. • Chronic and acute dietary risks were considered to be acceptable. [ABSTRACT FROM AUTHOR]

The wide application of mesosulfuron-methyl (MS) in soil may affect soil microbial community, yet the information is limited. In this work, two distinct soil types from Anyang (AY) and Nanjing (NJ) were spiked with MS (0, 0.006, 0.06, or 0.6 mg kg–1) and incubated for 90 days. MS decreased bacterial and fungal (except the last sampling) abundance and altered their diversity and community. Five biomarkers of bacterial species may help MS degradation and more increased xenobiotics biodegradation pathways were also observed in 0.6 mg kg–1 treatment in AY soil. A co-occurrence network revealed the biomarkers grouped in one module in all AY soils, suggesting these biomarkers act in concert to degrade MS. MS impacted soil N transformation with increasing N 2 -fixing bacteria in both soils and ammonia-oxidising bacteria (AOB) in NJ and decreasing ammonia-oxidizing archaea (AOA) in AY. The contents of NO 3 –-N and NH 4 +-N were increased by MS. Structural equation models revealed that the abundance of bacteria and fungi was responsible for the NO 3 –-N and NH 4 +-N contents. In conclusion, this work aids safety assessments and degradation-related research of MS in soil. [Display omitted] • The interconnections of soil microorganism were more tightened under the interference of mesosulfuron-methyl. • More increased xenobiotics biodegradation pathways were observed in the highest mesosulfuron-methyl treated Anyang soil. • Biomarkers of bacteria from LEfSe contribute to MS degradation. • N-cycling were influenced by mesosulfuron-methyl. [ABSTRACT FROM AUTHOR]

Hydrolysis and photolysis are important degradation pathways of pesticides while their degradation in soil is a principal metabolic pathway. These processes might generate toxic chemicals and pose threats to the environment. As a member of the controversial neonicotinoid pesticides, the environmental fate and toxicity of imidaclothiz and its potential metabolites have remained ambiguous. Laboratory experiments were conducted to study the degradation kinetics, mechanisms and toxicity of imidaclothiz in aqueous solutions (pH = 4, 7, 9 buffer solutions and ultra-pure water) and soil (black soil, red soil and fluvo-aquic soil) under different conditions (25 ℃ and 50 ℃). The results showed that imidaclothiz was fairly stable in water and soil under natural conditions. Based on the mass accuracy of the parent chemical and conserved fragment ions, ten candidate degradation products were filtered out using UHPLC-QTOF-MS and the UNIFI system. Then, two of the candidates were synthesized, analysed, and compared with standards to confirm. The microscopic mechanisms of three degradation reactions (imidaclothiz degraded to M216, M216 degraded to M217 and M216 degraded to M198) were elucidated using theoretical calculations. The toxicity data from experiments and the ECOSAR prediction showed that imidaclothiz had low toxicity to Daphnia magna and Danio rerio and had high toxicity to Apis mellifera , with 50% of the degradation products in this study exhibiting higher toxicities to aquatic organisms than the parent chemical. ga1 • Imidaclothiz degraded slowly in soil and water under natural conditions. • Ten new degradation products of imidaclothiz were identified. • The mechanisms of the three degradation reactions of imidaclothiz were explained using theoretical calculations. • Two degradation products of imidaclothiz exhibited higher toxicities to aquatic organisms. [ABSTRACT FROM AUTHOR]

Highlights • The absolute configuration of propiconazole stereoisomers was determined for the first time. • There were 2.43–23.47 fold difference between stereoisomers in bioactivity. • There were 1.48–2.13 fold difference between stereoisomers in toxicity. • The bioactivity and toxicity of stereoisomers differed depending on organisms. • Stereoselectivity of propiconazole in soils only occurred under aerobic condition. Abstract Propiconazole is a widely used systemic agricultural triazole fungicide with two chiral centers. In the present study, systemic assessments of propiconazole stereoisomers are reported for the first time, including absolute configuration, stereoselective bioactivity toward pathogens (Ustilaginoidea virens, Magnaporthe oryzae, Fusarium moniliforme, Thanatephorus cucumeris, and Rhizoctonia solani), and stereoselective acute toxicity toward aquatic organisms (Scenedesmus obliquus , and Daphnia magna). Moreover, the stereoselective dissipation of propiconazole in three types of paddy soil under laboratory-controlled conditions (aerobic, anaerobic and sterile) was investigated. The degree of bioactivity and acute toxicity of the propiconazole stereoisomers differed depending on the type of target pathogens and non-target organisms. There were 2.43–23.47 and 1.48–2.13 fold differences between the best and worst stereoisomer in bioactivity and toxicity, respectively. Under aerobic conditions, (2S,4S)-propiconazole and (2S,4R)-propiconazole were preferentially degraded in the three types of soils. However, no significant stereoselectivity was observed under anaerobic and sterile conditions. Propiconazole was configurationally stable throughout the study. In comprehensive consideration of bioactivity, toxicity and environmental behavior, using stereoisomer mixture rather than pure stereoisomer may help to control more species of disease in practical application, and the stereoselectivity should be taken into consideration in risk assessment. [ABSTRACT FROM AUTHOR]

Cyflumetofen was widely applied in agriculture with its excellent acaricidal effect. However, the impact of cyflumetofen on the soil non-target organism earthworm (Eisenia fetida) is unclear. This study aimed to elucidate the bioaccumulation of cyflumetofen in soil-earthworm systems and the ecotoxicity of earthworms. The highest concentration of cyflumetofen enriched by earthworms was found on the 7th day. Long-term exposure of earthworms to the cyflumetofen (10 mg/kg) could suppress protein content and increases Malondialdehyde content leading to severe peroxidation. Transcriptome sequencing analysis demonstrated that catalase and superoxide-dismutase activities were significantly activated while genes involved in related signaling pathways were significantly upregulated. In terms of detoxification metabolic pathways, high concentrations of cyflumetofen stimulated the number of Differentially-Expressed-Genes involved in the detoxification pathway of the metabolism of glutathione. Identification of three detoxification genes (LOC100376457, LOC114329378, and JGIBGZA-33J12) had synergistic detoxification. Additionally, cyflumetofen promoted disease-related signaling pathways leading to higher disease risk, affecting the transmembrane capacity and cell membrane composition, ultimately causing cytotoxicity. Superoxide-Dismutase in oxidative stress enzyme activity contributed more to detoxification. Carboxylesterase and glutathione-S-transferase activation play a major detoxification role in high-concentration treatment. Altogether, these results contribute to a better understanding of toxicity and defense mechanisms involved in long-term cyflumetofen exposure in earthworms. [Display omitted] • Risk assessment and metabolic enrichment capacity of CYF on Eisenia foetida. • CYF caused oxidative stress toxicity by interfering with cell membrane structure. • Higher detoxification contribution of SOD, CarE, and GST according to IBRv2. • CYF activated stress responses and pathogenic pathways in earthworms. • Detoxification mechanism system of earthworms against CYF. [ABSTRACT FROM AUTHOR]

Pyrisoxazole, an isoxazoline-class fungicide, has been registered and used for approximately 19 years. However, its environmental transformation products (TPs) and corresponding ecotoxicological effects remain ambiguous. In this study, the photolysis, hydrolysis, and soil transformation behavior of pyrisoxazole were systematically investigated by indoor simulation experiments and analyzed by liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) and UNIFI software. Transformation products in different environemnts were effectively identfied by a proposed workflow, which organically combined suspect and non-target screening strategies. In total, 17 TPs were screened out. Eight TPs were confirmed using the corresponding reference standards. Structures of another 9 compounds were tentatively proposed based on diagnostic evidence. Among them, 14 products were reported for the first time. The transformation pathways of pyrisoxazole in soil and water were proposed. Pathway analysis demonstrated that the different pH of aqueous solutions had little effect on the pathways, while the influence of different soil types and oxygen conditions was evident. Finally, the toxicity of the proposed TPs to fish and daphnids was predicted using ECOSAR software. These proposed TPs in soil and water, transformation pathways, and predicted ecotoxicity information could provide systematic insight into the fate and environmental risks of pyrisoxazole. [Display omitted] • An effective environmental transformation product identification workflow of pesticides was proposed. • Fourteen transformation products of pyrisoxazole were proposed for the first time. • Eight transformation products were confirmed by corresponding reference standards. • Soil types and oxygen conditions influenced the kinds of transformation products. [ABSTRACT FROM AUTHOR]

Pyrisoxazole, an isoxazoline-class fungicide, has been registered and used for approximately 19 years. However, its environmental transformation products (TPs) and corresponding ecotoxicological effects remain ambiguous. In this study, the photolysis, hydrolysis, and soil transformation behavior of pyrisoxazole were systematically investigated by indoor simulation experiments and analyzed by liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) and UNIFI software. Transformation products in different environemnts were effectively identfied by a proposed workflow, which organically combined suspect and non-target screening strategies. In total, 17 TPs were screened out. Eight TPs were confirmed using the corresponding reference standards. Structures of another 9 compounds were tentatively proposed based on diagnostic evidence. Among them, 14 products were reported for the first time. The transformation pathways of pyrisoxazole in soil and water were proposed. Pathway analysis demonstrated that the different pH of aqueous solutions had little effect on the pathways, while the influence of different soil types and oxygen conditions was evident. Finally, the toxicity of the proposed TPs to fish and daphnids was predicted using ECOSAR software. These proposed TPs in soil and water, transformation pathways, and predicted ecotoxicity information could provide systematic insight into the fate and environmental risks of pyrisoxazole. [Display omitted] • An effective environmental transformation product identification workflow of pesticides was proposed. • Fourteen transformation products of pyrisoxazole were proposed for the first time. • Eight transformation products were confirmed by corresponding reference standards. • Soil types and oxygen conditions influenced the kinds of transformation products. [ABSTRACT FROM AUTHOR]

Difenoconazole is a widely used triazole fungicide that has been frequently detected in the environment, but comprehensive study about its environmental fate and toxicity of potential transformation products (TPs) is still lacking. Here, laboratory experiments were conducted to investigate the degradation kinetics, pathways, and toxicity of transformation products of difenoconazole. 12, 4 and 4 TPs generated by photolysis, hydrolysis and soil degradation were identified via UHPLC-QTOF/MS and the UNIFI software. Four intermediates TP295, TP295A, TP354A and TP387A reported for the first time were confirmed by purchase or synthesis of their standards, and they were further quantified using UHPLC-MS/MS in all tested samples. The main transformation reactions observed for difenoconazole were oxidation, dechlorination and hydroxylation in the environment. ECOSAR prediction and laboratory tests showed that the acute toxicities of four novel TPs on Brachydanio rerio , Daphnia magna and Selenastrum capricornutum are substantially lower than that of difenoconazole, while all the TPs except for TP277C were predicted chronically very toxic to fish, which may pose a potential threat to aquatic ecosystems. The results are important for elucidating the environmental fate of difenoconazole and assessing the environmental risks, and further provide guidance for scientific and reasonable use. [Display omitted] • Difenoconazole degrade faster under neutral or alkaline solutions and is stable in soils. • Four new transformation products were identified and confirmed by standards. • Transformation products are produced by oxidation, dechlorination and hydroxylation. • The degradation of difenoconazole reduces its toxicity to aquatic organisms. • Eleven phototransformation products could still be toxic to aquatic life. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN) has a potential hazard to human health, and is frequently found in agro-products. To minimize ZEN exposure to consumers, a novel metal-organic framework-based immunoassay system using zeolitic imidazolate framework-encapsulated horseradish peroxidase and goat anti-mouse IgG (HRP/Ab@ZIF-L) as labels was proposed for rapid and ultrasensitive detection of ZEN in agro-products. The HRP/Ab@ZIF-L not only maintained recognition ability of antibody and catalytic activity of enzyme, but also protected encapsulated proteins against high temperature, organic solvents and long term storage. Under optimal conditions, the detection limit of HRP/Ab@ZIF- L -based immunoassay reached 0.5 ng/L for ZEN, which was approximately 126-fold lower than that of conventional HRP-based immunoassay. Moreover, the proposed method showed an excellent selectivity, and a good dynamic linear detection for ZEN in the range of 0.5 ng/L to 0.476 μg/L. The recoveries of ZEN from spiked corn and wheat samples ranged from 84.50% to 96.70% with the relative standard deviation under 8.9%. In brief, the proposed immunoassay method has potential application for rapid and ultrasensitive detection of ZEN in agro-products. [Display omitted] • A novel enzyme-labeled antibody (HRP/Ab@ZIF-L) is prepared by a one-pot green synthesis method. • HRP/Ab@ZIF-L not only maintains biological activity of proteins, but also protects proteins against extreme conditions. • HRP/Ab@ZIF-L as a novel label is applied in immunoassay for zearalenone (ZEN) determination. • The detection limit of ZEN using HRP/Ab@ZIF-L is about 126-fold lower than that of conventional HRP-labeled antibody. [ABSTRACT FROM AUTHOR]

Pyrisoxazole is a chiral fungicide that is routinely applied to agricultural plant protection, but the potential environmental risk may be under- or over-estimated because the risk induced by stereoisomers have never been evaluated individually. Thus, we carried out a systemic evaluation of pyrisoxazole at the stereoisomeric level, including absolute configuration, stereoselective bioactivity, acute toxicity, and stereoselective dissipation behavior. There were 99.0–3545.3 fold difference in bioactivity toward six target pathogens (e.g., Alternaria solani) and 1.3–4.0 times difference in toxicity against aquatic organisms (Selenastrum capricornutum and Daphnia magna) between the best and worst stereoisomer. There appeared to be no significant stereoselective dissipation in all three kinds of soil under aerobic and anaerobic conditions. Stereoselective dissipation in buffer solution and river water only observed between diastereomers rather than between enantiomers. In addition, photolysis played a central role in the dissipation of pyrisoxazole in river water. RS -pyrisoxazole was 2.2- to 6.9-times more bioactive and 1.2- to 2.1-times more toxic than Rac -pyrisoxazole, and what is more, RS -pyrisoxazole degraded faster than other stereoisomers in river water. The result implicated that developing pure RS -pyrisoxazole as commercial product could reduce the input of inactive isomer on the basis of guaranteeing the efficacy against the target pathogens. ga1 • Systemic assessments of pyrisoxazole were explored for the first time. • RS -pyrisoxazole was more bioactive and more toxic than Rac -pyrisoxazole. • RS -pyrisoxazole with a high ecological risk degraded fastest in river water. • Traditional risk assessment may overestimate the environmental risk in water. • Development of RS -pyrisoxazole is beneficial for reduction of pesticide inputs. [ABSTRACT FROM AUTHOR]

• A novel degrader Providencia stuartii JD was the first strain of NDPS-degrading. • Strain JD degraded NDPS to simple products which were further mineralized. • Immobilization improved stability and adaptability of cells and enzymes of strain JD. • Immobilized cells and enzymes of strain JD efficiently removed NDPS from soils. • Strain JD promises the great potential to remove hazardous NDPS residues. The first potential degrader capable of detoxifying dimethachlon (NDPS) was isolated and identified as Providencia stuartii JD, whose free cells and freely crude enzymes degraded more than 80% and 90% of 50 mg L−1 NDPS in liquid culture within 7 d and 2 h, respectively. Strain JD metabolized NDPS through the typical pathway, in which NDPS was firstly transformed into succinic acid and 3, 5-dichloroanilin, and the latter was then converted to phenol, which was subsequently degraded to muconic acid further subjected to the mineralization. The immobilization obviously improved the stability and adaptability of cells and enzymes. In laboratory non-sterile soils treated by free or immobilized cells and enzymes, 50 mg kg-1 NDPS decreased to 15.66 and 13.32 mg kg-1, or 8.32 and 2.18 mg kg-1 within 7 d, respectively. In field, immobilized cells and enzymes exhibited significantly higher efficiencies in removing 20.250 kg a.i. ha-1 NDPS wettable powder from soils after 9 d (96.02% and 98.56%) than free cells and enzymes (79.35% and 66.45%). This study highlights that strain JD promises the great potential to remove hazardous NDPS residues and its immobilized cells and enzymes possess the more promising advantages in the bioremediation of NDPS-contaminated soils in situ. [ABSTRACT FROM AUTHOR]