Bioaccumulation, transformation and toxicity of imidacloprid and dinotefuran in Eisenia fetida under single and binary exposure scenarios.

Earthworms (Eisenia fetida) were exposed to individual and binary mixture of imidacloprid (IMI) and dinotefuran (DIN) at 0.05 and 0.5mg/kg for 28 days to investigate their bioaccumulation, transformation and toxicity. IMI was more easily absorbed by earthworms than DIN, and worms didn't accumulate or generate toxic metabolites. The obvious accumulation of neonicotinoids during later period caused significant neural dysfunction, especially when exposed to high-concentration IMI. Meanwhile, oxidative stress indicated by decreased SOD/CAT activity (33.2%-68.1%) and increased MDA (38.4%-55.0%) was induced by binary exposure with high-concentration IMI. By contrast, coelomocytes responded earlier and more strongly than oxidative responses. Coelomocytes' viability and mitochondrial membrane potential were inhibited (23.6%-91.7%) mainly by IMI and binary exposure. Coelomocytes' lactate dehydrogenase activity exerted a fluctuating pattern, suggesting irregular disturbance on cellular functions. This study highlights the role of coelomocytes and the need to consider binary/multiple scenarios and transformation of neonicotinoids in their risk assessment to earthworms.

Two-Dimensional Layered Nano-MoS2 Induces Earthworm Immune Cell Apoptosis by Regulating Lysosomal Maintenance and Function: Toward Unbiased Screening and Validation of Suspicious Pathways.

Molybdenum-based nanosheets (NSMoS2) are increasingly applied in various fields and undergoing relevant risk evaluations on subjectively hypothesized toxicity pathways. However, risk assessment should be unbiased and focus on appropriate end points to avoid biased prescreening. Here, we developed an adverse biological outcome screening strategy based on nontargeted functional protein profiles in earthworm (Eisenia fetida) immune cells exposed to NSMoS2 and their ionic counterpart (Na2MoO4). Through this framework, the apoptosis-related processes with distinct mechanisms were rapidly identified and thoroughly validated phenotypically. Specifically, upon exposure to 50 µg Mo/mL Na2MoO4, cellular signaling and energy homeostasis were disrupted within the transcription-translation biological chain. The autophagic pathway was activated, which, together with energy deprivation, phenotypically induced significant autophagy that ultimately led to apoptosis. In contrast, NSMoS2, tested at the same concentration, caused a reprogramming of apoptotic gene and protein expressions. Transcriptome plasticity facilitated the endocytic-adaptive transcriptional profile characterized by cytoskeleton remodeling and lysosome organization/movement under NSMoS2 exposure. Subcellular dynamics further revealed NSMoS2-induced lysosomal damage with a time-sensitive physiological window, ultimately mediating apoptosis. These findings provide a mechanistic and visual understanding of the distinct risk profile of NSMoS2 compared to molybdate, highlighting the importance of integrating nontargeted screening and phenotypic validation in early risk warning.

ECOTOXICITY OF ALKALINE RESIDUE FROM THE PULP AND PAPER INDUSTRY TO SOIL FAUNAL ORGANISMS.

The increased production and expanding demand for cellulosic products have required companies to provide solutions for the proper disposal of generated residues without compromising soil quality. In this context, the current research aimed at evaluating the ecotoxicological impacts of dregs application in subtropical soils. The experiments were carried out with the earthworm Eisenia andrei, the springtail Folsomia candida, and the potworm Enchytraeus crypticus in two subtropical soils (Neosol and Cambisol) collected in the southern region of Brazil. The considerable differences in texture and organic matter content motivated the choosing of these soils. The reproductive rate of all organisms was influenced, with varying EC50 values depending on the soil type. However, more pronounced effects were observed for Neosol. The springtail F. candida proved to be the most sensitive to contamination (EC50 = 5.8 g kg-1 for Neosol and 48.5 g kg-1 for Cambisol), followed by the earthworm E. andrei (EC50 = 62.4 g kg-1 for Neosol and 129.5 g kg-1 for Cambisol) and the potworm E. crypticus (EC50 = 67.2 g kg-1 for Neosol and 230.4 g kg-1 for Cambisol). As a result, while dregs can be used to correct soil acidity, they have been shown to have negative effects on important organisms responsible for functions critical to maintaining ecosystem quality.

Functional significance of earthworm clitellum in regulating the various biological aspects of cell survival and regeneration.

Earthworms are a highly abundant species in nature, with nearly 7000 different species being discovered. Despite the similarities in morphology among earthworm species, their regeneration capabilities vary based on the clitellum. The clitellum plays a crucial role in the clitellum-dependent worms, as it is involved in the processes of regeneration and reproduction in earthworms. The fascinating characteristic of the clitellum, which serves as a hub for stem cells in clitellum-dependent worms, plays a crucial role in various biological processes that require further exploration. This review focuses on the overall physiological functions and uncovers the lesser-known roles of the clitellum that have been documented in various research articles. In recent times, numerous studies have been conducted using the earthworm model to explore various areas. In that regard, the clitellum's different roles in regulating and controlling stem cells, the regeneration process, regulation of organogenesis, stress response, aging, autotomy, and various features have been briefly discussed. Ultimately, we emphasized the unique and versatile role of the clitellum in the animal model, making it an ideal choice for studying development, regeneration, stem cells, organogenesis, toxicology, autotomy, and aging response.

Effect of BF839 + earthworm protein supplement on motor and some non-motor symptoms of Parkinson's disease: a randomized clinical trial.

Introduction: Some studies have found that probiotics have the potential to treat PD, and earthworm protein is a traditional Chinese medicine used for the treatment of PD. The purpose of this study was to evaluate the safety and efficacy of Bacteroides fragilis 839 (BF839) + earthworm protein supplement as an adjunctive therapy for PD and to observe changes in the gut microbiota. Methods: Forty-six patients with PD were recruited for a 12-week 1:1 randomized, double-blind, placebo-controlled clinical trial to evaluate changes in motor and some non-motor symptom scores and detect metagenomic changes in the gut microbiota. Results: From baseline to 12 weeks, compared with placebo, the trial group showed significant reductions in the United Parkinson's Disease Rate Scale (UPDRS) total score (-7.74 ± 5.92 vs. -1.83 ± 4.14, p < 0.001), UPDRS part I (-0.72 ± 0.81 vs. -0.20 ± 0.72, p = 0.026), UPDRS part II (-2.50 ± 2.24 vs. -0.22 ± 1.98, p = 0.001), UPDRS part III (-3.43 ± 3.42 vs. -1.33 ± 2.65, p = 0.024), and UPDRS part IV (-1.13 ± 1.19 vs. -0.15 ± 0.57, p = 0.001). Significant reductions in the Hamilton Depression Scale-24 score (-3.91 ± 3.99 vs. +1.15 ± 3.42, p < 0.001), Self-Rating Anxiety Scale scores (-7.04 ± 5.71 vs. -1.23 ± 2.34, p < 0.001), and Constipation scoring system scores (-8.59 ± 4.75 vs. 0.27 ± 1.24, p < 0.001), were also noted. In the trial group, one patient experienced mild eczema and one suffered low blood pressure, which could not be conclusively attributed to supplementation. Compared to the placebo group, the trial group showed a marked increase in Enterococcus faecium and a decrease in Klebsiella. Conclusion: This study is the first to report that probiotics plus earthworm protein can remarkably improve the motor and some non-motor symptoms of PD without serious adverse effects. However, further clinical trials and exploration of the underlying mechanisms are required. Clinical trial registration: Clinical trial registry http://www.chictr.org.cn/, Identification No: ChiCTR2000035122.

Earthworms-enhanced bacterial degradation of the chiral fungicide penflufen R-enantiomer.

The widespread application of chiral fungicides as seed-coating agents in agriculture has led to serious residue accumulation in soil, increasingly drawing attention to soil pollution remediation strategies for chiral pesticides. This study explored the role of earthworms and soil microorganisms in selectively accelerating the degradation of penflufen in soil. The results showed that soil microorganisms significantly accelerated penflufen enantiomer degradation, particularly the R-enantiomer. Nocardioides, Variovorax, Arthrobacter, and Pseudomonas were identified as key degrading microorganisms associated with the preferential degradation of the R-enantiomer. The addition of earthworms further significantly enhanced the preferential degradation of the R-enantiomer. Importantly, earthworms markedly promoted the growth and reproduction of the four aforementioned degrading microorganisms in soil treated with enantiomers. Notably, the relative abundance of these degrading microorganisms was significantly higher in R-enantiomer-treated soil with earthworms than in soil treated with the S-enantiomer. Additionally, earthworms significantly increased the relative abundance of degradation genes p450, bphA1, and benA in the soil, especially in the R-enantiomer treated soil. Nocardioides, Variovorax, Arthrobacter, and Pseudomonas were identified as potential hosts for the degradation gene benA. More importantly, twelve strains of penflufen-degrading bacteria were isolated from the treated soil, of which eight belonged to the aforementioned four microorganisms and exhibited a remarkable ability to preferentially degrade the R-enantiomer. This finding highlights the potential of adding earthworms to soil, in conjunction with key degrading microorganisms, which preferentially accelerates penflufen R-enantiomer degradation.

Conservation agriculture practices impact on biological and microbial diversity in earthworm cast under maize-wheat system.

Soil degradation is a major global concern due to its negative impact on soil quality and the sustainability of agricultural resources. The conservation agriculture (CA) approach, which includes three key principles such as zero tillage, retention of crop residue and crop rotation has gained widespread adoption to help mitigate the climate change effects on agricultural soils and meet the growing demand for increased production. Earthworm communities, along with microbial activity and diversity, are highly sensitive to tillage practices. Additionally, microbial activity and diversity quickly respond to different cropping systems, making them effective indicators for detecting short-term changes in soil functioning. We therefore, assess the effects of CA innovative approached after 6-years on biological and microbial diversity within earthworm cast in maize-wheat system (MWS). The treatments consist of PBM-RN0/ZTW-RN0 (permanent beds No-N control-both residues removed and wheat with zero tillage); PBM+RN0/ZTW+RN0 (permanent beds No-N control-both residues retained)-50% of maize stover and 25% of wheat residue retained; PBM-RN120/ZTW- RN120 (permanent beds with 120 kg N ha-1 both residues removed wheat with zero tillage); PBM+RN120/ZTW+RN120 (permanent beds with 120 kg N ha-1 both residues retained and wheat with zero tillage) and FBM-RN120/CTW-RN120 (fresh beds in maize/CT in wheat with 120 kg N ha-1 both residues removed). The result of present study showed that activities of carbon (C) cycle-related enzymes in the cast soils viz., dehydrogenase (DHA), ß-glucosidase (ß-glu), cellulase, and xylanase were significantly higher under PBM+RN120/ ZTW+RN120 than under PBM-RN0/ZTW-RN0. Specifically, the activities of these enzymes were 21.5, 26.8, and 76.5% higher under the PBM+RN120/ZTW+RN120 treatment, respectively. Moreover, the Alk-P activity was found to be 1.3 times higher in the PBM+RN120/ZTW+RN120 treatment than in the PBM-RN0/ZTW-RN0 treatment. The bacterial, fungal, and actinomycete counts in the cast soil ranged from 6.87 to 7.47 CFU (colony forming units) x 106 g-1 soil, 3.87-3.30 CFU x 104 g-1 soil, and 5.09-5.67 CFU x 104 g-1 soil, respectively. Total organic carbon (TOC) showed significant increases of 34.6% under PBM+RN120/ZTW+RN120 as compared to PBM-RN0/ZTW-RN0. The less labile C (Frac. 3), total carbohydrate carbon (TCHO), phenol oxidase (PHE) and peroxidase (PER) were observed as the sensitive indicators under different tillage, rate of nitrogen and residue management practices. This study suggests that permanent beds with crop residue retention with balance fertilization practices can be recommended and popularized to the overall improvement of soil biological pools within earthworm casts in MWS.

Different mulch films, consistent results: soil fauna responses to microplastic.

Agricultural activities contribute to plastic pollution, with unintentional introduction and intentional use of plastic mulch films leading to the accumulation of microplastic particles in soils. The lack of removal techniques and scarce information on the effects on soil organisms, especially for biodegradable mulch films, necessitate an assessment of potential effects. This study aimed to elucidate the effects of mulch film microplastic on soil fauna by investigating reproduction output and subcellular responses before and after recovery from exposure. Two common soil organisms, Folsomia candida and Eisenia fetida, were exposed to petroleum-based polyethylene (PE) and biodegradable polylactic acid/polybutylene adipate terephthalate (PLA/PBAT) microplastic for 28 days, according to OECD guidelines 232 and 222, respectively. Juvenile numbers revealed no polymer- or concentration-dependent effects on E. fetida and F. candida reproduction after exposure to up to 5 and 10 g/kgdw soil, respectively. To provide a more sensitive and early indication of sublethal effects, subcellular responses in E. fetida were analyzed. Glutathione S-transferase (GST) activity increased with rising microplastic concentration; however, catalase (CAT), acetylcholine esterase (AChE) activity, and reactive oxygen species (ROS) did not differ from control levels. Further, the more environmentally relevant PE polymer was chosen for in-depth assessment of subcellular response after 28-day microplastic exposure and subsequent 28 days in uncontaminated soil with E. fetida. No significant differences in biomarker activity and stress levels were observed. We conclude that mulch film-derived microplastic did not adversely affect earthworm and collembolan species in this scenario, except for a slight induction in the detoxification enzyme glutathione S-transferase.

Oriented regulation of earthworm production and vermicompost quality by carbon bioavailability management.

Vermicomposting is an efficient bioconversion technology for recycling nutrients from organic waste materials. The biodegradability of raw materials has a significant impact on the earthworm transformation product. However, the management of carbon bioavailability is often overlooked during the vermicomposting process due to the varying degradability of C-rich source in different organic waste. This research aims to investigate the impact of different bioavailable carbon compositions on vermicomposting and to develop a strategy for efficient carbon management. The study involved systematic vermicomposting using four different biodegradable carbon sources (pineapple peels, rice straw, tomato straw, and sawdust) with varying carbon­nitrogen ratios (ranging from 24 to 42). The earthworm production and vermicompost quality were comprehensively evaluated, along with the influence of carbon components on microbial community structure. The results indicated that the optimal vermicomposting treatments were achieved at PCM24, RCM30, TCM30, and MCM30 treatments. Maintaining an approximate ratio of 1:(0.5-1.3) between available and recalcitrant carbon components based on the optimal carbon­nitrogen ratio was found to be optimal for regulating vermicomposting products. Increasing the proportion of available carbon enhanced the quality of vermicompost fertilizer, while a higher proportion of recalcitrant carbon could improve earthworm biomass production efficiency. Labile carbon proportion I (LCP1) and available carbon component (ACC) were identified as key indicators in influencing the formation of microbial community structure. Different carbon compositions led to the specific development and formation of microbial communities, further resulting in significant variations in vermicompost quality under the mediation of microbes. This study, for the first time, clarifies the impact of vermicomposting performance and microbial community from the perspective of carbon bioavailability, which is of great significance for the oriented regulation the vermicomposting efficiency and product in practice.

Effect of Sargassum on the Behavior and Survival of the Earthworm Eisenia Fetida.

The massive influx of Sargassum natans and S. fluitans to the shores of the Mexican Caribbean has raised concerns regarding their potential impact on soil quality and health in coastal and agroecosystems. The effects of Sargassum accumulation remain largely unexplored. This study aimed to assess the impact of Sargassum on soil ecosystems by examining the behavior and survival of the epigean earthworm Eisenia fetida. The earthworm was exposed to varying concentrations of Sargassum (0, 25, 50, 75, and 100%) in two toxicological tests. Results from the avoidance test demonstrated that E. fetida exhibited strong aversion (> 80%) to a diet containing 100% Sargassum. Conversely, the acute test revealed minimal mortality, but growth decreased with increasing Sargassum concentrations. These findings can serve as early warning bioindicators for assessing the environmental risk posed by Sargassum in soil ecosystems.

Morphophysiological and Histopathological Effects of Ammonium Sulfate Fertilizer on Aporrectodea trapezoides (Dugès, 1828) Earthworm.

The present study used the adult earthworm Aporrectodea trapezoides as a bioindicator species to look into the possible dangers of ammonium sulfate (AS) fertilizer. Two complementary toxicity tests were conducted to determine the LC50values, growth rate inhibition, morphological alterations, and histopathological texture of worms. The lethality test included four increasing concentrations of AS fertilizer (ranging from 2500 to 7500 mg/kg of dry soil weight (d.w.)), while sub-lethal concentrations were based on 10%, 30%, 40%, and 50% of the 14-day median lethal concentration (LC50), with a control group included for both tests. The LC(50) values for AS fertilizer were significantly higher at 7 days (4831.13 mg/kg d.w.) than at 14 days (2698.67 mg/kg d.w.) of exposure. Notably, earthworms exhibited significant growth rate inhibition under exposure to various concentrations and time durations (14/28 exposure days). Morphological alterations such as clitellar swelling, bloody lesions, whole body coiling and constriction, body strangulation, and fragmentation were accentuated steadily, with higher concentrations. Histopathological manifestations included severe injuries to the circular and longitudinal muscular layers, vacuolation, muscle layer atrophy, degradation of the chloragogenous tissue in the intestine, collapsed digestive epithelium of the pharynx with weak reserve inclusion, and fibrosis of blood vessels. These effects were primarily influenced by increasing concentrations of fertilizer and time exposure. The study highlights the strong relationship between concentration and exposure time responses and underscores the potential of A. trapezoides earthworms as valuable biological control agents against acidic ammonium sulfate fertilizer. Importantly, this research contributes to the use of such biomarkers in evaluating soil toxicity and the biological control of environmental risk assessment associated with chemical fertilizers.

Comparative Analysis of Bacterial Community Structures in Earthworm Skin, Gut, and Habitat Soil across Typical Temperate Forests.

Earthworms are essential components in temperate forest ecosystems, yet the patterns of change in earthworm-associated microbial communities across different temperate forests remain unclear. This study employed high-throughput sequencing technology to compare bacterial community composition and structure in three earthworm-associated microhabitats (skin, gut, and habitat soil) across three typical temperate forests in China, and investigated the influence of environmental factors on these differential patterns. The results indicate that: (1) From warm temperate forests to cold temperate forests, the soil pH of the habitat decreased significantly. In contrast, the physicochemical properties of earthworm skin mucus exhibited different trends compared to those of the habitat soil. (2) Alpha diversity analysis revealed a declining trend in Shannon indices across all three microhabitats. (3) Beta diversity analysis revealed that the transition from warm temperate deciduous broad-leaved forest to cold temperate coniferous forest exerted the most significant impact on the gut bacterial communities of earthworms, while its influence on the skin bacterial communities was comparatively less pronounced. (4) Actinobacteria and Proteobacteria were the predominant phyla in earthworm skin, gut, and habitat soil, but the trends in bacterial community composition differed among the three microhabitats. (5) Mantel tests revealed significant correlations between bacterial community structures and climatic factors, physicochemical properties of earthworm habitat soil, and physicochemical properties of earthworm skin mucus. The findings of this study offer novel perspectives on the interplay between earthworms, microorganisms, and the environment within forest ecosystems.

Water extract of earthworms mitigates kidney injury triggered by oxidative stress via activating intrarenal Sirt1/Nrf2 cascade and ameliorating mitochondrial damage.

ETHNOPHARMACOLOGICAL RELEVANCE: Ischemia-reperfusion (IR) injury can result in acute renal failure. Oxidative stress is a major factor in IR-induced cell death in the kidneys. According to traditional Chinese medicine, earthworms (Pheretima aspergillum) can be used to treat various kidney diseases. AIM OF THE STUDY: The present study was designed to understand the protective effects of the water extract of earthworms (WEE) against oxidative stress on the kidneys and the crucial molecular events associated with its nephroprotective activity. MATERIALS AND METHODS: Cytotoxicity caused by H2O2 in HEK293, HK2, and primary mouse renal tubular epithelial cells (TECs) was used to investigate the effect of WEE on oxidative stress-induced renal injury in vitro. IR-induced kidney injury was established using rats as an in vivo model. The WEE-mediated protection of the kidneys against oxidative stress was compared with that of glutathione, a common antioxidant used as a positive control. RESULTS: In HEK293 cells, HK2 cells, and primary mouse TECs, WEE relieved H2O2-induced mitochondrial damage, apoptosis, and ferroptosis. In kidney cells, WEE increased the expression of Sirt1, boosted LKB1 and AMPK phosphorylation, and upregulated nuclear Nrf2. Suppression of Sirt1 and LKB1 knock down abrogated WEE-induced protection against H2O2. WEE ameliorated IR-induced kidney injury and intrarenal inflammation in rats. In rat kidneys, WEE mitigated mitochondrial damage and suppressed IR-induced apoptosis and ferroptosis. Mechanistically, WEE increased Sirt1 expression, enhanced the phosphorylation of LKB1 and AMPK, and increased intranuclear Nrf2 levels in IR kidneys. IR treatment resulted in considerable increase in renal MDA levels and a prominent decrease in antioxidative enzyme activity. These lesions were significantly alleviated by WEE. CONCLUSIONS: WEE mitigated H2O2-induced cytotoxicity in kidney cells in vitro and improved IR-induced kidney damage in rats. Mechanistically, WEE potentiated the Sirt1/Nrf2 axis and relieved mitochondrial damage in the kidney cells. These events inhibited the apoptosis and ferroptosis induced by oxidative stress. Our findings support the potential application of WEE for the clinical treatment of kidney diseases caused by intrarenal oxidative stress.

Ecological risk assessment of castor oil based waterborne polyurethane: Mechanism of anionic/cationic state selective toxicity to Eisenia fetida.

Cationic and anionic castor oil-based waterborne polyurethanes (C-WPU/A and C-WPU/C) have great potential for development in agriculture. However, it is still unclear whether these polyurethanes are harmful or toxic to soil fauna. Based on multilevel toxicity endpoints and transcriptomics, we investigated the effects of C-WPU/A and C-WPU/C on earthworms (Eisenia fetida). The acute toxicity results showed that C-WPU/A was highly toxic to the earthworms, whereas C-WPU/C was nearly nontoxic. C-WPU/A significantly affected the body weight, burrowing ability and cocoon production rate of earthworms compared to C-WPU/C. After exposure to C-WPU/A, the results showed accumulation of reactive oxygen species (ROS), abnormal peroxidase activity, and increased malondialdehyde levels. Additionally, more serious histopathological damage was observed in earthworms, such as epidermal damage, vacuolization, longitudinal muscle disorganization, and shedding of intestinal epidermal cells. At the cellular level, C-WPU/A induced more severe lysosomal damage, DNA damage and apoptosis than C-WPU/A. C-WPU/A made more differentially expressed genes and considerably more enriched pathways at the transcriptional level than C-WPU/C. These pathways are largely involved in cell membrane signaling, detoxification, and apoptosis. These results provide an important reference for elucidating the selective toxicity mechanisms of C-WPU/A and C-WPU/C in earthworms.

Effects of sulfamethazine and tetracycline at molecular, cellular and tissue levels in Eisenia fetida earthworms.

Soil contamination by antibiotics is a global issue of great concern that contributes to the rise of bacterial antibiotic resistance and can have toxic effects on non-target organisms. This study evaluated the variations of molecular, cellular, and histological parameters in Eisenia fetida earthworms exposed to sulfamethazine (SMZ) and tetracycline (TC), two antibiotics commonly found in agricultural soils. The earthworms were exposed for 14 days to a series of concentrations (0, 10, 100, and 1000 mg/kg) of both antibiotics. SMZ and TC did not affect the survival of E. fetida, however, other effects at different levels of biological complexity were detected. The two highest concentrations of SMZ reduced the viability of coelomocytes. At the highest TC concentration, there was a noticeable decline in cell viability, acetylcholinesterase activity (neurotoxicity), and the relative presence of mucopolysaccharides in the epidermis (mucous production). Glutathione S-transferase activity decreased in all TC treatments and at the highest SMZ concentration. However, levels of malondialdehyde and protein carbonyls did not change, suggesting an absence of oxidative stress. Tetracycline was neurotoxic to E. fetida and changed the integrity of the epidermis. Both antibiotics altered the intestinal microbiota of E. fetida, leading to a reduction in the relative abundance of bacteria from the phyla Proteobacteria and Bacteroidetes, while causing an increase in the phylum Actinobacteroidota. All observed changes indicate that both SMZ and TC can disrupt the earthworms' immune system and gut microbiome, while fostering the growth of bacteria that harbour antibiotic resistance genes. Finally, both antibiotics exerted additional metabolic and physiological effects that increased the vulnerability of E. fetida to pathogens.

Advancing Soil Risk Assessment: A Novel Earthworm Cocoon Test with a Complementary Toxicokinetic-Toxicodynamic Modeling Approach.

In the current European Union pesticide risk assessment for soil organisms, effect endpoints from laboratory studies (Tier 1) and field studies (higher-tier risk assessment) are compared with predicted environmental concentrations in soil, derived from the proposed use pattern. The simple but conservative initial Tier 1 risk assessment considers a range of worst-case assumptions. In contrast, the higher-tier assessment focuses on specific conditions tested in the corresponding field study. Effect modeling, such as toxicokinetic-toxicodynamic (TKTD) modeling, is considered a promising future tool to address uncertainties in soil risk assessment, such as extrapolation to different ecological, pedo-climatical, or agronomical situations, or to serve as an intermediate tier for potential refinement of the risk assessment. For the implementation of TKTD modeling in soil organism risk assessment, data on earthworm growth and reproduction over time are required, which are not provided by the standard Organisation for Economic Co-operation and Development (OECD) 222 laboratory test. The underlying study with carbendazim presents a new earthworm cocoon test design, based on the OECD 222 test, to provide the necessary data as input for TKTD modeling. This proposed test design involves destructive samplings at days 7, 14, 21, and 28, enabling the determination of growth, cocoon number, and the number of juveniles hatched per cocoon in 7-day intervals. The new cocoon test allowed the disentanglement of the toxic effect of carbendazim in earthworms: At the highest concentration prominent effects on growth and reproductive output were observed, and the number of cocoons was significantly reduced compared to control. The results highlighted different physiological modes of action: effect on growth via higher maintenance costs as a primary mode of action as well as a reduced number of cocoons (effect on reproduction) and a lower number of juveniles hatching from each cocoon (hazard during oogenesis) as a secondary mode of action. We provide an example of how this new test's data can be used to feed a dynamic energy budget theory-TKTD model of Eisenia fetida. We also validate it against the original OECD 222 test design, outlining its potential future use in soil risk assessment. Environ Toxicol Chem 2024;00:1-10. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Metabolomics and microbiomics revealed the combined effects of different-sized polystyrene microplastics and imidacloprid on earthworm intestinal health and function.

The coexistence of pesticides and plastic film residues in agricultural soils poses a significant threat to soil organisms due to their potential long-term contamination and combined toxic effects. Specifically, earthworms are at risk of simultaneously ingesting residual pesticides and microplastics, yet the impact of this combined exposure on their intestinal health and function remains poorly understood. In this study, earthworm (Eisenia fetida) were single and combined exposed to three particle sizes (10 µm, 500 µm, and 2 mm) of polyethylene microplastics (PE MPs) and imidacloprid (IMI) for 28 days, respectively. Our findings underscore that compared to single exposures, the combined exposure inflicted more profound injuries on intestinal tissues and elicited a heightened activation of intestinal digestive enzymes. Furthermore, the combined exposure significantly perturbed the relative abundance of several pivotal metabolic-associated gut microbiota, fostering an enrichment of pathogenic species. Metabolomics analysis showed combined exposure increased differential metabolites, disrupting amino acid, fatty acid, and carbohydrate metabolism in earthworm intestines, potentially hindering nutrient absorption and causing toxic metabolite accumulation. An integrated omics analysis implies that combined exposures have the potential to disrupt the relative abundance of crucial gut microbiota in earthworms, thereby altering their intestinal metabolism and subsequently impacting intestinal health and functionality. Overall, the results reveal that combined exposure of IMI and PE MPs exacerbate the negative effects on earthworm gut health, and this study holds significant implications for the holistic understanding of the combined toxic effects of microplastics and pesticide on soil ecosystems.

The effect of soil parameters and earthworm abundance on the fine-scale nocturnal habitat use of the Eurasian woodcock (Scolopax rusticola).

The Eurasian woodcock prefers habitats where its main prey, earthworms, can be found in higher densities. Although they are forest-dwelling birds, they regularly visit pastures and natural grasslands at night, where earthworm abundance is generally higher. However, there is little information on fine-scale habitat use in relation to variation in habitat characteristics and prey availability, particularly beyond the breeding season. In our study, we investigated if the nocturnal occurrence of woodcocks during migratory stopover periods differed between two neighbouring fields, or management units, with similar vegetation structure, and if within-field variation in the spatial patterns of woodcock sightings were associated with fine-scale earthworm densities and soil parameters. Specifically, we used GPS tracking data of two tagged woodcocks and direct observation data to study patterns of occurrence of birds in a mixed forest-pasture landscape in Hungary during pre- and post-breeding periods. We compared these patterns with fine-scale soil characteristics and earthworm abundance, acquired by field sampling. We found that the field with higher earthworm abundance was visited by woodcocks more frequently, and this correlation was similarly observed at the intra-field level. Our results demonstrate that woodcocks select foraging sites with higher earthworm densities at multiple spatial scales, both between fields (coarse scale), and within fields (fine-scale). Considering that woodcocks tended to return to the same field to forage at night, the strong associations between occupancy and resources provide a basis for developing habitat management strategies at the field level for conservation. As earthworm densities and soil parameters are good indicators of woodcock foraging habitat, measuring those variables, at least at a coarse scale, could aid in predicting important habitats for the species across the landscape.

Pseudomonas putida HE alleviates glyphosate-induced toxicity in earthworm: Insights from the neurological, reproductive and immunological status.

The proceeding study aimed to isolate glyphosate-degrading bacteria from soil and determine optimal degradation conditions through single-factor experiments and response surface methodology. The detoxifying efficacy of the isolate on glyphosate was assessed using earthworm model. The results indicate that Pseudomonas putida HE exhibited the highest glyphosate degradation rate. Optimal conditions for glyphosate degradation were observed at an inoculation percentage of approximately 5%, a pH of 7, and a temperature of 30 °C. Glyphosate induced notable neurotoxicity and reproductive toxicity in earthworms, evidenced by reduced activity of the neurotoxicity-associated enzyme AChE. Additionally, an increase in the activities of catalase, superoxide dismutase, and lactate dehydrogenase was observed. H&E staining revealed structural disruptions in the earthworm clitellum, with notable atrophy in the structure of spermathecae. Furthermore, glyphosate activation of earthworm immune systems led to increased expression of immune-related genes, specifically coelomic cytolytic factor and lysozyme. Notably, the introduction of strain HE mitigated the glyphosate toxicity to the earthworms mentioned above. P. putida HE was able to increase soil enzyme activities that were reduced due to glyphosate. The isolate P. putida HE, emerged as an effective and cost-efficient remedy for glyphosate degradation and toxicity reduction in natural settings, showcasing potential applications in real ecological settings.

Evaluation of immunotoxicity of iron oxide nanoparticles on coelomocytes of Eisenia fetida.

Iron oxide nanoparticles (Fe3O4 NPs) have gained considerable attention due to their diverse applications in various fields. However, concerns about their potential toxic effects on the environment and living organisms have also emerged. In this study, we synthesized and characterized Fe3O4 NPs and assessed their immunotoxicity on the coelomocytes of Eisenia fetida. The Fe3O4 NPs were synthesized using a co-precipitation method, and their physicochemical properties were determined using techniques such as X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). The synthesized Fe3O4 NPs exhibited a uniform size distribution with spherical morphology and the phase purity was confirmed from XRD analysis. To evaluate the immunotoxicity of Fe3O4 NPs, Eisenia fetida coelomocytes were exposed to various concentrations of Fe3O4 NPs for 14 days. Furthermore, we analyzed the impact of Fe3O4 NPs on the biochemical parameters, including superoxide dismutase (SOD), catalase (CAT), acid phosphatase (APs), alkaline phosphatase (ALP), and total protein content (TPC), as well as conducted a histological examination. Biochemical analysis revealed significant alterations in the activity levels of SOD, CAT, APs, ALP, and TPC in the coelomocytes, indicating immune system dysregulation upon exposure to Fe3O4 NPs. Moreover, histological examination demonstrated structural changes, suggesting cellular damage caused by Fe3O4 NPs. These findings provide valuable insights into the immunotoxic effects of Fe3O4 NPs on Eisenia fetida and underscore the need for further investigation into the potential environmental impact of nanoparticles.