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Journal of Hazardous Materials

Elsevier BV

Preprints posted in the last 90 days, ranked by how well they match Journal of Hazardous Materials's content profile, based on 21 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Organic Germanium (Ge-132) reduces glycative damage while maintaining cellular stress signaling: evidence of functional dissociation

Ponce Mora, A.; Fauzi El-Adhiri, Y.; Guillamin, G.; Martell Vergara, A.; Locascio, A.

2026-04-24 molecular biology 10.64898/2026.04.22.720084 medRxiv
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Organic germanium, particularly carboxyethyl germanium sesquioxide (Ge-132), has been investigated for decades in relation to diverse biological effects, with a strong emphasis on its antioxidant properties. However, the available literature remains dispersed, encompassing heterogeneous experimental models and endpoints that limit mechanistic interpretation. While antiglycative activity has been described at the biochemical level, its downstream gene regulatory consequences under glycative stress remain inconsistently characterized. Here, we combined systematic review of the literature of experimental studies with targeted molecular analysis in a standardized cellular model. The literature mapping was used to guide pathway selection rather than to establish quantitative associations. Based on patterns emerging from literature, we focused on pathways associated with glycative stress responses, including carbonyl stress, inflammatory signaling, and autophagy regulation. Gene expression analysis revealed a limited and selective modulation of regulatory pathways under glycative stress conditions, consistent with a context-dependent effect rather than broad transcriptional reprogramming. In parallel, protein analysis showed reduced intracellular accumulation of advanced glycation end products (AGEs) in Ge-132-treated cells under glycative stress conditions. Importantly, these findings support a dissociation between glycative damage reduction and cellular stress-response pathways. This combined approach helps interpretation of previously fragmented observations across the literature and highlights gene regulation under glycative stress as a relevant but still unresolved aspect of organogermanium biology.

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Environmentally relevant depleted uranium exposure damages mitochondria, decreases cytosolic reductive capacity, and increases global DNA damage accumulation through a ROS-independent mechanism involving slingshot protein phosphatase 1b enrichment.

Kalaniopio, P. H.; Gibbons, L. B.; Allen, R. S.; Matthews, S. M.; Lujan, O. R.; Gaaloul, E.; Wilbanks, J.; Allen, C. M.; Chassman, C. A.; Traustadottir, T.; Propper, C. R.; Salanga, M. C.

2026-07-08 pharmacology and toxicology 10.64898/2026.07.02.736169 medRxiv
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Depleted uranium (DU) is an environmental contaminant with a 30 g/L (ppb; parts per billion) EPA maximum contaminant level (MCL) for drinking water. The mining of uranium and use of DU in modern weapons underly human exposure that disproportionally impacts military and tribal communities in the United States. Uranium's radiotoxic characteristics are understood, but its chemical hazards much less so. In zebrafish (Danio rerio) and human cell cultures we test the hypothesis that exposure to DU negatively impacts cellular function and development through disruption of mitochondrial metabolism. Using a novel shrapnel model with TEM/SEM+EDS, we showed uranium microparticles caused proximity-dependent mitochondrial disruption. In waterborne exposure paradigms, larval movement was reduced and hatching delayed as a result of reduced movement and not enzyme deficiencies in response to 18 ppb DU, below the MCL. Increased DNA damage accumulation was detected in exposed larva and cells. DNA-damage quantitative PCR of DU-exposed larvae showed increased damage in the ahr1 locus (nuclear gene) and decreased mitochondrial DNA (mtDNA) copy number, but mtDNA damage levels varied across experiments. Mitochondrial function was assessed using a resazurin-based assay in the presence and absence of antioxidants and showed diminished cytoplasmic reductive capacity. DU exposure alone did not enrich antioxidant gene expression, contrasting with arsenic exposure, a known ROS-inducer and Nrf2-activator. Sulforaphane (SFN), a potent Nrf2-activator, did not blunt the effects of DU exposure, despite activation of antioxidant response element (ARE) genes (gstp and gss), but did blunt the effects of arsenic exposure. The most enriched transcript in DU-exposed larvae coded for slingshot protein phosphatase (ssh), further exploration revealed ssh1b as the zebrafish-specific ortholog activated in response to DU, and inhibition using an identified SSH1 inhibitor, Sennoside A, partially rescued the metabolic and hatching defects observed. Our data points to a cytotoxic mechanism in which DU disrupts mitochondrial function through ssh1b enrichment that impairs normal mitophagy, leading to decreased cellular reductive potential independent of either ROS production or ARE-activation. Our results suggest that health impacts from DU exposure may be directly linked to impaired mitochondrial functions.

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Nickel-Driven Dynamics of Urease in Sporosarcina pasteurii: Integrated Computational and Experimental Insights

Al-Thawadi, S. M.

2026-06-19 bioinformatics 10.64898/2026.06.15.732323 medRxiv
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Urease is a nickel-dependent enzyme that plays an important role in urea hydrolysis and in a process named as microbial-induced calcium carbonate precipitation (MICP), which is widely used in sustainable environmental biotechnology. Despite its ecological importance, urease powers Biogrout (biocementation), a promising green technology for soil stabilization and infrastructure repair. Yet, the relationship between nickel availability, enzyme activation, and bacterial fitness remains poorly understood. In this study, we reveal a striking dual effect of nickel on Sporosarcina pasteurii: while high Ni{superscript 2} concentrations strongly inhibit growth (IC {approx} 637.7 {micro}M), they simultaneously boost specific urease activity up to six-fold. This uncoupling between biomass and enzymatic efficiency highlights a previously overlooked adaptive strategy under metal stress. Using structural bioinformatics and molecular docking, we show that Ure1--the catalytic subunit--exhibits the strongest nickel affinity (-4.3 kcal{middle dot}mol-{superscript 1}), supported by highly conserved active-site residues, whereas accessory proteins UreE and UreG display moderate and weak binding, consistent with their roles in metal delivery and GTP-dependent maturation. In addition, microscopic observations confirmed that calcium carbonate precipitation was most pronounced at intermediate nickel concentrations (approximately 400-1000 {micro}M), whereas higher concentrations ([≥]1000-1300 {micro}M) led to reduced mineral formation due to loss viable cells. Taken together, these results indicates that nickel availability controls both urease activation and bacterial fitness, and that an optimal balance is required to maximize biomenerilization efficiency in environmental applications, particularly in biocementation technology. ImportanceUrease-driven biomineralization is widely used in sustainable technologies such as soil stabilization and self-healing concrete. However, optimizing these systems requires a clear understanding of how environmental factors influence enzyme performance. This study shows that nickel, an essential cofactor for urease, plays a dual role by enhancing enzymatic activity while inhibiting bacterial growth at high concentrations. By integrating experimental data with computational analysis, we demonstrate that efficient biomineralization depends on maintaining nickel within an optimal range that balances enzyme activation and microbial viability. These findings provide practical guidance for improving biocementation processes and highlight nickel as a key regulator of urease-based environmental biotechnology applications.

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A Two-Arm Metabolic-Efflux Adaptation Framework in Klebsiella pneumoniae under Mixed Pharmaceutical Exposure: rutA-Linked Oxidative Entry and rutR-Associated Regulation

Sinha, S.; Barman, P.; Haldar, D.; Chakraborty, R.

2026-07-13 microbiology 10.64898/2026.07.11.738005 medRxiv
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Chemically complex pharmaceutical mixtures in wastewater and sludge can affect microbial adaptation; however, the responses to different co-occurring compounds have not been elucidated well. In this study, the adaptation of a strain derived from hospital sludge, Klebsiella pneumoniae SS02, to 17-ethinylestradiol (EE2), warfarin sodium, and their combination has been studied. The organism grows under all three conditions, and pre-exposure experiments show induction and cross-induction to substrates. UHPLC MS/MS analyses demonstrated that there is conditional depletion of the parent compound EE2 by [~]15% at 36 h post-treatment compared to initial concentrations, but not for the abiotic and non-adapted controls. The rate of warfarin sodium depletion was approximately [~]30% within 36 h and was in accordance with first order kinetics (k = 0.0102 /h; t{square}/{square}= 67.9 h). Under the combined treatment regime, there was a delay in warfarin sodium depletion, suggesting staged substrate consumption. Growth inhibition with efflux inhibitors confirmed transport-driven tolerance. A genome-based study revealed the coordinated response strategy that involved a proposed flavin-dependent monooxygenase (RutA), an oxidative entry into the pathway; redox processing linked to Hpa; aromatic metabolism through {beta}-ketoadipate pathway; and RND efflux system. The structural study additionally supported ligand-mediated decrease in DNA binding affinity of RutR, which is in agreement with de-repression of the substrate-activated regulatory mechanism. All these findings lead to the development of a dual-strategy for adaptation model in which oxidative modification and efflux-mediated protection work together under the influence of a mixture of pharmaceuticals.

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Do nanoplastics reshape microglial support of neuronal resilience? A study of microglial bioenergetics and microglia to neuron communication in vitro

Brunialti, E.; Meda, C.; Villa, A.; Parolini, M.; Ciana, P.; Casati, L.

2026-06-25 pharmacology and toxicology 10.64898/2026.06.17.732827 medRxiv
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Nanoplastics (NPs) are emerging environmental contaminants able to cross biological barriers, disrupt cellular and organelle homeostasis, and alter the brain microenvironment. This study investigated whether NPs affect microglia to neuron communication, a key mechanism underlying neuronal resilience, via the nuclear factor erythroid 2 like 2 (NFE2L2) pathway. Using an in vitro model, we evaluated the effects of polystyrene nanoplastics on microglial metabolic fitness and microglia-mediated neuronal stress responses. Increasing NP concentrations induced a dose dependent biphasic effect. Low to intermediate concentrations increased intracellular adenosine triphosphate (ATP) levels in microglia and enhanced microglia-mediated activation of neuronal NFE2L2. In contrast, high NP concentration impaired microglial metabolism, reduced ATP availability, and decreased microglia to neuron communication. These findings indicate that NPs alter microglial energetic status and modulate neuroprotective signalling, potentially contributing to impaired neuron to microglia interactions and increased susceptibility to neurotoxicity.

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Polystyrene microplastics uptake drives Inflammatory, Epitranscriptomic, and Metabolic Reprogramming in Human aortic endothelial cells

Khan, A.; Koher, G.; Khan, T.; Grant, K.; Zheng, G.; Young Lee, H.; S. Vidar, W.; Morales-Shnaider, F.; Chen, J.; A. Darfour-Oduro, K.; Bhandari, R.; Zhu, X.; Wu, K.; Chiu, N.; Jia, Z.

2026-07-10 molecular biology 10.64898/2026.07.09.737624 medRxiv
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Microplastics are pervasive environmental pollutants increasingly implicated in adverse human health effects, with emerging evidence linking MPLs exposure to elevated cardiovascular risk, including atherosclerosis. However, their specific mechanisms of action remain unknown. Human aortic endothelial cells (HAECs), located in the innermost layer of blood vessels, play a crucial role in maintaining vascular homeostasis and the development of atherosclerosis. This study demonstrates that polystyrene microplastics (80 nm MPLs) can enter HAECs through multiple pathways, including macropinocytosis, clathrin-mediated endocytosis, and caveolin-mediated endocytosis, and co-localize with mitochondria and lysosomes. MPLs exposure resulted in coordinated transcriptional, epitranscriptomic, and metabolomic reprogramming in HAECs, characterized by disruption of mitochondrial genes and an inflammatory response with activation of TNF-a; and NF-kB signaling. Integrative analysis revealed remodeling of the epitranscriptomic profile, demonstrated by an increase in 1-methyladenosine (m1A) modification along with reciprocal regulation (TRMT61A upregulation and ALKBH3 suppression) of its transcriptomic machinery, alongside other enzymes associated with 3-methylcytidine (m3C), pseudouridine (Y), 5-methylcytidine (m5C), and 7-methylguanosine (m7G) pathways. By comparing transcriptomic data from MPLs-treated HAECs with those of human atherosclerotic plaques, several common dysregulated pathways were identified, particularly those related to vascular physiological regulation and cell signaling. Metabolomic profiling further revealed significant remodeling of lipid metabolic networks associated with oxidative stress and inflammatory signaling. In summary, this study reveals that HAECs can internalize MPLs, leading to multiple disturbances in the transcriptome, epigenome, and metabolic networks, suggesting that MPLs exposure may pose a potential hazard to human cardiovascular health.

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Integrative computational toxicology reveals PFOS and PFHxS associated inflammatory keratinocyte niches in psoriasis through exposure transcriptomics, single-cell spatial mapping and token-aware virtual perturbation

Ma, J.; Yu, Q.

2026-07-15 bioinformatics 10.64898/2026.07.09.737426 medRxiv
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Per- and polyfluoroalkyl substances (PFAS) are persistent toxicants with immunological, metabolic and epithelial effects, but their relevance to inflammatory skin disease remains unclear. We developed a computational toxicology framework to test whether perfluoroalkyl sulfonate programs, especially perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS), converge with psoriasis-associated keratinocyte inflammation. Exposure transcriptomes were derived from GSE236956, in which human embryonic stem cell-derived epithelial-lineage models were exposed to 10 M PFAS for 8-16 days. Six PFAS were prioritized using descriptors, Tanimoto similarity, toxicology evidence, adverse outcome pathway (AOP)-like key events, exposure differentially expressed gene burden and read-across support. PFAS signatures were integrated with psoriasis bulk transcriptomes, single-cell RNA sequencing, keratinocyte-state mapping, regulator and communication inference, spatial transcriptomics and token-aware Geneformer-compatible virtual perturbation. PFOS ranked highest in integrated prioritization, followed by PFHxS and perfluorooctanoic acid. PFHxS produced a smaller but directionally informative signature within a PFOS-dominant perfluoroalkyl sulfonate footprint. The shared PFOS and PFHxS program converged with psoriasis through inflammatory keratinocyte, epidermal-stress, cytoskeletal and lipid-related modules. Single-cell and spatial analyses localized the program to activated keratinocytes and inflammatory epidermal niches, with strong spatial co-localization with inflammatory keratinocyte and epidermal stress scores. Virtual perturbation prioritized S100A9, S100A8, KRT16, IL36G, CCL20, CXCL8, FABP5, KRT17, FOS, JUN and NFKBIZ as candidate effectors. These findings support an exposure-informed, experimentally testable hypothesis linking persistent perfluoroalkyl sulfonate programs to keratinocyte inflammatory niches in psoriasis.

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Bidirectional interactions between gut microbiota and fluorochemical biotransformation and bioactivity

Stevanoska, M.; Pena-Diaz, J.; Bieler, M.; Fernandez Cereijo, R.; Gaechter, L.; Probst, S. I.; Sokolova, N.; Robinson, S.; Bokulich, N. L.; Sturla, S. J.; Aichinger, G.

2026-05-19 pharmacology and toxicology 10.64898/2026.05.15.725488 medRxiv
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Fluorinated chemicals are increasingly prevalent in pharmaceuticals and agrochemicals, yet their influence on the human gut microbiome and the potential for microbial biotransformation to alter therapeutic and toxicological profiles remain poorly understood. Here, we investigated the bidirectional relationship between 15 structurally diverse fluorinated chemicals and the gut microbiota by using an ex vivo high-throughput fermentation system. Screening revealed that flutamide, fluazinam, and pretomanid were consistently biotransformed across the donor microbiomes, while other compounds showed substantial inter-individual variability in degradation. Furthermore, exposure to fluorinated chemicals induced compound-specific shifts in microbial diversity and community composition, demonstrating their capacity to alter gut microbial ecology. Using a computational workflow combining in silico biotransformation predictions with untargeted LC-MS/MS analysis, we identified nitroreduction as the primary gut microbial transformation across all three compounds. Single-strain experiments confirmed that the nitroreduction of flutamide to flu-6, previously attributed only to hepatic metabolism, is a widespread capacity among gut bacterial strains. Finally, in vitro cytotoxicity assays and in silico modelling further revealed flu-6 to be a less hepatotoxic derivative than the parent compound, suggesting a potential detoxifying role for the gut microbiota. Together, these findings establish an integrated ex vivo, in vitro, and in silico approach for assessing the bidirectional interactions between fluorinated chemicals and the gut microbiome.

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Drosophila melanogaster as a platform for the functional expression of engineered PET-degrading enzymes

Pirillo, V.; Barca, F.; Bruno, D.; Caramella, S.; Fontana, C.; Battistolli, M.; Catelan-Carphio, E.; Roma, D.; Casartelli, M.; Caccia, S.; Grapputo, A.; Tettamanti, G.; Molla, G.; Sandrelli, F.

2026-06-09 biochemistry 10.64898/2026.06.04.729872 medRxiv
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Insects offer promising opportunities for organic waste bioconversion; however, they cannot efficiently degrade synthetic polymers such as polyethylene terephthalate (PET). Here, we generated transgenic Drosophila melanogaster lines to express in vitro-evolved variants of two PET-degrading enzymes with distinct biochemical properties: an engineered Ideonella sakaiensis PETase variant (TS-{Delta}IsPET) and a leaf-branch compost cutinase variant (TA-{Delta}LCC). Both enzymes, fused to a Drosophila gut-derived secretory signal, were produced and secreted by both Drosophila cultured S2R+ cells and transgenic larvae. Both enzymes were glycosylated upon secretion, a post-translational modification that did not abolish their catalytic activity. Notably, TA-{Delta}LCC displayed [~]6-fold higher esterase activity than TS-{Delta}IsPET in larval extracts and TA-{Delta}LCC-containing extracts depolymerised PET nanoparticles in vitro under enzyme-favourable conditions. Transgenic flies showed normal development, fertility and survival. Morphological and biochemical analysis confirmed that TA-{Delta}LCC expression did not alter midgut structure and function. Together, these results establish Drosophila melanogaster as a model for functional expression and comparative evaluation of engineered PET-degrading enzymes and identify TA-{Delta}LCC as a promising candidate for exploitation in insect species relevant to plastic contaminated waste bioconversion. HighlightsO_LITransgenic D. melanogaster enables in vivo study of engineered PET enzymes C_LIO_LIEngineered TS-{Delta}IsPET and TA-{Delta}LCC are functional in larval extracts C_LIO_LITA-{Delta}LCC was selected for PET nanoparticle assays due to higher pNPA activity C_LIO_LID. melanogaster model enables comparative evaluation of PET-degrading enzymes C_LI

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Phosphorus-laden Mg/Fe Layered Double Hydroxide Dispersed on Douglas fir Biochar as a Controlled Release Fertilizer and its effect on the growth of bush beans (Phaseolus vurlagris).

Singh, T.; Rodrigo, P. M.; Folk, R. A.; Dhillon, J.; Varco, J. J.; Mlsna, T.

2026-05-23 plant biology 10.64898/2026.05.22.727001 medRxiv
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Many agricultural soils are deficient in key macronutrients needed for healthy plant development. Relying on highly water-soluble commercial fertilizers for long durations can be costly and environmentally harmful. This study investigates a phosphorus-loaded Mg/Fe layered double hydroxide (LDH) dispersed on Douglas fir biochar (Mg/Fe-LDH biochar) as a controlled-release fertilizer and evaluates its impact on bush bean (Phaseolus vulgaris L.) growth. Emphasizing sustainability, the work integrates controlled-release fertilizers, biochar, and LDH modification to enhance nutrient use efficiency and mitigate environmental runoff. Mg/Fe-LDH was directly synthesized on biochar via a co-precipitation approach, loaded the composite with phosphate by anion exchange, and characterized the material using elemental analysis, N2 Brunauer-Emmett-Teller (BET) determinations surface area analysis, and x-ray photoelectron spectroscopy to confirm successful LDH modification on Douglas fir biochar, and high surface area with accessible active sites. The synthesis yielded a stable P-Mg/Fe-LDH biochar with enhanced dispersibility and phosphate-buffering capacity, enabling controlled-release fertilization. In greenhouse experiments, bush beans grown with the P-Mg/Fe-LDH biochar exhibited improved growth metrics, including increased yield (beans fresh weight of 31.7 g), biomass (plant dry weight of 6.3 g), plant height (32.8 cm), and improved nutrient uptakes (1.88 mg (P) g-1) at 100.88 kg (P2O5) ha-1 compared with unfertilized controls and conventional P fertilizers, indicating efficient, controlled-release phosphate delivery and sustained nutrient availability. The results demonstrate that integrating LDH-modified biochar can enhance P uptake and plant growth while reducing leaching losses. Overall, this study highlights the strategic significance of combining biochar, layered double hydroxides, and controlled-release formulations to advance sustainable nutrient management and improve crop performance in agroecosystems. The findings offer a promising pathway for environmentally conscious fertilizer design and soil amendment strategies that align with global goals for resource efficiency and food security. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/727001v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@316444org.highwire.dtl.DTLVardef@adcd48org.highwire.dtl.DTLVardef@8068aforg.highwire.dtl.DTLVardef@58d623_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Niche-based selection and metabolic plasticity in the microbiome: Chronic press disturbances reconfigure the taxo-phenomic landscape of an industrialized riverine ecosystem

Devpura, N.; Jain, K. R.; Madamwar, D.

2026-05-22 microbiology 10.64898/2026.05.21.726876 medRxiv
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Riverine ecosystems particularly in industrialized environment are subjected to chronic press disturbances, resulting from the decadal release of synthetic organic compounds and other xenobiotics. While indigenous microbial communities are highly sensitive to such stressors, the resulting metabolic restructuring and functional reshaping of the microbiome, driven by these long-term anthropogenic pressures remains poorly characterized. In this study, a microbial ecology of Bhadar River flowing across the Jetpur Industrial Estate, (Jetpur) were studied. Using a cross-sectional comparative approach, soil/sediment samples were collected from the diverse polluted and non-polluted sites from the estate. The taxonomic profiling using 16S rRNA gene amplicon sequencing, taxo-phenomic shifts (through metaphenomics) was studied, while the functional potential of metabolic pathways was validated using high-resolution shot-gun metagenomic study. Due to prolong pollution, the samples were rich in sulphur (9809 to 12391 mg/L), where polluted samples were having elevated COD (2432 to 4150 mg/L) as well as BOD (1000 to 1420 mg/L) values, along with the presence of heavy metals (e.g., Fe, Mg). Results revealed a distinct taxonomic shift at both the bacterial and archaeal levels. In non-polluted sites Proteobacteria (33 to 57%) dominated along with Acidobacteria and Actinobacteria, with diverse genera like Alcaligenes and Serratia. Whereas, polluted sites exhibited marked increase in Bacteroidetes (13 to 29%), Firmicutes, and Synergistetes and genera like Alkalitalea, Mesotoga and Desulfomicrobium, reflecting anaerobic, fermentative, and sulfate-reducing phenotypes. The archaeal communities at polluted sites were dominated by Euryarchaeota (78 to 99%), specifically methanogenic genera of Methanosaeta and Methanocalculus, contrasting with the Methanomassiliicoccus dominance in non-polluted areas. The alpha-diversity was marginally higher in polluted sites (Shannon: 4.11 to 4.81 vs. 3.81 to 5.39 (non-polluted)), but beta-diversity underscored clear separation (94% variance explained by pollution). The shot-gun metagenomic analysis indicated a substantial enhancement in anaerobic metabolic capacities within the polluted microbiome, primarily in sulphur respiration (dissimilatory sulfate reduction), methanogenesis (elucidating biogenic pathways), along with nitrogen cycling (identifying key denitrification and ammonification genes). The polluted microbiome have developed the potential to metabolise/degrade complex aromatic compounds (pcaK for benzoate/protocatechuate transport) and heavy metal resistance. The strong positive co-occurrences among anaerobic phyla (Thermotogae, Synergistetes, Bacteroidetes) in polluted sites was established, indicating syntrophic interactions for xenobiotic metabolism. These findings provide a theoretical ecological model for perturbed industrial ecosystems, emphasizing the role of habitat selection in shaping microbial functional diversity and demonstrate the remarkable adaptation of autochthonous communities to persistent press disturbances.

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Phosphoproteomics in Daphnia magna as a tool to decipher molecular mechanisms in ecotoxicological studies

Wilde, M. V.; Stöckl, J. B.; Kösters, M.; Rupprecht, M. M.; Brehm, J.; Schwarzer, M.; Otte, K. A.; Laforsch, C.; Fröhlich, T.

2026-05-05 pharmacology and toxicology 10.64898/2026.05.01.721871 medRxiv
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Pollution of aquatic environments poses an increasingly severe threat to ecosystems worldwide, and understanding its molecular consequences for aquatic organisms requires extensive research and the development of advanced analytical tools. Phosphoproteomics can be particularly valuable for this purpose, as shifts in phosphorylation states can serve as early molecular indicators of toxic exposure. The cladoceran Daphnia is a keystone species in aquatic ecosystems, linking lower and higher trophic levels, and is therefore widely used as a model organism in ecotoxicology to study biological consequences of pollution. Here, we present a simple and effective strategy to analyse the phosphoproteome of Daphnia magna, a commonly used Daphnia species in ecotoxicology. Following TiO2-based phosphopeptide enrichment and LC-MS/MS analysis, we identified a comprehensive dataset of 3,532 phosphorylation sites across 1,329 phosphoproteins. These proteins were especially involved in signaling pathways and cellular structure and the vast majority have not yet been demonstrated in other Daphnia species. In conclusion, our results demonstrate that a straightforward phosphoproteomic LC-MS/MS workflow in D. magna can serve as a powerful tool for investigating adverse molecular effects caused by anthropogenic pollution, such as microplastics or pharmaceuticals. Statement of significanceThe dataset presented here demonstrates the feasibility of a simple yet effective strategy to perform phosphoprotemics in Daphnia magna, and it will be particularly valuable for future ecotoxicoproteomics research using this model organism.

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Sustainable Microbial Biotransformation Of Cr(Vi) To Cr(Iii) In Tannery Effluent And Its Valorization Into Cr(Iii) Nanoparticles Via Tridax Procumbens-Mediated Green Synthesis

Asokan, N.

2026-04-24 microbiology 10.64898/2026.04.23.720289 medRxiv
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Environmental pollution from leather industries have become a menace. The microbial remediation of industrial waste and its reuse for agriculture could be a beneficial outcome. In present study, the bioremediated Cr III in the effluents are further converted to value product - Chromium oxide NP. This ensures double edged benefit as effluent is bioremediated and Chromium oxide NP with several applications is derived. A noteworthy advancement of the research involved the green synthesis of chromium oxide nanoparticles using Tridax procumbens. The effluent bioremediated can be used for agricultural purposes. By effectively characterizing tannery effluent and isolating chromium-tolerant bacteria, the study not only demonstrate a practical bioremediation solution but also showcase the potential of green synthesis in producing chromium oxide nanoparticles. In conclusion, this research marks a significant advancement in environmental science, leveraging both biological and nanotechnological innovations to address pressing challenges in pollution control. The present study focuses on a novel process of obtaining chromium oxide nanoparticle from tannery effluent with several applications derived from bioremediated tannery effluent using a cost-effective and eco-friendly process. The nanoparticle has a stable particle size and exhibit antioxidant, anti-diabetic properties. This product offers a breakthrough solution for the leather industry and healthcare sector. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/720289v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@192e96borg.highwire.dtl.DTLVardef@1aae28org.highwire.dtl.DTLVardef@19fd282org.highwire.dtl.DTLVardef@1b562f9_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Temporal emergence of functional dark matter in microbial responses to PFAS revealed by materials-based cultivation

Velaz Martin, M.; Rabe, K. S.; Meisch, L.; Vollmers, J.; Kaster, A. K.; Niemeyer, C. M.

2026-05-27 microbiology 10.64898/2026.05.27.728134 medRxiv
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Microbial responses to xenobiotic compounds are difficult to resolve due to environmental complexity and limited functional annotation. Here, we establish a materials-based cultivation framework using macroporous elastomeric silicone foams (MESIF) to capture microbial adaptation across environmental contexts and timescales. Using glyphosate as a model compound and per- and polyfluoroalkyl substances (PFAS) as a poorly understood class, we show that responses differ depending on the availability of established metabolic pathways. Glyphosate exposure induced rapid, pathway-specific functional enrichment with minimal taxonomic change. In contrast, PFAS exposure did not yield consistent taxonomic or annotation-based signals but instead produced responses that emerged over time and were primarily detectable at protein and genome-resolved levels. LC-MS analyses revealed transformation dynamics, including formation of shorter-chain products. These responses were not explained by known degrader taxa but involved uncharacterized proteins and microbial populations, highlighting the extent of functional "dark matter" in microbial responses to persistent contaminants.

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Meta-analysis reveals a distinct and uniform gut microbial signature associated with endocrine-disrupting chemicals-induced diabetes

Durairaj, K.; Gajendhran, B.; Manivel, G.; Gnanam, H.; Swaminathan, K.; Gilles, M.; Velmurugan, G.

2026-05-13 microbiology 10.64898/2026.05.13.724769 medRxiv
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In recent years, the synergistic role of endocrine-disrupting chemicals (EDCs) and gut microbiota in the development of diabetes has been increasingly documented in rodent models. However, most studies have focused on one or two EDCs with varying doses and exposure durations, limiting the identification of a shared microbial signature associated with EDC-induced glucose dysregulation. This meta-analysis aimed to identify a common gut microbiome pattern across rodent studies involving diverse EDC exposures linked to glucose dyshomeostasis. A systematic search yielded 3,748 studies, of which ten met the inclusion criteria, comprising sequence data from 189 samples. These studies evaluated gut microbiota alterations in diabetes induced by various EDCs, including pesticides, food additives, and heavy metals, across different exposure conditions. Meta-analysis revealed a consistent reduction in microbial diversity and an increased Firmicutes/Bacteroidetes ratio following EDC exposure. At the phylum level, Firmicutes, Proteobacteria, Desulfobacterota, and Patescibacteria were significantly enriched. Although beneficial genera such as Lactobacillus, Bifidobacterium, and Akkermansia showed a decreasing trend, these changes were not statistically significant. In contrast, xenobiotic-associated genera including Desulfovibrio, Pseudomonas, Parasutterella, and Candidatus Saccharimonas were significantly increased. Notably, sulfate-reducing bacteria were the only inflammation-associated group consistently elevated. These microbial alterations were distinct from those observed in high-fat diet-induced diabetic models. This study identifies a distinct gut microbiome signature associated with EDC exposure in rodent models of glucose imbalance. These findings suggest unique microbiome-mediated pathways in EDC-induced diabetes and highlight potential microbial targets for early intervention in environmentally driven metabolic disorders.

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Glyphosate, a herbicide, and fosfomycin, an antibiotic in clinical use- evidence of common selectable genotypes

Fanning, S.; Wall, K. D.; Campbell, A.; Marmion, M.; Kilroy, A.; Doyle, C.; Marshall, H.

2026-05-26 microbiology 10.64898/2026.05.15.725383 medRxiv
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The emergence of antimicrobial resistance (AMR) is increasingly linked to metabolic adaptation, yet the evolutionary routes underlying cross-resistance between structurally related compounds remain poorly understood. Here, whole genome sequencing (WGS) was used to analyse Klebsiella pneumoniae mutants evolved under sub-lethal glyphosate (GLP) or fosfomycin (FOS) exposure to determine how these stresses shape resistance and physiology. Sub-lethal GLP exposure increased FOS resistance, demonstrating cross-resistance between the two phosphonates. FOS-evolved mutants achieved high-level resistance through the accumulation of multiple mutations affecting the antibiotic target MurA, transport systems, and global metabolic regulation, producing a layered FOS resistance phenotype. In contrast, GLP-evolved mutants acquired similar functional classes of mutations but exhibited lower baseline FOS resistance, suggesting trade-offs between resistance and metabolic fitness. Further, analysis of FOS-evolved and GLP-evolved mutants across known bacterial GLP resistance mechanisms demonstrated a strong overlap. Comparative genomic analysis revealed a small, recurrent set of genes under selection in both evolutionary trajectories, with identical genomic loci repeatedly targeted, consistent with convergent evolution. Many of these changes were linked to central metabolism, redox balance, and cell surface regulation. For some isolates, a hypermutator phenotype was necessary to offset the potentially lethal effects of primary-target mutations through compensatory genomic adaptation. In conclusion, GLP and FOS select for shared adaptive networks that couple metabolic rewiring with AMR, revealing cross-resistance as an emergent property of global physiological reprogramming and providing mechanistic insight into ecological models of co-selection in environmental systems. Importance statementGlyphosate is a herbicide in current use worldwide. Its impact on the susceptibility of bacteria to antibiotics, remains to be described. This manuscript details a critical phenotypic and genomic analysis of shared resistance mechanisms between glyphosate and the antibiotic fosfomycin. Using Klebsiella pneumoniae, a zoonotic pathogen, this manuscript demonstrates that evolutionary adaptation to either compound results in a substantial overlap in gene mutations. Crucially, this manuscript shows that exposure to sub-lethal concentrations of glyphosate can increase resistance to fosfomycin. These findings reveal a link between agricultural chemical use and the emergence of cross-resistance to fosfomycin. By highlighting how environmental factors drive antimicrobial resistance, this study underscores an urgent need for revision of food safety and regulatory frameworks to protect One Health. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=185 SRC="FIGDIR/small/725383v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@d44420org.highwire.dtl.DTLVardef@1c4a5d1org.highwire.dtl.DTLVardef@1624052org.highwire.dtl.DTLVardef@16d08d4_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Phytoformic Gold in Ash Samples of Plants from the North Goa Iron Ore Mining Belt: Detection, Characterisation, X-ray Diffraction, and Spectroscopic Evidence for Biogeochemical Gold Nanoparticle Formation

Kamat, N. M.

2026-05-18 plant biology 10.64898/2026.05.15.725495 medRxiv
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8.4%
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Gold is widely distributed in the biosphere, and higher plants growing on geochemically anomalous substrates can accumulate significant amounts of gold. This study reports, for the first time from Goa, the detection, spectroscopic characterisation, and X-ray diffraction analysis of phytoformic gold -- biologically sequestered crystalline gold -- in the above-ground dry litter ash of six tree species (Acacia auriculiformis, Alstonia scholaris, Anacardium occidentale, Artocarpus heterophyllus, Ficus benghalensis, Syzygium cumini) growing on mining dumps within the North Goa Banded Iron Formation (BIF) Belt of the Western Dharwad Craton. Microgravimetric analysis of aqua regia-extracted heavy ash fractions revealed gold concentrations of 275-1100 ppm, two to five orders of magnitude above the crustal background ([~]0.004 ppm). Fourier Transform Infrared (FTIR) spectroscopy of 0.22{square}m membrane-filtered crude extracts confirmed the tetrachloroaurate(III) complex [AuCl{square}]{square} as the dominant dissolved gold species, with the diagnostic 1400-1700{square}cm{square}1 absorption envelope present in all six species. UV-Visible spectrophotometry confirmed chloroauric acid formation with a universal {lambda}max at 372.5{square}nm across all species. Powder X-ray diffraction (XRD) of heavy ash fractions yielded the characteristic FCC metallic gold reflections Au(111), Au(200), and Au(220) in all five species analysed. Application of the Debye-Scherrer equation to the Au(111) reflection (2{theta} = 38.2{degrees}, Cu K) established crystallite sizes of 17.7-31.8{square}nm, confirming that phytoformic gold exists as nanoscale crystalline particles in all species. Ficus benghalensis produced the largest and most crystalline gold nanoparticles (31.8{square}nm) and uniquely exhibited strawberry-shaped isomorphic auriferous siliceous biominerals designated phytoauroliths. The described low-cost protocol -- ashing, aqua regia extraction, membrane filtration, and multi-technique spectroscopic and diffraction confirmation -- constitutes a validated method for rapid biogeochemical gold anomaly detection. Applications in gold phytoextraction and mining waste phytoremediation are discussed.

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Adequate coating and change in morphology increase the performances of silver nanoparticular biocides

Pawłowski, B.; Błazyca, H.; Huotari, J.; Collin, V.; Chartier-Garcia, E.; Salo, S.; Darrouzet, E.; Jeremiasz, O.; Rabilloud, T.

2026-05-13 pharmacology and toxicology 10.64898/2026.05.11.724204 medRxiv
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Silver has been used as a biocide for centuries, mostly in health-oriented applications. However, as a biocide, silver is toxic not only to its intended targets, mainly bacteria and fungi, but also to all living cells. Because of this toxicity, it is desirable to use forms of silver that maximize the required biocidal activity while minimizing the amount of silver that will be released in the environment at the end of life of the product. Silver nano objects are a good compromise for such requirements. The high surface to volume ratio allows for good reactivity and thus good biocidal activity, while the small amount of silver present in nano objects allows for a limited environmental release at the product end of life. In this work, we tested three types of silver nano objects. The first type, polyvinylpyrrolidone-coated silver nanoparticles (nAg-PVP) were used as a control nanoparticle, as this type of nanoparticle is now widespread. We also manufactured and tested maltodextrin-coated silver nanoparticles (nAg-MD) and micrometric (20 {micro}m in two dimensions and a few nanometers in the third one) silver flakes ({micro}AgSF). For these three silver nano objects, we investigated the biocidal activity by stringent tests using both Staphylococcus aureus and Escherichia coli as target bacteria. In addition, we investigated toxicity on mammalian macrophages or keratinocytes cell lines, as well as on an insect hemocyte cell line. Our results showed that the two innovative silver nano objects (nAg-MD and even more {micro}AgSF), showed both a better bactericidal activity and a lesser toxicity than the reference nAg-PVP nanoparticles. In addition, we also checked that beyond toxicity, the silver nano objects did not induce an inflammatory reaction, making them safer to use.

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Common nitrification inhibitors exhibit varied physiological mechanisms on an ammonia-oxidizing microorganism

Dalkidis, D.; Malits, A.; Kerou, M.; Sajedi, H.; Afjehi-Sadat, L.; Schleper, C.; Karpouzas, D. G.; PAPADOPOULOU, E. S.; Hodgskiss, L. H.

2026-05-10 microbiology 10.64898/2026.05.10.724060 medRxiv
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Microbial ammonia oxidation, the first and rate-limiting step of nitrification, plays a central role in soil nitrogen cycling. It is most relevant in agricultural soils as nitrifiers compete with crops for ammonia-based fertilizers. Therefore, synthetic nitrification inhibitors are widely used alongside fertilizers to reduce the activities of dominant drivers of this process, i.e. ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the physiological responses of ammonia oxidizers remain poorly resolved. Here the response of the AOA Nitrososphaera viennensis to the nitrification inhibitors 3,4-dimethylpyrazole phosphate (DMPP) and allylthiourea (ATU) were investigated using a combination of functional genomics, physiological assays, and relief experiments. The results overturn earlier assumptions that DMPP and ATU act by chelating free copper. Both compounds affected ammonia oxidation and triggered broader shifts in energy metabolism and stress-response pathways, which diverged markedly between the two inhibitors. We propose a competitive inhibition of the ammonia monooxygenase complex with DMPP as it can be alleviated by additional ammonia and elicits activation of urea acquisition, while ATU acted as a non-competitive inhibitor generally inducing quiescence. Both modes of inhibition were associated with clear transcriptomic and proteomic signals that will be advantageous for the identification of mechanisms of other nitrification inhibitors in the future. Key word: Ammonia-oxidizing archaea, nitrification, nitrification inhibitors, archaea, nitrogen cycle

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Raman Spectroscopy Enables Real-Time Identification and Monitoring of Plastic Biodegradation Metabolites

Pedari, S. N.; Hu, Y.; McMullin, D. R.; Heidarian, P.; Brady, A.; Gregoire, D. S.

2026-06-19 microbiology 10.64898/2026.06.18.733202 medRxiv
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Managing plastic pollution is challenging because current physical and chemical recycling methods are inefficient and environmentally intensive. Biological recycling approaches have been framed as sustainable alternatives but are challenging to optimize due to a lack of process analytical technologies that provide real time data on microbial plastic metabolism. In this study we used Piscinibacter sakaiensis 201-F6, a model bacterium with a well-studied polyethylene terephthalate (PET) metabolism, to validate non-destructive Raman spectroscopy methods to monitor plastic biodegradation by tracking metabolite production. Cells were grown on PET and known metabolites stemming from PET metabolism. Raman spectroscopy was used alongside destructive mass spectrometry techniques to monitor PET metabolite production and uptake under different growth conditions. Although cells grew effectively using PET, Raman spectroscopy did not detect the known PET metabolite terephthalic acid during growth assays. Instead, Raman detected isophthalic acid (IPA), a metabolite not previously associated with PET metabolism whose identity was confirmed with LC-HRMS. Raman spectroscopy was also used alongside thermoanalytical techniques to predict the biodegradability of PET at different crystallinities through the release of IPA. This study frames Raman spectroscopy as a promising tool to study metabolic pathways for plastic recycling and optimize their application in situ.