Search Results (159)

Microplastic (MP) contamination in soils has raised widespread concern, yet the extent to which soil matrices regulate MP toxicity remains insufficiently characterized. In this study, the acute and subchronic toxicity of polystyrene (PS) to the earthworm (Eisenia fetida) was analyzed in artificial soil and three types of natural soils (lou soil, black soil and latosol soil). The 28 d LC₅₀ (50% lethal concentration) of PS in artificial soil was 130.86 g kg⁻¹, whereas it decreased to 39.71 and 39.23 g kg⁻¹ in lou and latosol soil, respectively, and increased to 175.13 g kg⁻¹ in black soil, indicating that soil physicochemical properties may modulate MP toxic potency. Across all soil types, PS exposure triggered reactive oxygen species (ROS) accumulation in earthworms, which in turn activated antioxidant and detoxification enzymes (superoxide dismutase, catalase, and glutathione S-transferase) and ultimately led to lipid peroxidation and DNA damage. Assessment via the integrated biomarker response index suggested divergent PS toxicity across soils, indicating inconsistencies between artificial soil and natural soils. Notably, this study was conducted under controlled laboratory conditions using a single polymer type, particle size, and test organism, and therefore the observed soil-dependent toxicity patterns may not be directly extrapolated to other MP types, sizes, or soil biota. Overall, our study suggested that the toxicity data derived from artificial soil cannot fully represent the real effects in natural soils, providing valuable insights for elucidating the realistic toxicity of MPs. Full article

Accurate species identification is essential for biodiversity studies, ecological monitoring, and biosecurity, but current molecular approaches rely on PCR amplification, which requires universal primers. Here, we evaluated the possibility of primer-free species identification via direct RNA sequencing (dRNA-seq) by using Oxford Nanopore Technology (ONT). Total RNA isolated from three major eukaryotic kingdoms—fungal (Tuber magnatum Picco 1788), plant (Corylus avellana L. 1753), and animal (Eisenia fetida Savigny 1826) specimens—was sequenced without reverse transcription and PCR amplification. Taxonomic assignments based on similarity to ribosomal nuclear (fungi and animals) and chloroplast (plant) transcripts enabled reliable host species identification. Ribosomal RNA reads dominated the datasets and supported accurate identification of the target organisms, while additional sequences revealed associated microbiota and co-occurring taxa. Notably, dRNA-seq successfully detected symbiotic bacteria in E. fetida and latent fungal infection in C. avellana, highlighting the method sensitivity. However, the complex organization of nuclear ribosomal gene clusters may complicate taxonomic assignment in plants, underscoring the need for improved analytical pipelines. Overall, our results provide proof of concept that dRNA-seq enables primer-independent species identification while simultaneously providing insights into the host microbiomes. Direct sequencing of naturally present RNA molecules generated sufficient sequence information for species identification across different taxonomic kingdoms, indicating the technical feasibility of the developed technique. Further validation using larger biological datasets and direct comparisons with conventional sequencing methods will determine its wider applicability as an innovative and complementary species identification approach. Full article

The accumulation of agricultural waste poses significant agronomic and environmental challenges in tropical smallholder farming systems where organic wastes remain underutilized. This study evaluated the effectiveness of vermicomposting with Eisenia fetida in enhancing nutrient recovery and improving the quality of organic fertilizers produced from agricultural waste. Four substrate treatments—poultry manure and vegetable waste (T1), cow dung, chicken manure, and vegetable waste (T2), cow dung and vegetable waste (T3), and a control without earthworms (T4)—were assessed over a period of 60 days. Key physicochemical properties evaluated included bulk density, pH, electrical conductivity, organic carbon, total nitrogen, available phosphorus and potassium, and the C:N ratio. Vermicomposting significantly improved nutrient composition, with the C:N ratio decreasing from 26.43 in the control treatment to 12.23, indicating enhanced compost maturity. Treatment T2 recorded the highest concentrations of total nitrogen (2.63%), phosphorus (1.21%), and potassium (1.45%). A significant reduction in organic carbon also indicated enhanced mineralization during the decomposition process. Compared with traditional composting, vermicomposting improved nutrient availability, compost maturity, and overall compost quality. These findings demonstrate that vermicomposting is an effective resource recovery strategy for converting agricultural waste into nutrient-rich organic fertilizer while supporting sustainable and climate-resilient agricultural systems. Full article

The accumulation of agricultural residues represents a major environmental challenge in developing countries, particularly in tropical regions where inadequate waste management contributes to environmental degradation. Vermicomposting has emerged as a sustainable technology capable of transforming organic waste into nutrient-rich fertilizers through the combined activity of earthworms and microorganisms. This study evaluated the influence of different agricultural residues on the physicochemical properties of vermicompost under tropical conditions in Mozambique. The experiment was conducted at the experimental field of the Catholic University of Mozambique—Faculty of Engineering in Chimoio district, using three substrate types: leguminous residues (T1), cereal residues (T2), and horticulture residues (T3). Each treatment was combined with poultry manure in a 1:1 ratio. Vermicomposting was carried out using Eisenia fetida. Because treatments were not independently replicated, results are presented as descriptive physicochemical characterizations (means ± SD of analytical subsamples). All treatments produced vermicompost with physicochemical characteristics consistent with established maturity criteria: pH 8.03–9.07, moisture 50–76%, and electrical conductivity 527–939 µS/cm, C/N ratio ranged from 15.56 to 20.19, total nitrogen ranged from 1.2 to 1.8%, phosphorus from 0.6 to 0.9%, and potassium from 1.1 to 1.5%. T1 (leguminous residues + poultry manure) showed the highest nutrient concentrations and lowest C/N ratio. These descriptive findings suggest that vermicomposting represents a promising strategy for recycling agricultural residues into vermicompost with characteristics consistent with established maturity criteria, highlighting the importance of substrate selection. The findings suggest that vermicomposting is a promising strategy for sustainable waste management and soil fertility improvement in tropical smallholder systems. Full article

A sustainable method of improving soil fertility and developing climate-resilient cropping systems is vermicomposting agricultural waste. This study hypothesized that vermicompost derived from mixed organic agricultural wastes would significantly improve soil fertility, crop productivity, and drought resilience compared to single-substrate treatments and the unamended control. The effects of vermicompost generated from mixed organic wastes using Eisenia fetida on soil quality, crop performance, and drought resilience of lettuce (Lactuca sativa, Eden variety) were evaluated in this study using a randomized complete block design. Crop performance indicators included germination, growth characteristics, biomass, SPAD chlorophyll content, and yield, while soil physicochemical properties, including pH, organic carbon, total nitrogen, available phosphorus, exchangeable potassium, electrical conductivity (EC), and cation exchange capacity (CEC), were assessed both before and after amendment application. The effects of drought stress were evaluated using leaf surface temperature, wilting score, recovery time, and survival rate. The results demonstrated that vermicompost application significantly improved soil fertility and crop performance relative to the control treatment (p < 0.05). The best-performing treatment (T2) increased soil organic carbon by approximately 22–28%, total nitrogen by 18–24%, available phosphorus by 20–27%, and exchangeable potassium by 16–21% compared with the control. Fresh biomass increased by approximately 14–17%, marketable yield improved by 16–24%, and SPAD chlorophyll values increased by nearly 20%, indicating enhanced photosynthetic efficiency and nutrient uptake. T2 showed the most resilience under drought stress, with ~94.9% survival rate, reduced wilting severity, shortened recovery time and sustained stable leaf temperature (~27.8 °C), whereas low-performing treatments and the control recorded survival rates of only ~70–78%. Mixed organic waste substrates consistently outperformed single-substrate treatments, demonstrating synergistic effects on nutrient cycling, microbial activity, soil structural quality, and drought tolerance. These findings provide quantitative evidence that vermicomposting can simultaneously enhance soil fertility, crop productivity, and drought resilience, highlighting its strong potential as a scalable climate-smart strategy for sustainable agriculture, circular bioeconomy development, and organic waste valorization in smallholder farming systems. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent environmental contaminants of growing concern for soil ecosystems, yet their effects on the humoral arm of innate immunity in soil invertebrates remain poorly characterized. Here, we used the earthworm Eisenia fetida to screen 31 legacy and emerging PFAS congeners for their ability to modulate the hemolytic activity of cell-free coelomic fluid, a functional readout of soluble immune effectors including the pore-forming toxin lysenin. Earthworms were exposed under OECD 207 contact-filter conditions at two concentrations (0.6 and 229 µM) for 72 h, after which decellularized coelomic fluid was tested against sheep erythrocytes. To dissect direct biochemical interference from organism-mediated regulation, the same panel was also applied ex vivo (2.5 µM) to coelomic fluid from unexposed earthworms. In vivo, PFASs produced markedly heterogeneous, congener-specific responses: PFBS, PFBA and PFMOPrA suppressed hemolytic activity, whereas PMDA, PFHxA and HFPO-DA enhanced it. In contrast, ex vivo exposure produced a consistent, broad inhibition of hemolysis, indicating a direct interaction of PFASs with soluble immune proteins. Proteomic profiling of the lysenin family under PFOA and HFPO-DA suggested isoform-level reweighting rather than uniform abundance shifts, although effects did not survive multiple-testing correction. Together, these data show that PFASs act as congener-specific immunomodulators of extracellular humoral defense in E. fetida and identify candidate congeners for confirmatory mechanistic studies. Full article

Phytoremediation is a sustainable approach for the remediation of heavy metal–contaminated soils; however, the management of contaminated biomass generated during this process remains an insufficiently addressed challenge. Such biomass constitutes a secondary waste stream that may release mobile pollutants and pose environmental risks. In this study, an integrated ecotoxicological assessment framework was applied to evaluate phytoremediation-derived biomass and its transformation products obtained via pyrolysis. Two types of woody biomass with different heavy metal contents and their corresponding biochars produced at 700 °C were investigated. A multitrophic battery of bioassays combining direct exposure assays using terrestrial organisms (higher plants, Eisenia fetida, and soil microbial activity) with leachate-based assays using aquatic organisms (Lemna minor, Daphnia magna, and Aliivibrio fischeri) was applied. Untreated biomass exhibited high to extreme toxicity in aquatic systems (toxic units, TU >100) and significant phytotoxic effects. Pyrolysis substantially reduced contaminant mobility and ecotoxicity of leachates, resulting in lower toxicity (TU typically <15) and no significant effects on plant growth, earthworm survival, or soil microbial functional diversity. Residual toxicity was linked to elevated pH and trace amounts of thermally generated organic substances. These results demonstrate that pyrolysis effectively reduces the environmental risk of contaminated biomass and supports the use of multitrophic ecotoxicological testing for safe waste valorization within circular economy strategies. Full article

The valorization of agro-industrial residues and sewage sludge into value-added products through vermicomposting represents a promising strategy for nutrient recycling and waste reduction. This study evaluated the effects of aqueous extracts obtained from five vermicomposts (VC1-VC5) produced from different mixtures of vineyard and winery residues and sewage sludge on cucumber (Cucumis sativus L.) seedlings grown under in vitro conditions. The aqueous extracts (10%, w/v) were characterized in terms of pH, electrical conductivity, and total polyphenolic content, and applied to cucumber seedlings cultivated for 30 days under sterile and controlled in vitro conditions using commercially available peat pellets (Jiffy-7^®). Seedling development was monitored throughout the experiment, and morphological and biochemical parameters were assessed at the end of the 30-day assay. All extracts supported seedling development, with no evidence of phytotoxicity. The application of VC2 and VC4 extracts resulted in significant increases in fresh and dry weight, while VC2 led to higher chlorophyll and carotenoid contents. Conversely, VC3 and VC5 extracts were associated with slight reductions in growth parameters and photosynthetic pigment content. Correlation analysis suggested positive associations between biomass accumulation and chlorophyll content, and negative association between total polyphenolic content and stem growth. Overall, the results indicate that aqueous vermicompost extracts were not phytotoxic under the tested conditions, although their effects appear to depend on extract composition, highlighting the importance of feedstock selection for sustainable horticultural applications. Full article

Glitter is a distinctive and largely overlooked form of primary microplastic. Unlike more commonly studied microplastics, glitter particles are typically flat, highly reflective, multi-layered, and are composed of polymers such as polyethylene terephthalate, polyvinyl chloride with metallic coatings and a wide range of additives. In response to regulatory restrictions on intentionally added microplastics and increasing consumer demand, “eco-friendly” alternatives based on modified regenerated cellulose, cellulose nanocrystals, or mica have been introduced, although their environmental safety remains insufficiently characterized. This review synthesizes current knowledge on the environmental occurrence and ecotoxicological effects of both conventional and biodegradable glitters. A systematic literature search in Scopus identified 15 peer-reviewed experimental studies meeting predefined inclusion criteria. Evidence spans a wide range of taxa, including bacteria (i.e., Aliivibrio fischeri), microalgae and cyanobacteria (i.e., Phaeodactylum tricornutum, Raphidocelis subcapitata, Microcystis aeruginosa), aquatic plants (i.e., Lemna minor, Egeria densa), marine and freshwater invertebrates as crustaceans (i.e., Daphnia magna), bivalves (i.e., Mytilus galloprovincialis), sea urchins (i.e., Paracentrotus lividus), brine shrimp (Artemia sp.) and terrestrial soil fauna (Eisenia fetida, Folsomia candida). Results indicate that glitter cannot be treated as a uniform stressor: biological responses vary markedly with particle size, shape, colour, polymer type, additive composition, and weathering time, and leachates often exert stronger effects than intact particles. Reported impacts include impaired photosynthesis and growth, oxidative stress, developmental abnormalities, altered energy metabolism, and reduced reproduction. Substantial gaps remain regarding environmental concentrations, ageing processes, mixture effects, and long-term ecological consequences, particularly for biodegradable glitters. Addressing these gaps will require realistic exposure scenarios, mesocosm and field studies, and integrated chemical–biological approaches to support robust risk assessment and safer material design. Full article

Earthworm-derived bioactive compounds are emerging as promising pharmaceutical agents; however, the immunomodulatory effects of Eisenia fetida proteins at different developmental stages remain unclear. This study evaluated, for the first time, the stage-dependent immunomodulatory activity of E. fetida protein extracts in RAW 264.7 macrophages. Soluble proteins isolated from juvenile, mature, and senescent worms were lyophilized and tested for their effects on cell viability, phagocytic activity, nitric oxide (NO), reactive oxygen species (ROS), and inflammatory gene expression. Amino acid profiling and Western blot analysis were additionally performed to investigate biochemical composition and signaling mechanisms. Mature-stage extracts exhibited the highest protein yield, minimal cytotoxicity, enhanced macrophage phagocytosis, and significant suppression of LPS-induced NO, ROS, and proinflammatory cytokines. In contrast, juvenile-stage extracts showed moderate immunomodulatory activity, whereas senescent-stage extracts induced oxidative stress and inflammatory responses. Western blot analysis demonstrated that mature-stage proteins strongly inhibited phosphorylation of NF-κB and MAPK signaling proteins, including p65, IκBα, p38, ERK1/2, and JNK, while senescent-stage extracts maintained elevated pathway activation. Amino acid analysis further revealed enriched immunologically relevant amino acids in mature-stage extracts. These findings demonstrate that developmental stage strongly influences the biological activity of E. fetida proteins and highlight mature-stage extracts as promising natural immunomodulatory agents. Full article

Cadmium (Cd) accumulation in agricultural soils from prolonged phosphate fertilizer application threatens food safety in Southeast Asia, yet the combined performance of vermicompost (VC), biochar (BC), and Azolla microphylla for Cd immobilization remains poorly characterized. We evaluated their individual and combined effects in a Cd-spiked Korat soil (100 mg kg⁻¹ Cd as Cd(NO₃)₂) under controlled laboratory conditions. A completely randomized pot experiment with eight treatment combinations (four amendment regimes × two Azolla levels, n = 3) was incubated for five weeks; total and exchangeable Cd, selected soil properties, and Eisenia fetida growth were assessed before and after treatment. The combined of soil, cadmium vermicompost and biochar (SCVB) + Azolla treatment reduced total Cd by 41.13% and exchangeable Cd by 81.02%, significantly outperforming single amendments, while raising organic matter to 6.31% and nitrogen (N), phosphorus (P), and potassium (K) availability. Principal component analysis (PCA) explained >98% of the variance and separated SCVB clearly from the unamended control along soil-quality and Cd axes. Strong negative correlations between Cd and fertility indicators (r = −0.86 to −0.96) indicated coupled immobilization and fertility recovery. A 5-day acute earthworm bioassay confirmed reduced soil toxicity under SCVB + Azolla, with growth inhibition reduced from 55.9% to 23.6%, mortality reduced from 26.7% to 10%, and tissue Cd accumulation reduced from 44.08 to 25.17 mg kg⁻¹ (42.9% reduction). The integrated VC + BC + Azolla system offers a cost-effective amendment-assisted Cd immobilization strategy for tropical soils, pending field validation. Full article

Trans-cinnamaldehyde (CIN), the main component of cinnamon essential oil, is a promising sustainable alternative to synthetic pesticides. Despite its use, ecotoxicological data on non-target species remain fragmented. This study systematically evaluates CIN’s acute toxicity across multiple trophic levels to characterize the biological sensitivity and environmental response of key organisms. Aquatic assays measured bioluminescence inhibition in Aliivibrio fischeri and immobilization in Daphnia magna. Terrestrial evaluations included lethality tests on Eisenia fetida and root elongation in Allium cepa. Additionally, the impact on soil and river microbial communities was analyzed via Biolog EcoPlates™. Significant dose–response relationships were observed across all bioindicators (p < 0.0001). A. fischeri was the most sensitive species (EC₅₀ = 1.428 mg·L⁻¹), followed by D. magna (EC₅₀ = 4.533 mg·L⁻¹). In terrestrial models, A. cepa (EC₅₀ = 11.644 mg·L⁻¹) exhibited higher sensitivity than E. fetida (LC₅₀ = 412.519 mg·kg⁻¹). Microbial metabolic activity showed dose-dependent inhibition, particularly affecting carbohydrate and polymer degradation at high concentrations. These findings define the first ecotoxicological benchmarks for CIN, establishing EC₁₀ and EC₅₀ values under standardized conditions. These data provide the necessary toxicological constraints to ensure environmental safety in future field-scale applications of this natural compound. Full article

Sewage sludge management poses major environmental challenges due to increasing production and concerns about contaminants and microbial risks. Vermicomposting offers a sustainable biological treatment, yet the extent to which different earthworm species shape microbial outcomes remains poorly understood. Here, we examined how gut transit by three epigeic (Eisenia andrei, E. fetida, and Dendrobaena hortensis) and two anecic (Lumbricus friendi and L. terrestris) earthworm species alters bacterial and fungal communities in fresh sewage sludge. Using 16S rRNA and ITS amplicon sequencing combined with multivariate, differential-abundance, and functional prediction analyses, we compared sludge and earthworm cast bacteriomes and mycobiomes. Earthworm gut transit caused pronounced species-specific restructuring of bacterial and fungal community composition, diversity, and functional profiles, with clear separation between sludge and cast communities. Functional analyses indicated coordinated shifts in bacterial metabolic potential and fungal trophic modes consistent with enhanced biosynthetic and decomposer functions. Pathogen profiles were reshaped in a host-dependent manner, with low overall abundances and selective changes rather than uniform suppression. These findings demonstrate that vermicomposting outcomes depend strongly on earthworm species and microbial kingdom, highlighting the importance of earthworm lifestyle diversity when evaluating the ecological safety and agronomic potential of sludge-derived amendments. Full article

Integrated waste management through vermicomposting combined with biochar amendments represents an innovative approach for sustainable resource recovery. This study evaluated the effects of sugarcane bagasse biochar (SBB) at 0%, 5%, and 10% application rates on Eisenia fetida performance and vermicompost quality during preincubation-vermicomposting of sewage sludge and press-mud mixtures. The 10% SBB treatment significantly (p < 0.05) enhanced earthworm biomass (72.3% increase) and cocoon production (24.8 ± 1.8 per earthworm vs. 12.3 ± 1.2 in control). Lignocellulosic degradation improved substantially, achieving 22.6%, 10.7%, and 38.8% degradation for cellulose, hemicellulose, and lignin, respectively. Macronutrient concentrations increased significantly: TN by 38.4%, TP by 15%, and TK by 21.4% compared to initial mixtures. Moreover, total heavy metal concentrations decreased significantly during vermicomposting, with reductions of 8.1–8.7% for Pb, 5.3–7.6% for Cd, and 3.0–4.8% for Cr, with reduced bioavailability factors indicating enhanced metal stabilization. The final vermicompost exhibited optimal maturity indices, including a C:N ratio of 15.4 ± 0.2 and improved electrical conductivity. Results demonstrate that 10% sugarcane bagasse biochar amendment facilitates efficient concurrent management of sewage sludge and sugarcane industrial wastes while producing high-quality organic fertilizer with enhanced nutrient content, reduced heavy metal bioavailability, and accelerated stabilization for sustainable agricultural/horticultural applications. Full article

Almond hulls and shells are abundant by-products of the almond industry that could be valorized as bio-based absorbent polymers (BAP), offering a promising alternative to synthetic materials to improve water management in the agricultural setting. In this study, almond hulls and shells were pelletized in different proportions to assess pelletization feasibility and physical properties, followed by industrial-scale production of an industrialized formulation (80% hulls, 20% shells). Ecotoxicological risk was assessed using direct bioassays with whole pellets (germination with Lactuca sativa and Zea mays; acute toxicity with Eisenia fetida) and indirect bioassays with pellet water extracts (germination with L. sativa, immobilization with Daphnia magna, and bioluminescence inhibition with Vibrio fischeri). Field trials were conducted in an irrigated almond orchard to evaluate soil moisture dynamics and plant water status under different BAP application rates and irrigation regimes. Pelletization increased the soil’s water-holding capacity in the laboratory test and soil moisture in the field, even under reduced irrigation. However, ecotoxicological assays revealed significant to high acute toxicity at higher concentrations, depending on the organism and exposure pathway. Almond hull and shell pellets show potential to improve soil water retention and reduce irrigation demand but require cautious application and further testing to mitigate ecotoxicological risks. Full article