Search Results (178)

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 development of sustainable and efficient plant growth substrates is crucial for modern agriculture. This study assessed the potential of plant pellets formulated from various lignocellulosic residues, either with or without bamboo biochar (BB-char) and arbuscular mycorrhizal fungi (AMF), to support seed germination and early seedling growth. Four types of residues, including coconut coir (CO), corn cob (CC), leaves from the genus Dipterocarpus (DL), and teak leaves (TL), were combined with soil and paper waste to produce eight pellet formulations, with commercial peat pellets serving as a control. Chemical analyses revealed significant variation among the pellet types, with pH values ranging from 6.40 to 7.65, electrical conductivity (EC) from 3.64 to 11.62 mS cm⁻¹, and differences in organic matter, carbon, and nutrient contents [nitrogen (N), phosphorus (P), potassium (K)], reflecting the influence of residue type and the addition of BB-char and AMF. Phytotoxicity screening using aqueous extracts demonstrated species-specific responses, with cucumber exhibiting high tolerance across treatments, whereas chili seeds were more sensitive. Final germination percentage (FGP) and seedling growth assays in greenhouse conditions showed that pellets derived from CC and CO, particularly when combined with BB-char and AMF (T6 and T7), enhanced shoot and root development in carrot, chili, cucumber, and tomato, approaching the performance of commercial peat pellets. In contrast, DL- and TL-based pellets resulted in lower germination and growth. These findings indicate that both the physicochemical properties of lignocellulosic wastes and the combination of BB-char and AMF are important factors influencing pellet efficacy, highlighting the potential of CC- and CO-based pellets as sustainable peat alternatives for early-stage plant cultivation. 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

Propolis is a resinous bee product rich in bioactive compounds and widely recognized for its antimicrobial and antioxidant properties, but its effects on plants remain poorly explored, which could prove particularly relevant for applications in sustainable agriculture, namely in weed control. This in vitro study evaluated the phytotoxicity of propolis extracts obtained from materials considered waste, aiming for their valorization as natural bioherbicides. Two hydroalcoholic extracts produced from raw propolis—mPN.EE₇₀ (from mixed leftover samples) and Cr18.EE₇₀ (from a sample rejected by the pharmaceutical industry)—and one aqueous extract (RE23.WE) obtained from the residues of a previous ethanolic extraction were analyzed. All extracts exhibited antioxidant activity (DPPH assay), with mPN.EE₇₀ showing the lowest EC50 and RE23.WE the highest. Significant differences were observed in total phenolic and flavonoid contents, with Cr18.EE₇₀ presenting the highest values and RE23.WE the lowest. In vitro germination and early growth assays revealed pronounced species-, extract- and dose-dependent effects. White mustard (Sinapis alba) and lettuce (Lactuca sativa) were particularly sensitive to RE23.WE, which severely inhibited root growth. Interestingly, the spontaneous weeds Plantago lanceolata and Dactylis glomerata were sensitive to all the extracts, P. lanceolata being the most sensitive of all species. This species was particularly affected in root growth by mPN.EE₇₀, and in epicotyl development by Cr18.EE₇₀. Dactylis glomerata was specifically root-responsive, where RE23.WE, like in P. lanceolata, was the only extract causing significant inhibitions in both root and leaf growth at all concentrations. Although experiments at larger scales are needed for validation before agricultural applications, overall these findings demonstrate the potential of unused propolis samples and extraction residues as a source of bioherbicides for a more sustainable and circular agriculture. In particular, the remarkable effectiveness of the aqueous extract RE23.WE against all tested species promises an effective, environmentally safer, less costly, and therefore more economically viable approach for a weed control strategy. Full article

This study evaluated the phytoremediation potential of the halophytic plant Sesuvium portulacastrum (L.) L. for treating industrial wastewater (IWW) in a hydroponic system over a nine-day exposure period. After treatment, the physicochemical analysis of IWW revealed a significant decrease in chemical oxygen demand (COD), biological oxygen demand (BOD), TSs (total solids), total dissolved solids (TDSs), TSSs (total suspended solids), ammonia, phosphate, and nitrate. The COD and BOD were reduced by 90.7% and 82.9%, respectively. The metal analysis indicated a significant decrease in Fe (95%), Mn (87.4%), and Al (93.9%) and complete removal of Ni, Pd, and Zn. The plant stress responses were assessed through the estimation of photosynthetic pigments (Chlorophyll-a, Chlorophyll-b, Total chlorophyll), phenolic and flavonoid contents, and antioxidant activity. Total chlorophyll declined from 1.449 mg/g (control) to 1.20 mg/g on Day 3, followed by partial recovery to 1.25 mg/g by Day 9, indicating physiological acclimatization. Total phenolic content reached 14 mg GAE/g in leaves and 12 mg GAE/g in stems on Day 6, while Total flavonoid content increased from ~70 µg/g (control) to 115 µg/g on in leaves. The metabolic profiling using GC-MS/MS revealed distinct time- and tissue-specific metabolic responses, with 53 metabolites identified in roots and 62 metabolites in leaves. The major differentially accumulated metabolites were sucrose, pinitol, talose and psicose, with peak accumulation at Day 6. A biphasic metabolic response pattern, characterized by early stress perception followed by adaptability, was observed. Phytotoxicity assays using Vigna radiata demonstrated improved germination from 15% (untreated IWW) to 95% after treatment. Overall, the study highlights the strong phytoremediation potential of halophyte S. portulacastrum as an environmentally friendly alternative for industrial wastewater remediation. Full article

Chitosan-based silver nanoparticles (Ch-AgNPs) are emerging as promising antimicrobial materials with potential applications in crop protection. This study evaluated the formulation-dependent antimicrobial activity and plant compatibility of Ch-AgNPs synthesized from chitosan extracted via different routes from shrimp shells. Antibacterial activity was assessed against representative Gram-negative and Gram-positive model bacteria (Escherichia coli and Staphylococcus aureus), as well as phytopathogenic bacteria (Xanthomonas campestris, Pseudomonas syringae), using disk diffusion assays. Antifungal activity was evaluated against Fusarium graminearum in vitro and in a controlled growth chamber. All formulations exhibited concentration-dependent antibacterial activity, with L10 and L20 formulations derived from optimized lactic acid-based extraction routes and DP4 derived from an inorganic deproteinization-based extraction route showing the highest efficacy at 1.0 mg/mL. Strong antifungal activity was observed, particularly for L10 and DP4, achieving mycelial growth inhibition of 92% and 84%, respectively, at 1.0 mg/mL. Seed germination and seedling growth assays confirmed that all formulations were non-phytotoxic at 1.0 mg/mL, with L10 and DP4 significantly enhancing germination parameters and early plant growth. Under controlled conditions, these formulations also reduced the incidence and severity of crown and root rot in spring wheat caused by F. graminearum. These findings demonstrate that optimized Ch-AgNP formulations combine antimicrobial activity with plant compatibility, highlighting their potential for crop protection, pending further environmental safety and agronomic validation under field conditions. Full article

Moko disease (Ralstonia solanacearum race 2) is one of the most destructive bacterial diseases affecting bananas and plantains worldwide. The pathogen infects banana plants, causing yellowing and wilting of younger leaves, and plant death. Disease management remains challenging due to the pathogen’s aggressiveness, rapid dissemination, and limited availability of effective control products. The aim of this study was to determine the chemical composition of the Pimenta dioica essential oil (PDEO) obtained by hydro-distillation and to evaluate its antibacterial activity against R. solanacearum race 2. Gas chromatography-mass spectrometry (GC-MS) analysis identified 19 compounds in the essential oil. Eugenol (72.6%), was the predominant component, followed by caryophyllene (6.13%) and Beta-Myrcene (4.17%). In vitro assays demonstrated complete inhibition of bacterial growth at 500 µL L⁻¹. Probit analysis estimated the minimum inhibitory concentration 95% (MIC₉₅) value 297.6 µL L⁻¹. In plants evaluation using banana vitroplants showed that PDEO at 500 µL L⁻¹ effectively reduced disease severity and prevented internal corm discoloration without causing phytotoxic effects. These findings demonstrate the strong antibacterial activity of P. dioica essential oil against R. solanacearum race 2 and highlight its potential as a natural alternative for the management of Moko disease in banana production systems. Full article

This study addresses the need for sustainable approaches in textile wastewater treatment by investigating laccase production with the white-rot fungus Schizophyllum commune TMF3 using agro-industrial waste as a substrate. Laccase was produced via solid-state fermentation on brewery spent grain under optimized conditions (1.75 g malt extract, 75% moisture, 7 days, 25 °C), reaching a maximum activity of 21.06 IU/g dry substrate. The crude enzyme was applied for the decolorization of azo and triphenylmethane dyes (50 mg/L). Decolorization efficiencies above 80% were achieved within 60 min without redox mediators, while chemical oxygen demand (COD) was reduced by more than 50% for all tested dyes. HPLC analysis showed parent dye peaks decreasing and the transformation products’ appearance. Antimicrobial activity testing showed no increase in inhibitory effects against Escherichia coli, Lactobacillus rhamnosus, Candida albicans, and Saccharomyces cerevisiae, while slight growth stimulation was observed in selected cases. Phytotoxicity assays using Triticum aestivum showed no inhibitory effects, with germination index values of 77–124%. Cytotoxicity assessment showed no effects for azo dyes, while cytotoxicity of the triphenylmethane dye decreased by 30% after treatment. These findings support the potential of agro-industrial laccase production as an effective approach for dye removal in sustainable wastewater strategies. Full article

Azo dyes demonstrate dose-dependent carcinogenic and mutagenic effects in exposed cells. Among remediation approaches, microbial adsorption is the most sustainable and environmentally friendly method for eliminating azo dyes. A novel Aspergillus terreus silica composite was developed as a sustainable adsorbent for crystal violet dye (CVD) removal. The fungal strain was isolated from dye wastewater and was genetically identified by 18S rRNA gene sequencing. Dried mycelia of A. terreus (PX920301) were combined with SiO₂ (1:1 w/w) through iterative hydration-drying cycles, yielding a composite characterized by FTIR analyses. Removal CVD %, adsorption capacity, and CVD residual were calculated, and the adsorption process was optimized using Box–Behnken design (four factors, 25 runs). The biosafety of the composite was assessed for phytotoxicity and microbial toxicity. The composite was also applied to real dyes wastewater collected from the bacteriological laboratory. Aspergillus terreus-silica composite showed the highest CVD removal percentage by 85.4%, adsorption capacity (qe) 121.1 mg/L, and lowest CVD residual by 7.26 mg/L, followed by the dried active mycelia (DA-mycelia) with CVD removal 40.23%, adsorption capacity (qe) 57.05 mg/L, and CVD residual by 29.73 mg/L. Optimization data cleared that the maximum experimental values of CVD removal (%) was 99.59% (predicted value 100%) obtained in run number (4) using initial CVD concentration (200 mg/L), pH (8), adsorbent composite weight (0.1 g), and contact time (48 h). Biosafety evaluation demonstrated negligible phytotoxicity against Triticum aestivum seedlings post-treatment, with restored germination and growth comparable to controls. Microbial toxicity assays via well-diffusion to seven microbial isolates confirmed no toxic activities against the tested bacteria, yeast, and fungi, underscoring the composite’s environmental safety. The composite could decolorize the real dye wastewater of laboratories by 95.37%. In conclusion, A. terreus mycelial-silica composite offers a cost-effective, sustainable, and eco-friendly alternative solution for dye bioremediation. Full article

Fungal pathogens pose a major threat to global agriculture and human health, necessitating alternative antifungal strategies with high efficacy and low resistance potential. Antifungal proteins (AFPs) from filamentous fungi are promising candidates due to their stability, selectivity, and diverse mechanisms of action. Here, we characterize Beauveria brongniartii antifungal protein (BbroAFP), a novel cysteine-rich protein from the entomopathogenic fungus B. brongniartii, and investigate its antifungal activity against Botrytis cinerea. Recombinant BbroAFP was expressed in Pichia pastoris, purified, and verified by liquid chromatography–tandem mass spectroscopy (LC–MS/MS) and in silico modeling. BbroAFP showed potent antifungal activity with minimum inhibitory concentrations (MICs) as low as 1 µM against several phytopathogenic fungi, while exhibiting no significant antibacterial activity. Activity was maintained across a wide range of pH and temperature conditions. Confocal microscopy revealed rapid surface binding followed by cytosolic internalization without major cell wall disruption. BbroAFP induced a rapid, transient burst of reactive oxygen species (ROS), accompanied by nuclear DNA fragmentation. Gene expression analysis revealed a transient increase in aif1, whereas mca1 expression decreased at later time points and mca2 remained largely unchanged, suggesting a metacaspase-independent response. Detached tomato leaf assays showed effective protection against B. cinerea without detectable phytotoxicity. Cytotoxicity assays confirmed a favorable safety profile, supporting further evaluation of BbroAFP for plant protection. Full article

This study investigated the effects of aqueous extracts of orange peel–derived biochar on seed germination and early seedling growth in durum wheat (Triticum durum Desf.) and common buckwheat (Fagopyrum esculentum Moench.). Biochar was produced by pyrolysis of orange peel at temperatures ranging from 250 to 550 °C. Germination assays were conducted under controlled laboratory conditions, and seedling growth parameters were evaluated after six days of cultivation. Untreated orange peel completely inhibited seed germination (0 %) in both species, while biochar produced at 250 °C significantly reduced germination (e.g., the germination index decreased from 54.21 % in the control to 47.2 % in T. durum). In contrast, biochar produced at 350 °C increased germination to >96 % in T. durum and 100 % in F. esculentum, accompanied by enhanced seedling vigor and biomass production. Chemical analyses revealed a pronounced decrease in total phenolic content (from 53.84 to 0.57 mg GAE g⁻¹ DW) and flavonoids (from 90.05 to 1.34 mg QE g⁻¹ DW) with increasing pyrolysis temperature, along with a reduction in antioxidant activity. Common buckwheat exhibited consistently higher tolerance to biochar extracts than durum wheat across all treatments. Overall, the results demonstrate that pyrolysis temperature is a key factor governing the transition from phytotoxic to biostimulatory effects, with optimal performance observed at approximately 350 °C. Full article

Chitosan nanoparticles (Ch NPs) are versatile nanomaterials with expanding agricultural and biomedical applications, highlighting the need for reproducible, low-cost, and scalable synthesis methods to ensure their safe and widespread use in biological systems. This study presents a simple ionic-gelation protocol using a serological pipette–needle dropwise system that minimizes reagent waste and requires no sophisticated equipment. The synthesized Ch NPs were characterized by UV–Vis spectroscopy, ESEM, TEM, EDS, DLS, XRD, and FTIR, confirming nanoscale size, strong positive surface charge, and characteristic chitosan–TPP interactions. To establish a standardized biological safety assessment framework, three representative bioassays were implemented across microbial, plant, and mammalian systems. Antibacterial testing against Xanthomonas oryzae pv. oryzae (Xoo) using a resazurin-based microdilution assay revealed a minimum inhibitory concentration (MIC) of 128 µg/mL, whereas bulk chitosan showed no inhibition up to 512 µg/mL. Phytotoxicity and seed germination assays on rice (Oryza ‘KDML105’) demonstrated no inhibitory effects on germination, with over 90% germination by day 3 and significantly enhanced seedling growth parameters (p < 0.05) at 64–128 µg/mL, indicating non-phytotoxicity. MTT assays confirmed that Ch NPs were non-toxic to both human skin cell lines (HDF and HaCaT) across 2.5–160 µg/mL, showing enhanced cell viability in HDF cells at specific concentrations and stable viability in HaCaT cells, indicating overall biocompatibility. Importantly, all bioassays were conducted under aligned concentration ranges to enable cross-system comparison and reproducibility. This integrated workflow links nanoparticle synthesis with a standardized, multi-system evaluation strategy, supporting the safe application of Ch NPs in biological systems. Full article

Pruning residues from medicinal and aromatic plant cultivations represent an under-exploited biomass rich in bioactive metabolites. In this study, pruning by-products from Lavandula angustifolia Mill. ‘Essence Purple’ and Helichrysum italicum (Roth) G.Don were investigated as sources of essential oils (EOs) within a circular economy perspective. Micromorphological analyses confirmed the presence of secretory glandular trichomes in the residual biomass. EOs were obtained by steam distillation (0.33% and 0.15% yield for lavender and helichrysum, respectively) and chemically characterized by GC-FID and GC-MS. A total of 51 and 55 compounds were identified, accounting for 99.68% and 99.57% of the total composition. The main constituents were τ-cadinol (23.09%) and linalyl acetate (14.07%) in lavender EO and γ-curcumene (15.47%) and eudesm-4(14)-en-11-ol (10.71%) in helichrysum EO. Pruning-derived EOs showed a higher sesquiterpene content than those from conventional plant organs, indicating a compositional shift. Phytotoxic assays on Hordeum vulgare, Raphanus sativus, Lolium multiflorum, and Sinapis alba revealed concentration-dependent effects, with a stronger inhibition of radicle elongation than seed germination. These concentrations should be interpreted as indicative of intrinsic phytotoxic potential under controlled conditions. Ecotoxicological tests showed no significant reduction in viability in Artemia salina, whereas concentration- and time-dependent immobilization was observed in Daphnia magna, highlighting species-specific sensitivity, likely related to differences in the uptake and membrane interactions of lipophilic compounds. These findings highlight pruning residues as a promising biomass for the recovery of bioactive phytocomplexes with potential applications in sustainable weed management, although further studies under agronomically relevant conditions and comprehensive environmental assessments are required to validate their practical applicability. Full article

The textile industry wastewater contaminated by azo dyes usually contains a certain amount of salinity. Therefore, screening for microorganisms capable of degrading azo dyes in saline environments is of great significance. In this study, the decolorizing activity of azo dye methyl red (MR) by Klebsiella aerogenes WH2 (WH2), newly isolated from soil, was evaluated. WH2 was able to decolorize 92.4% and 86.0% of MR at concentrations of 200 mg/L and 300 mg/L within 24 h, respectively. Given that WH2 exhibited enhanced growth and superior degradation capacity in the presence of 2.5% NaCl compared to salt-free conditions, it can be classified as a slight halophile. Approximately 87.7% of MR was removed by WH2 in the presence of 10.0% NaCl within 24 h. Azoreductase activity assays indicated that WH2 retained higher enzyme activity in the presence of NaCl concentrations not exceeding 7.5%. The degradation products and putative metabolic pathways for MR degradation by WH2 were analyzed using FTIR and LC-MS. Phytotoxicity analysis based on seed germination of Vigna radiata indicated that the degradation products of MR exhibited less toxicity than the parent compound. The high degradation efficiency of MR under high salt concentrations makes WH2 a promising candidate for the treatment of saline textile wastewater. Full article

Fungal diseases represent one of the major threats to citrus production, such as anthracnose caused by Colletotrichum gloeosporioides and Fungal Trunk Diseases (FTDs) associated with Botryosphaeriaceae, with Neofusicoccum parvum being the most prevalent species. In response to the need to reduce chemical fungicide use, this study evaluated the antifungal activity of essential oil-based nanoemulsions (N-EOs) as alternative management methods. Seven N-EOs (citronella, clove, fennel, garlic, laurel, lavender and peppermint) were first screened in vitro against multiple isolates of both pathogens through mycelial growth and conidial germination assays. Based on estimated EC₅₀ and EC₉₀ values, clove and garlic N-EOs exhibited the highest inhibitory activity, while lavender displayed intermediate but promising efficacy, particularly against N. parvum. These N-EOs were subsequently evaluated in vivo on lemon fruits inoculated with C. gloeosporioides and on detached lemon twigs inoculated with N. parvum. In vivo assays largely confirmed the in vitro trends, with clove and garlic significantly reducing lesion development. In contrast, lavender displayed limited efficacy under in vivo conditions. The phytotoxic effects at higher concentrations limited the range of applicable doses. Overall, the results suggest that N-EOs, particularly those based on clove and garlic, may offer potential as alternative tools for citrus disease management. However, host tissue interactions, formulation stability, volatility, and validation under field conditions remain critical aspects requiring further investigation. Full article