Environmental Science: Processes & Impacts最新文献

{"title":"Fluorine mass balance in commercial stone sealers from the US market and evaluation of PFAS-free alternatives.","authors":"Eleni K Savvidou, Shivani Cott, Khushi Desai, Jonathan P Benskin, Hannah L Ray, Anna Young, Joseph G Allen, Heather D Whitehead, Graham F Peaslee, Ian T Cousins","doi":"10.1039/d5em00965k","DOIUrl":"10.1039/d5em00965k","url":null,"abstract":"<p><p>Widespread use of per- and polyfluoroalkyl substances (PFAS) by the building industry places it among the major consumers of these chemicals. At the same time, ambiguous labelling and a lack of PFAS measurements in building materials hampers the possibility for consumers to select products which are PFAS-free. To address this, 35 representative sealers from the United States (US) market purchased in 2021 were analyzed using a fluorine mass balance approach, combining total and extractable organic fluorine (TF and EOF, respectively) measurements with targeted PFAS analysis of 19 polar compounds. TF analysis showed that 81% of the sealers contained fluorinated compounds at concentrations ranging from <LOD up to 27 150 µg F g^-1. A comparison to EOF revealed that the fluorine in most products was extractable and organic (EOF range <LOD up to 24 073 µg F g^-1), and most likely PFAS. Nevertheless, targeted PFAS analysis could only account for up to 31% of EOF, pointing to the presence of polymeric PFAS and potentially other low molecular PFAS. Among the detected PFAS, polyfluoroalkyl phosphate esters (PAPs) were the dominant sub-class. Six products appeared to not contain intentionally added PFAS, with organosilicone chemistry identified as the main functional component. Notably, organosilicone-based compounds are also under regulatory scrutiny, and differing views on their risks highlight the broader challenge of identifying truly safer alternatives.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2272-2287"},"PeriodicalIF":4.2,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13378410/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148467971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of the toxicity of complex antibiotic mixtures with hormetic effects by an interpretable machine learning model.","authors":"Yuanfan Zhao, Mingjiang Xie, Jing Zhang, Renyong Jia, Huiyan Shen, Jin Zhang","doi":"10.1039/d6em00188b","DOIUrl":"10.1039/d6em00188b","url":null,"abstract":"<p><p>Hormesis, a phenomenon frequently found in some low-dose chemical mixtures and their individual components in the environment, remains a formidable challenge in environmental risk assessment. To address this, a novel interpretable machine learning model, DynaHorm-ERT (Dynamic Hormesis Extremely Randomized Trees), was developed by using micro-dynamic features (extracted from molecular dynamics simulations) and hormetic effect features and applied to predict the combined toxicity of complex antibiotic mixtures (five β-lactam antibiotics, four aminoglycoside antibiotics and chloramphenicol) on a freshwater organism <i>Vibrio qinghaiensis</i> sp.-Q67. The results showed that most of the antibiotics and their mixtures exhibited hormesis with J-shaped concentration-response curves characterized by \"low-concentration stimulation and high-concentration inhibition\". Interestingly, some complex mixtures containing non-hormetic components also exhibited significant hormetic characteristics. The established model successfully and accurately predicted their joint toxicity. SHAP analysis indicated that the intensity of the hormetic effect and micro-dynamic constraints were the core mechanisms of driving toxicity, and the model demonstrated excellent predictive performance by capturing the potency of ligands within the receptor pocket and the degree of their dynamic constraints. Applicability domain analysis and external validation further confirmed the reliability of the model in assessing mixtures exhibiting hormesis. The obtained results highlight the importance of incorporating mechanistic features into the construction of reliable predictive models, which provides new insights and a new method for the ecotoxicological risk assessment of mixtures with hormetic effects.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2208-2218"},"PeriodicalIF":4.2,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148402963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle-scale distribution of antibiotic resistance genes in municipal wastewater across short-term and variable flow conditions.","authors":"Olivia N Birch, Qixue Cui, Bhanuprakash Kamma, Justin C Greaves","doi":"10.1039/d6em00111d","DOIUrl":"10.1039/d6em00111d","url":null,"abstract":"<p><p>Antibiotic resistance genes (ARGs) are increasingly recognized as persistent contaminants in aquatic environments, with wastewater treatment plants (WWTPs) serving as critical control points for their removal and downstream dissemination. This study investigated the fate, particle size distribution, and hydrodynamic sensitivity of four clinically relevant ARGs, blaTEM, mefA, tetW, and vanA, across primary influent, primary effluent, and final effluent of a municipal WWTP in Bloomington, Indiana. ARGs were quantified using digital PCR and partitioned across particle size classes (60 µm, 0.45 µm, and 0.025 µm) <i>via</i> cascade filtration. All targets exhibited significant reductions between primary influent and final effluent (<i>p</i> < 0.0001), with log₁₀ reductions ranging from 1.5 (blaTEM) to 2.3 (vanA). Despite treatment, ARGs persisted in final effluent at concentrations up to 4.0-6.2 log₁₀ gene copies L^-1. Particle association analyses revealed a shift from dominance in the >60 µm fraction in influent to increased association with the 0.45 µm fraction in effluent, particularly for blaTEM, which exhibited up to 76.5% association with this size class in final effluent. Controlled hydrodynamic experiments demonstrated that high-speed mixing (640 rpm) promoted transient redistribution toward smaller particles (<0.025 µm), consistent with particle disintegration and extracellular DNA release, whereas low-speed conditions (50 rpm) favored stable aggregation. These findings demonstrate that ARG-particle associations are dynamic, gene-specific, and sensitive to flow conditions, highlighting the need to consider physical partitioning and hydrodynamics when modeling ARG transport, exposure risk, and treatment efficacy.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2152-2160"},"PeriodicalIF":4.2,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148416940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence and toxicity mechanisms of hexafluoropropylene oxide dimer acid (HPFO-DA, GenX) in aquatic species.","authors":"Eliana Maira Agostini Valle, Amany Sultan, Austin Lu, Emma Ivantsova, Christopher J Martyniuk","doi":"10.1039/d5em00971e","DOIUrl":"10.1039/d5em00971e","url":null,"abstract":"<p><p>Hexafluoropropylene oxide dimer acid (HPFO-DA) is marketed under the trade name \"GenX\" and is used as a replacement for other per- and polyfluoroalkyl substance (PFAS) like perfluorooctanoic acid (PFOA). However, there are growing concerns about its regulation due to environmental and health impacts in organisms. Here, we review literature regarding the prevalence and toxicity of GenX in aquatic species and performed molecular docking and computational analysis to identify mechanisms of GenX-induced toxicity. Studies report measurable body burden levels of GenX in fish and other aquatic species, indicating that exposure and uptake do occur, which can lead to sub-lethal biological effects (<i>e.g.</i>, developmental toxicity, oxidative stress, metabolic disruption, immune modulation, endocrine activity, neurobehavioral alterations). Effects on hormone receptor - mediated signaling (<i>i.e.</i>, estrogenic and thyroid pathways) were noted based on computational analysis. <i>In silico</i> molecular docking of GenX to several fish receptors (<i>e.g.</i>, estrogen, androgen, and thyroid hormone receptors) supported the potential for GenX to interact with key nuclear receptors, suggesting plausible mechanisms of endocrine disruption in fish. Molecular and omics-based analyses also revealed that GenX interferes with several pathways related to lipid and energy metabolism, as well as redox balance. Notably, several transcripts altered in abundance by GenX are related to the AGE-RAGE signaling pathway (Advanced Glycation End products (AGEs) bind to the Receptor for Advanced Glycation End products (RAGE)), which is related to oxidative stress and inflammation, and glucagon receptor (GCGR) signaling that activates transcription factors like CREB/CRTC2 and FOXO1 to promote gluconeogenesis. This review underscores useful toxicological endpoints for GenX in aquatic animals to guide future risk assessments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2133-2151"},"PeriodicalIF":4.2,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148416946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling nitrogen deposition with an ultra-fine mesh: application in farmland with dense river network.","authors":"Zaili Ling, Jiayi Xin, Tao Huang, Chaopu Ti, Lingyun Peng, Jianmin Ma","doi":"10.1039/d6em00304d","DOIUrl":"10.1039/d6em00304d","url":null,"abstract":"<p><p>Ammonia (NH₃) emissions from agriculture significantly impact aquatic ecosystems through the deposition of ammonia nitrogen (NH_<i>x</i>-N). Models established on a gridded map provide a useful tool to investigate NH₃ dispersion and deposition. However, coarse model grid cells in major atmospheric chemistry models often lead to large bias in modeled N burden due to NH_<i>x</i>-N deposition in small household farms, which are typical in Southeastern China with dense farmland water networks. Here, we first simulated atmospheric concentrations of NH₃ and NH₄⁺ in 2020 in Changshu, a representative area with developed agriculture and dense river and farmland water networks attached to the Taihu Lake Basin in Southeast China, using the WRF-CMAQ model. To address the bias caused by coarse model grids, we employed a large leaf model to calculate dry deposition velocities for NH₃ and NH₄⁺ at a high resolution of 10 meters. This allowed for a more accurate estimation of the nitrogen load to surface waters from re-emitted farmland NH₃. The results show that coarse particulate NH₄⁺ (CNH₄⁺) exhibited the largest dry deposition velocity, followed by gaseous NH₃ and fine particulate NH₄⁺ (FNH₄⁺). The dry deposition velocities of NH₃ and NH₄⁺ were significantly influenced by land use type. Our results indicate that approximately 118.0 tons of nitrogen from ammonia reemission from farmlands entered surface water in 2020 in Changshu <i>via</i> atmospheric NH_<i>x</i>-N deposition. The wet deposition of NH₄⁺ was the largest contributor (49.8%), followed by dry deposition of gaseous NH₃ (20.9%), CNH₄⁺ (20.7%), and FNH₄⁺ (8.6%), respectively.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2307-2319"},"PeriodicalIF":4.2,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment-associated Irgasan drives functional and taxonomic restructuring of marine nematode communities.","authors":"Ahmed Nasri, Amel Hannachi, Abdelwaheb Aydi, Aymen Wahbi, Fabio D'Agostino, Giuseppe Avellone, Ezzeddine Mahmoudi, Hamouda Beyrem","doi":"10.1039/d6em00108d","DOIUrl":"10.1039/d6em00108d","url":null,"abstract":"<p><p>Sediment-associated contaminants can profoundly alter benthic ecosystem functioning, yet their effects on meiofaunal processes remain poorly resolved. Here, we investigated the impacts of Irgasan (triclosan) enrichment in marine sediments on meiofauna, with a particular focus on functional and taxonomic responses of free-living nematodes from the Bizerte Lagoon (Tunisia). A one-month laboratory microcosm bioassay revealed marked differences between Irgasan-contaminated and uncontaminated sediments. High contamination levels led to significant declines in total meiofauna abundance, including nematodes, copepods, oligochaetes and amphipods, while polychaetes were comparatively unaffected. In parallel, nematode total biomass, taxonomic composition and functional trait structure were strongly altered across all Irgasan-enriched treatments. Multivariate analyses (nMDS and correspondence analysis) demonstrated a clear functional restructuring of nematode communities driven by changes in key biological traits, particularly the feeding strategy, adult body size and amphid morphology. Highly contaminated sediments were dominated by opportunistic and predatory species, whereas uncontaminated sediments supported microvorous and deposit-feeding taxa. These results highlight how sediment-bound Irgasan disrupts the benthic community structure by modifying functional trait distributions, with implications for ecosystem processes mediated by meiofauna in coastal sediments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"1987-1997"},"PeriodicalIF":4.2,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148255861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil organic matter composition controls neonicotinoid transport and accumulation to benthic macroinvertebrate communities in agricultural drains.","authors":"Noha F El Azab, Jade Gorman, Kaitlyn J Fleming, Jackson Ohrling, Vaughn Mangal","doi":"10.1039/d6em00394j","DOIUrl":"10.1039/d6em00394j","url":null,"abstract":"<p><p>Neonicotinoids are widely used in agriculture to manage insect pests; however, their application can harm the well-being of aquatic animals and non-target insects in surrounding ecosystems. While previous studies have identified relationships between neonicotinoid transport and soil chemistry in agricultural ecosystems, there is a lack of research exploring how the molecular properties of organic carbon in soils affect neonicotinoid mobility. In addition, there is even less research exploring the interconnected dynamics between neonicotinoid transport and nontarget biological endpoints, such as benthic macroinvertebrates. In this study, soil, stream sediment, and benthic macroinvertebrates were collected monthly across agricultural and naturalized land cover in Southern Ontario from April to October 2023 to quantify neonicotinoid levels in agricultural watersheds. Fourier transform ion cyclotron resonance mass spectrometry was used to characterize the molecular composition of water extractable organic matter in soil and sediment samples, and three neonicotinoids were detected using a triple quadrupole mass spectrometer. Thiamethoxam concentrations peaked early in the sampling period, reaching 6.27 ± 0.31 ng g^-1 in April before steadily declining, coinciding with reductions in scrapers-grazer functional feeding groups. Conversely, thiamethoxam levels in stream sediments exhibited a delayed peak, rising to 6.82 ± 0.94 ng g^-1 in later summer months, suggesting mobilization from soils in as little as three months after application. Overall, thiamethoxam emerged as the most frequently detected neonicotinoids in both soil and sediment samples and a significant positive correlation was observed between WEOM and thiamethoxam (Spearman <i>ρ</i> = 0.803, <i>p</i> = 0.022). Accumulated thiamethoxam is also likely transported by phoshrpus and sulphur-containing WEOM from soils to sediments, where thiamethoxam correlated with significant decreases in scraper-grazers population in stream sediments. Together, our results identify molecular signatures within the WEOM that can serve as indicators of enhanced thiamethoxam transport from soils to sediments and highlight the rapid effects of neonicotinoids on benthic macroinvertebrate communities.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"2046-2062"},"PeriodicalIF":4.2,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148366290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freeze-thaw impacts on physicochemical properties and mineral-organic components of various loess soils.","authors":"Zhongwei Yang, Yifan Yao, Yufeng Jiang, Jingru Diao, Longmiao Yuan, Yingqin Wu","doi":"10.1039/d6em00241b","DOIUrl":"10.1039/d6em00241b","url":null,"abstract":"<p><p>Freeze-thaw cycles (FTCs) are a critical factor in the environmental changes of soils in cold regions, significantly impacting their structure and composition through physical stress and chemical migration resulting from water freezing and thawing. Currently, there is a lack of systematic research on the differences in the physicochemical properties and micro-mechanisms of various loess types during FTCs, which limits the theoretical basis for soil management and pollution prevention in cold regions. To address this knowledge gap, this study selected five typical loess types from Northwest China, including sierozem, gray-brown soil, loessial soil, black loess soil, and meadow soil. A novel freeze-thaw simulation was conducted over 10 cycles ranging from -10 °C to 10 °C, allowing for a systematic analysis of the effects of FTCs on soil pH, water content, bulk density, porosity, organic carbon content, cation exchange capacity, inorganic oxides, and heavy metal content. Advanced spectroscopic techniques, including Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), were employed to elucidate the micro-response mechanisms of soil minerals and organic components. The results indicated that FTCs caused a decrease in soil bulk density by 8.3-15.7% and an increase in porosity by 12.4-19.8%, with the most significant structural changes observed in meadow and loessial soils. Organic carbon content declined by 7.1-22.4% across the five soils, with the largest loss of 22.4% in black loess soil. XRD analysis revealed that the full width at half maximum of the 001 crystal plane diffraction peak of illite increased by 17-29%, indicating alterations in the interlayer structure of the mineral. The intensity ratio of the peaks at 1620 and 1030 cm^-1 in the FTIR spectrum decreased by 15-35%, suggesting that FTCs may disrupt the binding interactions of mineral-organic complexes. Concurrently, the leaching fractions of Cd and Pb increased by 10-25% in most soils, coupling heavy metal activation with organic carbon release. This study provides the first systematic elucidation of the synergistic evolution of physicochemical properties and microstructure in different loess types under FTCs, offering a critical scientific basis for soil quality assessment and engineering protection in cold regions.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"1941-1952"},"PeriodicalIF":4.2,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148337074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrophobic model systems for oil film photooxidation: part II: direct and indirect pathways controlled by oxygen and molecular structure.","authors":"Bin Wu, Manoj Rayaroth, Christoph Aeppli","doi":"10.1039/d6em00173d","DOIUrl":"10.1039/d6em00173d","url":null,"abstract":"<p><p>Sunlight-driven oil photooxidation alters petroleum composition and influences the environmental fate of spilled oil; however, the mechanisms controlling hydrocarbon photolysis remain poorly understood. To address this, we investigated the direct and indirect photodegradation of saturated and aromatic hydrocarbons in a hydrophobic model petroleum system. Photosensitizers (phenalenone, tetracene, xanthone, naphthol, and anthraquinone) and quenchers (furfuryl alcohol, sorbic acid, and DABCO) were used to probe reactive pathways in these hydrophobic solvent systems. The effects of solvent type and oxygen saturation were also examined. Results indicated that PAHs with fewer than three rings exhibited limited direct photoreactivity due to limited overlap with solar radiation, whereas three-ring or larger-PAHs were photoreactive. Alkylation substantially increased direct photolysis rates for anthracene, pyrene, and benzo[<i>a</i>]pyrene. For anthracene and 9-methylanthracene, oxygen availability did not affect direct photodegradation, suggesting oxygen plays a minor role under the tested conditions. Except for 9-methylanthracene, photosensitizers markedly enhanced transformation of most three-ring or larger PAHs, and this effect was suppressed by singlet oxygen quenchers, confirming the role of reactive oxygen species. Saturated and monoaromatic hydrocarbons showed no indirect photoreactivity. For indirect photolysis, reduced oxygen saturation decreased degradation for anthracene, methylpyrene, and methylbenzo[<i>a</i>]pyrene, while other compounds were unaffected. Methyl substitution produced position-specific effects across PAHs, leading to variable photoreactivity. The findings of this study highlight the complex photochemical behavior of PAHs in oil films, where multiple direct and indirect pathways operate simultaneously in a highly substrate- and oxygen-dependent manner. These results further emphasize the importance of reactive oxygen species, energy transfer, and quenching dynamics in controlling oil photooxidation.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"1974-1986"},"PeriodicalIF":4.2,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148255665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biofilm mediated mineral alteration of limestone by <i>Bacillus cereus</i> and sulphate reducing bacterial consortia: impacts on quality grading, stability, and composition.","authors":"Yimtar L Pongen, Balachandar Chinnappa, Saivenkatesh Kiran Bollapragreate, Parthipan Punniyakotti, Thirumurugan Durairaj","doi":"10.1039/d5em00841g","DOIUrl":"10.1039/d5em00841g","url":null,"abstract":"<p><p>Microbial mediation of mineral transformation plays a vital role in both geochemical processes and industrial applications. This study investigates native bacterial communities from Upper Cretaceous limestone fossil deposits in Ariyalur, Tamil Nadu, India, focusing on their role in altering the composition of the limestone. A total of eleven morphologically distinct bacterial isolates and a sulphate-reducing bacterial (SRB) consortium were isolated and screened for urease production and sulphate-reducing ability under site-specific conditions. Biofilm formation, evaluated using confocal laser scanning microscopy (CLSM), revealed isolate-specific differences in biofilm architecture. The urease-positive isolate (CS4), <i>Bacillus cereus</i>, produced a thick matrix-rich biofilm (81.34 ± 0.84 µm) associated with mineral precipitation. In contrast, the SRB consortia formed a thinner biofilm (42.18 ± 0.87 µm), which promoted mineral dissolution. SEM/EDX and XRD analysis confirmed significant changes in the limestone texture and mineral composition of CS4-treated samples, including increased calcium content (∼6.39%) and reduced phosphorus (∼11.68%), sulphur (∼2.33%), and chlorine (∼3.07%), which are elements detrimental to cement quality. The study also indicates that sulphate reduction may be an important factor in the genesis of microbial-mediated limestone fossil formation. These findings suggest that microbial biofilm dynamics and urease-mediated processes can selectively enhance limestone quality, providing new insights into selective mineral leaching, biocalcification, and microbial-mineral interactions with potential industrial relevance.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":"1953-1964"},"PeriodicalIF":4.2,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148256177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}