Journal of Hazardous Materials

Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants with documented toxic effects, yet their multi- and transgenerational impacts on neurodevelopment and underlying mechanisms remain poorly understood. Here, we present a comprehensive study delineating the effects of developmental exposure to environmentally relevant concentrations of PFOS and PFBS on behavior, transcriptome, and genome-wide DNA methylation patterns in the directly exposed generation (F0) and their unexposed offspring (F1 and F2) in zebrafish. Both PFOS and PFBS altered larval behavior, linked to transcriptomic and DNA methylation changes in neuro-related pathways, even in the unexposed offspring. Importantly, specific DNA methylation changes in F0 were associated with behavioral outcomes in F2 animals, suggesting that these alterations could underlie transgenerational effects. Pathways associated with differentially methylated genes were prominently enriched for response to light and circadian regulation. Our findings demonstrate that developmental exposure to PFAS causes transgenerational behavioral effects in zebrafish and suggest that epigenetic changes induced by direct exposure may serve as markers for predicting outcomes in subsequent, unexposed generations. TEASERPFAS induce circadian-related epigenetic changes in zebrafish associated with behavioral impacts in unexposed offspring.

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.

The facultative methylotroph model organism Methylorubrum extorquens AM1 is a known lanthanide user, which has shed light on the role of rare-earth metals in biochemistry. The characterization of a methanol dehydrogenase (MDH) protein which requires lanthanides as an enzymatic cofactor outlined the question of how these metals are acquired from the environment. It has been proposed that mesophilic organisms as M. extorquens AM1 can produce siderophore-like molecules, which chelate, transport and traffic rare-earth elements into the microbial cell. Therefore, we performed the bioinformatic and chemical investigation of M. extorquens AM1 by using genome mining, the CAS and arsenazo assay, molecular networking and chemical analytical techniques. Our results showed that indeed Methylorubrum extorquens AM1 harbored a gene cluster to produce metal chelators. The chemical analysis confirmed the production of the known hybrid hydroxamate-citrate siderophores schizokinen A and N-deoxyschizokinen A, which are very likely the side products of the transformation of schizokinen and N-deoxyschizokinen. The determination of the lanthanide chelation activity of the schizokinen siderophores series against three different lanthanides (La, Eu and Lu) showed no coordination activity, thus ruling out the involvement of schizokinen siderophores in rare-earth metal transport.

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

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.

Bisphenol A (BPA) and Bisphenol S (BPS) exposure disrupt ovarian function and granulosa cell (GC) steroidogenesis. Extracellular vesicles (EVs) and their miRNA cargo, as mediators of cellular response to environmental stimuli, might be involved in fertility and folliculogenesis. This study explored modulation of microRNA expression after 48h BPA or BPS exposure (10 {micro}M) in ovine primary GC and EVs from corresponding conditioned medium (CM EVs). Small RNA sequencing of control (0h) and 48h treated GC, CM EVs as well as follicular fluid EVs allowed identification of 533 ovine miRNAs, including 129 new sequences. BPA did not alter miRNA expression in GC, while BPS decreased cellular oar-24b miR. In contrast, BPA modified expression of 4 miRNAs in CM-EVs, including 3 new sequences, and two miRNAs were modified by BPS. Both compounds reduced expression of sequence homologous to miR-1306. Further studies are required to decipher their roles in bisphenol toxicity in GC.

Organic amendments provide crops with nutrients, but can also add pollutants. Yet the fate of micronutrients such as zinc (Zn) and pollutants such as cadmium (Cd) in soil-crop systems is difficult to predict because of the complexity of amendments added to soils. We performed pot and incubation experiments to determine whether the soil availability, uptake and transfer to grain of Zn and Cd in wheat (Triticum aestivum) are linked to the composition of amendments. Three amendments with highly diverse chemical properties, including varied organic matter (OM) degradability, were applied to a non-contaminated, arable soil. Stable isotopes of 70Zn and 106Cd were used to trace metals taken up from inputs versus soil in wheat biomass. We found the amendment most enriched in rapidly degradable OM (poultry manure) led to the highest wheat uptake of input-derived Zn i.e., 87{+/-}14 mg Zn (kg soil)-1. This was 2.5 times higher than input-derived Zn uptake from the most degraded amendment (compost). We did not observe an increase in soil available Zn with amendment application. Thus, biotic processes resulting from soil-plant-microbial interactions led to the increase in wheat uptake of input-derived Zn with amendment enrichment in rapidly degradable OM. Amendments led to minimal uptake of input-derived Cd in wheat and did not increase soil available Cd. Furthermore, we found no significant increase in grain Zn and Cd concentrations with amendments compared to the control. Our results highlight how amendment OM composition affects soil availability and wheat uptake of Zn and Cd with organic amendment application.

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

2,4,6-Trinitrotoluene (TNT) is a recalcitrant and pervasive environmental pollutant. Although different environmental microbes have demonstrated their ability to degrade or transform TNT, the underlying genetic basis and cellular machinery remain unclear. In this study, we investigated bacterial strategies in response to TNT exposure in Pantoea sp. MT58 and P. putida KT2440 using proteomics and random barcode transposon-site sequencing (RB-TnSeq). Pantoea sp. MT58 was found to utilize TNT as a sole nitrogen source, whereas P. putida KT2440 exhibited only stress tolerance without assimilation. Pantoea sp. MT58 encodes multiple putative nitroreductases that were upregulated, yet deletion of these genes did not affect growth on TNT, revealing pathway redundancy. Furthermore, fitness profiling provided no evidence for genes involved in the canonical Meisenheimer-complex pathway associated with nitrite release. Instead, the data are most consistent with a sequential nitro-group reduction route in which nitrogen is ultimately recovered as ammonium, with nitrogen routed through the GS-GOGAT pathway with purine and urea pools as the candidate buffering architecture for TNT mineralization. Conversely, P. putida KT2440 relied on Ttg/RND efflux pumps and toluene tolerance proteins for survival without nitrogen assimilation from TNT. This work distinguishes routes for productive nitrogen assimilation from those involved in nitroaromatic tolerance, expanding the mechanistic understanding of anthropogenic compound metabolism to inform future bioremediation efforts.

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

Microbial methanogenesis is a major contributor to global warming and methane fluxes represent a loss of energy and electrons from industrial ecosystems. The chemical space of methane control strategies is still under-explored. Most known methanogenesis inhibitors target methanogenic archaeal enzymes. However, interference with syntrophic electron exchange in methanogenic systems presents an additional target for methane control. Here we show that hypophosphite (H2PO2-), an inorganic formate analog, is a potent and selective inhibitor of syntrophic methanogenesis versus primary fermentation in rice field sediments and cattle rumens. Hypophosphite is also generally recognized as safe and relatively non-toxic to plants and animals. Genetic screens and physiological assays in the model methanogen Methanococcus maripaludis S2 implicate formate metabolism as the target of hypophosphite inhibition. Currently, there is no known biological pathway for anaerobic hypophosphite oxidation and hypophosphite is stable in anoxic sediments for weeks to months. Given its widespread natural occurrence, we propose that hypophosphite may modulate carbon cycling in natural environments. Taken together, our results suggest that hypophosphite could be used as a safe, inexpensive, strategy for methane control in syntrophic methanogenic ecosystems.

Air pollution has been increasingly linked to adverse neurodevelopmental and neurodegenerative outcomes. While experimental and preclinical studies suggest that exposure to particulate matter (PM), particularly during gestation, may disrupt cognitive development, the impact of short-term PM exposure on cognitive and behavioral functioning in healthy young populations remains insufficiently explored in Spain. Moreover, few studies have incorporated individualized dosimetry models to estimate exposure more accurately. This study included 186 healthy young adults (mean age = 20.4 years) recruited from three Spanish cities (Teruel, Almeria, and Talavera) characterized by different pollution levels. Ambient fine and coarse PM concentrations were recorded 8, 15, and 30 days prior to psychological assessment. Instead of relying solely on raw in situ environmental measurements, individualized PM deposition was estimated using the Multiple-Path Particle Dosimetry Model (MPPD), allowing a more biologically meaningful exposure approximation. Psychological outcomes were assessed using validated questionnaires: DASS-21 (depression, anxiety, stress), BIS-11 (impulsivity), UCLA Loneliness Scale, and SWLS (life satisfaction). Behavioral performance was evaluated using computerized versions of the Attentional Network Task (ANT) and the Stroop Task. Blood NRF2 concentrations were analyzed as a biomarker potentially related to oxidative stress mechanisms. In situ data indicated that Talavera presented the highest pollution levels, followed by Almeria and Teruel. Linear regression analyses showed that coarse PM exposure across 8-, 15-, and 30-day windows significantly predicted poorer Executive Control Index performance in the ANT. Additionally, 15-day coarse PM and 30-day fine PM exposure were associated with greater cognitive interference. Oxidative stress markers were significantly associated with PM exposure levels. These findings support emerging evidence that short-term PM exposure may negatively affect executive and attentional processes even in healthy young adults. Further longitudinal research incorporating individualized exposure modeling is warranted to clarify causal pathways and underlying biological mechanisms. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/713644v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@1a0ac13org.highwire.dtl.DTLVardef@1812accorg.highwire.dtl.DTLVardef@120bf07org.highwire.dtl.DTLVardef@dd9a7c_HPS_FORMAT_FIGEXP M_FIG C_FIG

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.

Antibiotic residues exceeding selective concentrations for antibiotic-resistant bacteria have been detected in various environments, including manure, wastewater, and effluents from wastewater treatment plants. When these residues come into contact with soils, for instance, due to wastewater irrigation or fertilization with manure, they interact with soil constituents. Soil colloids (1-1000 nm), such as montmorillonite, have been observed to adsorb pharmaceuticals, including antibiotics. We investigated the effect of colloids on the bioavailability of ciprofloxacin and found, that added to bacterial growth medium, montmorillonite reduces, but does not completely prevent, the growth-inhibitory effect of the antibiotic. The bacteria were able to grow at up to roughly double the concentration of ciprofloxacin in the presence of montmorillonite. We show that the incomplete deactivation of ciprofloxacin was most probably caused by medium components that decreased the adsorption of ciprofloxacin to montmorillonite. We conclude that a selective potential of this highly active antibiotic in contaminated soils, which also contain nutrients enabling bacterial growth, cannot be ruled out. Environmental implicationAntibiotics such as ciprofloxacin are frequently detected in water bodies and soils due to wastewater irrigation or manure application. These residues raise concerns about environmental toxicity and antibiotic resistance. This study demonstrates that montmorillonite, a common clay mineral in soils, significantly reduces the antimicrobial efficacy of environmental ciprofloxacin concentrations by sorption. The findings reveal a natural attenuation mechanism that may influence the environmental fate and bioavailability of antibiotics. Understanding such interactions is critical for predicting antibiotic behavior in terrestrial systems and for designing more accurate environmental risk assessments.

Neurodevelopmental disorders, including autism spectrum disorder (ASD), are influenced by both genetic abnormalities and environmental toxicants. Among environmental risk factors, endocrine-disrupting chemicals such as bisphenol A (BPA) and pharmaceutical drugs such as valproic acid (VPA) have been associated with an increased risk of autism. In this study, human induced pluripotent stem cell (iPSC)-derived forebrain organoids were used to model early neurodevelopmental disruptions induced by BPA and VPA exposure. On day 62 of differentiation, forebrain organoids were treated with physiologically relevant concentrations of BPA or VPA for 28 days. Following treatment, morphological, molecular, and electrophysiological changes were assessed across experimental conditions. Both compounds produced distinct alterations in organoid morphology, neurodevelopmental gene expression, and network electrical activity, with VPA inducing markedly stronger effects. Overall, these data suggest forebrain organoids as a robust, physiologically relevant in vitro model system for studying neurodevelopment. This platform enables systematic investigation of environmental and pharmacological risk factors implicated in the pathogenesis of neurodevelopmental disorders.

Copper is widely used as a fast-acting antimicrobial, yet the strategies that allow bacteria to survive copper stress remain incompletely understood. Here, we characterize the transcriptional responses of Escherichia coli MG1655 to excess ionic copper using RNA sequencing and a genome-wide GFP-based promoter library. We applied 2 mM copper, which slows growth, and 8 mM copper, a near-lethal concentration. RNA-seq revealed extensive transcriptome remodeling, with 487 genes upregulated at 2 mM and 364 at 8 mM. Both concentrations strongly induced canonical copper-responsive systems, oxidative stress defenses, histidine biosynthesis, and multiple iron acquisition pathways - including enterobactin biosynthesis and transport - despite external iron failing to reduce copper toxicity. At 2 mM copper, additional pathways were activated, including heat-shock and protein-folding functions as well as lipid A, methionine and arginine biosynthesis. Copper exposure also repressed large gene sets: 486 genes at 2 mM, enriched for biofilm formation and pH elevation, and 217 genes at 8 mM, enriched for anaerobic metabolism. In contrast to the robust RNA seq results, we investigated the Horizon Discovery E. coli genome-wide GFP based promoter library as an alternative screening tool. However, in our experiments it showed low signal to noise ratios, limiting its suitability for large scale gene expression screening.

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.

One of the effects of the intensified agricultural activities involves environmental pollution by pesticides, which are bound to get into the soil and ultimately into the water sources through leaching. The recurrent exposure of soil microbiota to these poisonous substances facilitates the process of adaptive resistance and catabolic functions. In the current research, bacterial cultures taken in Karuppur and Salem pesticide-contaminated agricultural soils were filtered on their capability to decompose organophosphate pesticides. Two strong isolates, which were referred to as Bacillus sp. and Micrococcus sp. had a great level of tolerance and degradation capacity. Significant biomolecular changes in these isolates were observed after long-term exposure (three months) to organophosphate pesticides. A protein estimation showed a strong rise in the overall total protein content indicating the activation of stress-related and degradative enzymes. Genomic DNA damage was identified by DNA ladder assay, which is a genotoxic stress caused by pesticides. Thus, plasmid profiling also revealed a rise of copy number and change of the size of plasmids, implying potential adaption through plasmids and greater degradation potential. This evidence indicates that long-term exposure to pesticides leads to microbial adaptation in terms of physiological and genetic changes to allow survival in adverse environments. The isolates identified have great potential to be used in bioremediation strategies that will be used in detoxifying the soils that have been contaminated with organophosphate.

Abscisic acid (ABA) is involved in Cd tolerance in Arabidopsis, but the underlying mechanisms are unclear. In this study, we revealed that the ABI5-WRKY45-LSU1 axis confers the tolerance of Arabidopsis to Cd stress. Under Cd stress, the biosynthesis of ABA is increased, and the expression of transcription factor ABI5 is upregulated. Accordingly, the abi5-8 mutants show increased Cd sensitivity. ABI5 directly binds the ABRE element in the WRKY45 promoter to activate its transcription. Overexpression of WRKY45 rescues the Cd-hypersensitive phenotype of the abi5-8 mutant, placing WRKY45 downstream of ABI5. Transcriptome analyses identified LSU1 as a potential WRKY45 target. qRT-PCR, DUAL-LUC and EMSA experiments verified that WRKY45 binds the W-box cis-element in the LSU1 promoter to activate its expression. Overexpression of LSU1 enhances Cd tolerance by promoting the biosynthesis of non-protein thiols (NPT), glutathione (GSH), and phytochelatins (PC). Moreover, overexpression of LSU1 suppresses Cd sensitivity in the wrky45 mutant, confirming LSU1 acts downstream of WRKY45. On the other hand, we found that ATP sulfurylase 1 (APS1) interacts with LSU1 based in vitro and in vivo evidences. LSU1 stabilizes APS1, slows its degradation, and enhances APS1 activity, thus leading to increased NPT, GSH, and PC accumulation and improved Cd detoxification. Notably, overexpressing LSU1 did not rescue the Cd sensitivity of the aps1-1 mutant, indicating that LSU1 acts upstream of and depends on APS1. In short, we demonstrated a novel ABI5-WRKY45-LSU1 axis that regulates Cd tolerance through sulfur assimilation and phytochelatin synthesis. HighlightsO_LICadmium stress triggers ABA biosynthesis and ABI5 expression; ABI5 directly binds to ABRE motifs in the WRKY45 promoter and activates its transcription. C_LIO_LIWRKY45 transcriptionally activates LSU1, and LSU1 interacts with APS1 to stabilize it and elevate ATP sulfurylase activity, acting in an APS1-dependent manner. C_LIO_LIThe ABI5-WRKY45-LSU1 module enhances Arabidopsis Cd tolerance by boosting sulfur assimilation and GSH/PC-mediated Cd detoxification, rather than reducing Cd uptake. C_LI

Paralytic Shellfish Toxins (PSTs) are produced by certain species of cyanobacteria and dinoflagellates. Part of the PST biosynthetic pathway has been elucidated in cyanobacteria, and the implication of some sxt genes has been confirmed by experimental studies. Contrary to cyanobacteria, knowledge about PST biosynthesis in dinoflagellates is more limited and generally restricted to comparative studies with the cyanobacterial pathway. To investigate the specificity of the PST pathway in dinoflagellates, 16 toxic and non-toxic A. minutum strains from a recombinant cross were compared, without prior assumption on genes or metabolites involved in PST synthesis, using an integrative approach combining untargeted metabolomic and transcriptomic data. Among the 60 most distinguishing transcripts between toxic and non-toxic strains, only 3 sxt genes were present, sxtA4, sxtG, and sxtI. In contrast, non-sxt homologs were detected as highly discriminant between these two phenotypes. More specifically, a phyH homolog may act as the analog of sxtS found in cyanobacteria. Moreover, we identified four putative synthetic PST intermediates. Among these, Int-C2, correlated with the toxic phenotype, whereas 3 others were detected in both toxic and non-toxic strains, suggesting that these strains may share some parts of the biosynthetic pathway. Finally, our results showed that PST biosynthesis in dinoflagellate results from the activity of sxt genes, acquired by horizontal gene transfer from cyanobacteria, as well as from other genes not acquired from cyanobacteria, such as phyH.