Biochemical and transcriptomic response of earthworms Eisenia andrei exposed to soils irrigated with treated wastewater

Exposure to polymetallic contaminated sites induced toxicological effects on chicken lungs: A multi-level analysis

Heavy metal pollution is an important environmental issue causing several hazards to organisms. In the present study, we investigated the uptake and accumulation of heavy metals (Pb, Cd, Cu, and Zn) in chicken lungs after six months of breeding on polymetallic-contaminated area in Jebel Ressas village. Genotoxicity in term of micronuclei frequency as well as oxidative stress in term of enzymatic activities of Catalase (CAT), Glutathion-S-Transferase (GST) and malondialdehydes accumulation (MDA) were performed. In addition, gene expression levels involved in oxidative stress genes (cat, sod and gst), metal homeostasis (mt1 and mt4) and DNA metabolism (p53, bcl2, caspase 3 and DNA ligase) were detected. Exposed chicken lungs revealed an important heavy metal accumulation of Cd and Zn co-occurring with oxidative status modulation. Transcriptomic results unveiled an upregulation of oxidative stress and homeostasis genes. On the other hand, genes involved in DNA metabolism indicated cellular functioning towards cells death and apoptosis modulation. Moreover, the histopathological examination revealed lung lesions in the chickens exposed to heavy metal contamination. Our study highlights the hazardous effects of heavy metal pollution on chicken respiratory system.

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa

Vermicomposting represents an environmentally friendly method for the treatment of various types of biowastes, including sewage sludge (SS), as documented in numerous studies. However, there are few papers providing insights into the mechanisms and toxicity effects involved in SS vermicomposting to present a comprehensive overview of the process. In this work, the vermiremediation of SS containing various micropollutants, including pharmaceuticals, personal care products, endocrine disruptors, and per/polyfluoroalkyl substances, was studied. Two SSs originating from different wastewater treatment plants (WWTP1 and WWTP2) were mixed with a bulking agent, moistened straw, at ratios of 0, 25, 50, and 75% SS. Eisenia andrei earthworms were introduced into the mixtures, and after six weeks, the resulting materials were subjected to various types of chemical and toxicological analyses, including conventional assays (mortality, weight) as well as tissue- and cell-level assays, such as malondialdehyde production, cytotoxicity tests and gene expression assays. Through the vermiremediation process significant removal of diclofenac (90%), metoprolol (88%), telmisartan (62%), and triclosan (81%) was achieved. Although the concentrations of micropollutants were substantially different in the original SS samples, the micropollutants vermiaccumulated to a similar extent over the incubation period. The earthworms substantially eliminated the present bacterial populations, especially in the 75% SS treatments, in which the average declines were 90 and 79% for WWTP1 and WWTP2, respectively. To the best of our knowledge, this is the first study to investigate the vermiremediation of such a large group of micropollutants in real SS samples and provide a thorough evaluation of the effect of SS on earthworms at tissue and cellular level.

New olive-pomace fertilizer tested with a 2-tiers approach: Biomarkers on Eisenia fetida, physiochemical effects on Solanum lycopersicum and Olea europaea

Every year, the olive oil industry generates a substantial amount of pomace, a semi-solid residue made up of skin, pulp, pit, and kernel fragments. Rather than being disposed of, the pomace can be dried and transported to an extraction facility where pomace oil can be extracted. Utilizing its high thermal capacity, the extracted pomace can be used as a supplementary fuel in the drying process, resulting in the production of ashes. In this study, the effect of pomace waste applied to the soil was investigated by testing two mixtures with different proportions of de-oiled pomace flour and kernel ash (50:50 and 70:30, respectively) in powder and pellet form. We used a dual approach, evaluating the effects of the mixtures on both soil communities and plant physiology and productivity, to assess the actual usability of the fertilizer in agriculture. The biomarker approach was valuable in assessing the sublethal effects of the two mixtures in powder form in soil. After 30 days of exposure, the bioindicator organism Eisena fetida showed lipid peroxidation, glutathione S-transferase and lactate dehydrogenase levels similar to the control, while lysozyme activity was reduced in all treatments. The powder mixture was lethal to the tomato plants, while there was no evidence of any damage to the olive trees. During 60 days of monitoring, both mixtures in pellet form showed a slight increase in physiological parameters, suggesting a benefit to the photosynthetic system. The improved carbon assimilation in tomato plants treated with the mixtures results in increased plant productivity, both in terms of number and weight of fruits, while maintaining the antioxidant content. This study paves the way for the use of the pomace mixture as a soil improver, thus increasing the value of this waste product.

Effects of diclofenac, sulfamethoxazole, and wastewater from constructed wetlands on Eisenia fetida: impacts on mortality, fertility, and oxidative stress

Soil contamination with micropollutants is an important global problem and the impact of these pollutants on living organisms cannot be underestimated. The effects of diclofenac (DCF) and sulfamethoxazole (SMX), their mixture (MIX), and wastewater containing these drugs on the mortality and reproduction of Eisenia fetida were investigated. The impact on the activities of antioxidant enzymes in earthworm cells was also assessed. Furthermore, the influence of the following parameters of the vertical flow constructed wetlands on wastewater toxicity was investigated: the dosing system, the presence of pharmaceuticals and the plants Miscanthus giganteus. The compounds and their mixture significantly affected the reproduction and mortality of earthworms. The calculated values of LC50,28 days values were 3.4 ± 0.3 mg kg-1 for DCF, 1.6 ± 0.3 mg kg-1 for SMX, and 0.9 ± 0.1 mg kg-1 for MIX. The EC50 (reproduction assay) for DCF was 1.2 ± 0.2 mg kg-1, whereas for SMX, it was 0.4 ± 0.1 mg kg-1, and for MIX, it was 0.3 ± 0.1 mg kg-1, respectively. The mixture toxicity index (MTI) was calculated to determine drug interactions. For both E. fetida mortality (MTI = 3.29) and reproduction (MTI = 3.41), the index was greater than 1, suggesting a synergistic effect of the mixture. We also observed a negative effect of wastewater (raw and treated) on mortality (32% for raw and 8% for treated wastewater) and fertility (66% and 39%, respectively) of E. fetida. It is extremely important to analyze the harmfulness of microcontaminants to organisms inhabiting natural environments, especially in the case of wastewater for irrigation of agricultural fields.

Combined toxicity of Cd and 2,4-dichlorophenoxyacetic acid on the earthworm Eisenia andrei under biochar amendment

Due to anthropogenic activities, various pollutants can be found in agricultural soil, such as cadmium (Cd) and 2,4-dichlorophenoxyacetic acid (2,4-D). They are highly toxic and can have a negative impact on soil fertility. For remediation strategies, biochar has acquired considerable attention due to its benefits for agriculture. However, we should recognize the ecological risk posed by biochar use. In addition, little is known about its non-desirable effects on soil organisms such as earthworms, especially in the case of soil remediation. In this study, earthworms (Eisenia andrei) were exposed to soil contaminated with Cd (0.7 mg/kg), (2,4-D) (7 mg/kg), and a mixture of the two in the presence and absence of biochar (2%). A 7- and 14-day incubation experiment was carried out for this purpose. Cd and 2,4-D uptakes in earthworms' tissues, oxidative stress, cytotoxic response, DNA damage, histopathological changes, and gene expression level were assessed. Results suggested that biochar increased the bioavailability of Cd and 2,4-D and the frequency of micronuclei (MNi) and decreased the lysosomal membrane stability (LMS) in earthworms. Also, histopathological examination detected numerous alterations in animals exposed to the contaminants without any amelioration when biochar was added. The biochemical response of earthworms in terms of oxidative stress demonstrates that in the presence of biochar, animals tend to alleviate the toxicity of Cd and 2,4-D. This was also supported by transcriptomic analyses where expression gene levels related to oxidative stress were upregulated in earthworms exposed to Cd and 2,4-D + biochar. The present investigation brought new insights concerning the use of biochar in agriculture.

The Effect of Nickel Exposure on Oxidative Stress of Vicia faba Plants

Heavy metal contamination is a serious threat for terrestrial ecosystems. Thus, they could be accumulated in living organisms leading consequently to harmful consequences. In this context, the present work aims to evaluate the effects of four increasing Nickel (Ni) nominal concentrations (T: 0 mg/kg, C1: 150 mg/kg, C2: 250 mg/kg, C3: 500 mg/kg) on agronomic and biochemical parameters in bean (Vicia faba) plants. The measured exposure concentrations were in the range of 96.69%-104.18% of the nominal concentrations. Bean's responses were evaluated at biometric levels, chlorophyll content and biochemical parameters namely catalase glutation-S-transferase activities and malondialdehyde content, in booth parts of plants. Our data revealed a marked negative effect of Ni exposure on bean plant development and chlorophyll content. Biochemical biomarkers reported that plants anti-oxidative defense system has been significantly affected specially in roots at the high Ni concentration. Briefly, resistance mechanisms of Vicia faba to Ni seem to imply an activation of the antioxidant system and a limitation of the reactive oxygen species.

Ecotoxicological responses of Eisenia andrei exposed in field-contaminated soils by sanitary sewage

The disposal of untreated sanitary sewage in the soil has several consequences for human health and leads to environmental risks; thus, it is necessary investigating, monitoring and remediating the affected sites. The aims of the current study are to evaluate ecotoxicological effects on Eisenia andrei earthworms exposed to soil subjected to sources of sanitary sewage discharge and to investigate whether prevention values established by the Brazilian legislation for soil quality, associated with the incidence of chemical substances in it, are satisfactory enough to assure the necessary quality for different organisms. Earthworms' behavior, reproduction, acetylcholinesterase activity, catalase, superoxide dismutase and malondialdehyde levels were evaluated. The reproduction and behavior of earthworms exposed to sanitary sewage were adversely affected. Increased superoxide dismutase and catalase activity acted as antioxidant defense mechanism. Significantly increased lipid peroxidation levels and acetylcholinesterase activity inhibition have indicated lipid peroxidation in cell membrane and neurotransmission changes, respectively. Results have confirmed that sanitary sewage induced oxidative stress in earthworms. In addition, based on biochemical data analysis, the integrated biomarker response (IBR) has evidenced different toxicity levels in earthworms between the investigated points. Finally, results have indicated that effluents released into the soil, without proper treatment, lead to contaminant accumulation due to soil saturation and it can hinder different processes and biological development taking place in the soil. In addition, the current study has shown that physical-chemical analyses alone are not enough to assess soil quality, since it is also requires adopting an ecotoxicological approach. Brazilian legislation focused on soil quality must be revised and new guiding values must be proposed.

Enantioselective toxicity and oxidative stress effects of acetochlor on earthworms (Eisenia fetida) by mediating the signaling pathway

Acetochlor (ACT) as a widely used chiral chloroacetamide herbicide is appropriate to evaluate the potential toxicity in soil ecosystems at enantiomeric level. The acute and subchronic toxicities of R-acetochlor (R-ACT) and S-acetochlor (S-ACT) on earthworms (Eisenia fetida) were investigated in the present study. Residual analyses showed that S-ACT degraded faster than R-ACT in artificial soil with half-lives of 16.5 and 21.7 d, respectively. Additionally, significant enantioselective acute toxicity in earthworms from between S-ACT and R-ACT (p < 0.05) was observed, and the acute toxicity of R-ACT were 1.9 and 1.5 times higher than those of S-ACT in the filter paper test and artificial soil test. The hydroxyl radical (OH^-) content, superoxide dismutase (SOD) and antioxidant enzyme catalase (CAT) activities, and cytochrome P450 content in earthworms significantly increased under the influence of ACT enantiomers; however, the acetylcholinesterase (AchE) activity was significantly inhibited after exposure to the two enantiomers. Moreover, lipid peroxidation and DNA damage were induced by ACT enantiomers. The results of transcriptome sequencing indicated that R-ACT induced a stronger oxidative stress effect than S-ACT in earthworms by mediating signaling pathways, which may be the primary reason for the enantioselective toxicity between S-ACT and R-ACT. Overall, the results demonstrated that R-ACT has a higher risk than S-ACT in the soil environment, which is important for understanding the enantioselective behavior of chloroacetamide pesticides.

Transcriptome, bioaccumulation and toxicity analyses of earthworms (Eisenia fetida) affected by trifloxystrobin and trifloxystrobin acid

As a promising fungicide, the potential environmental risk of trifloxystrobin (TFS) and its main metabolism trifloxystrobin acid (TFSA) in soil environment should be given special attention. The present study investigated the potential risks of TFS and TFSA in soil environment to earthworms (Eisenia fetida) through measuring several biomarkers. Residual analysis showed that TFSA was more stable than TFS in artificial soil with half-lives ranging from 138.6 to 231.0 d and 20.4-24.7 d, respectively. Additionally, the accumulation of TFS in earthworms increased in the beginning and then decreased from day 14, while that of TFSA continuously increased. At concentrations of 4.0 mg/kg and 10.0 mg/kg, the weight and lysosomal membrane stability of earthworms were reduced; however, the superoxide dismutase (SOD) activity, glutathione-S-transferase (GST) activity and malondialdehyde (MDA) content in earthworms were enhanced by TFS and TFSA. Moreover, the growth inhibition effect and the oxidative damage level induced by TFSA to earthworms were higher than those induced by TFS. The transcriptome analysis date indicated that the differentially expressed genes (DEGs) in both TFS and TFSA treatments were mainly enriched in ribosome pathway and lysosome pathway, finally affecting the protein synthesis and proteolysis in earthworms. The findings of the present study indicated that TFSA may pose a higher risk in the soil environment than TFS.

Impact of Intensive Farming on Soil Heavy Metal Accumulation and Biomarkers Responses of Earthworms Eisenia andrei

In this work, we propose to evaluate the effect of agriculture intensification under greenhouses on the biochemical and transcriptomic responses of the earthworms Eisenia andrei. This work was conducted on two sites in Téboulba and Sahline (Monastir governorate) and a control site in an experimental plot that is undergoing organic farming. For this purpose, the earthworms Eisenia andrei were exposed to the soils during 7 and 14 days. The physicochemical properties of the soils were analyzed. The biochemical biomarkers of metallothioneins (MTs) and malondialdehyde (MDA) accumulations were also assessed. Moreover, the gene expression level of the MTs was analyzed. The results of our study revealed a significant trace element accumulation accompanied by a high level of MDA and MT proteins. Moreover, a significant expression of the MT gene was observed in earthworms exposed to the soils from Sahline and Téboulba. Hence, this work reveals that intensive agriculture can affect the biological responses of earthworms and consequently, the soil's biofertility.

Earthworm Eisenia andrei modulates oxidative stress in bean plants Vicia faba irrigated with treated wastewater

With respect to reducing the pressure on freshwater resources, treated wastewater (TWW) irrigation represents a sustainable alternative in agriculture. Due to their low quality and variable composition, TWW could entail harmful consequences for living organisms in terrestrial ecosystems. This study aims to evaluate how earthworm (Eisenia andrei) can modulate oxidative stress in bean plants (Vicia faba) that are irrigated over a course of 60 days with two doses of TWW (50 and 100%) in addition to a control condition (0%) irrigated with distilled water. This is achieved by measuring glutathione-S-transferase (GST) activity and malondialdehyde accumulation (MDA) in plants. Furthermore, catalase (CAT), GST, MDA, and acetylcholinesterase (AChE) activities of the earthworms are also assessed. Our results show that growth and physiological parameters are modified when applying TWW irrigation. Moreover, oxidative stress apprehended by GST activity and MDA accumulation is exacerbated in V. faba plants after exposure to increased TWW doses. Similarly, TWW irrigation enhances oxidative stress parameters in earthworms with a crucial decrease in AChE activity. In addition, the presence of earthworms increases growth and physiological parameters; it also results in a significant reduction in GST activity and MDA rate in V. faba plants. Our results provide new insights into the impact of TWW irrigation on soil organisms and the importance of earthworms in the reduction of oxidative stress in plants.

Earthworms and vermicompost: an eco-friendly approach for repaying nature's debt

The steady increase in the world's population has intensified the need for crop productivity, but the majority of the agricultural practices are associated with adverse effects on the environment. Such undesired environmental outcomes may be mitigated by utilizing biological agents as part of farming practice. The present review article summarizes the analyses of the current status of global agriculture and soil scenarios; a description of the role of earthworms and their products as better biofertilizer; and suggestions for the rejuvenation of such technology despite significant lapses and gaps in research and extension programs. By maintaining a close collaboration with farmers, we have recognized a shift in their attitude and renewed optimism toward nature-based green technology. Based on these relations, it is inferred that the application of earthworm-mediated vermitechnology increases sustainable development by strengthening the underlying economic, social and ecological framework.