Water Research最新文献

{"title":"Dehalobacter-Mediated Reductive Dechlorination of the Organophosphorus Insecticide Chlorpyrifos in Mangrove Sediments","authors":"Jiaying Li, Yin Zhong, Sen Yang, Junhong Wu, Yanting Zhang, Yanhong Zeng, Jianzhong Song, Xifen Zhu, Dan Li, Juan Ling, Zhiqiang Yu, Max M. Häggblom, Ping’an Peng","doi":"10.1016/j.watres.2026.127280","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127280","url":null,"abstract":"Mangrove sediments are important sinks for organic contaminants, including the widely used chlorinated organophosphorus insecticide chlorpyrifos (CPF). Although CPF degradation under oxic conditions has been extensively studied, its anaerobic transformation in reducing coastal environments remains poorly understood. Here, a mangrove sediment-derived anaerobic enrichment culture achieved nearly complete transformation of 10 mg L<ce:sup loc=\"post\">−1</ce:sup> CPF within 10 days. Ultraperformance liquid chromatography–Orbitrap high-resolution mass spectrometry (UPLC-Orbitrap-HRMS) revealed the formation of a mono-dechlorinated CPF product, which was tentatively assigned as <ce:italic>O,O</ce:italic>-diethyl <ce:italic>O</ce:italic>-(3,5-dichloro-2-pyridinyl) phosphorothioate based on tandem mass spectrometry (MS/MS) evidence and density functional theory (DFT) calculations of C–Cl bond dissociation energies. The enrichment culture also reductively dechlorinated 3,5,6-trichloro-2-pyridinol (TCP), a common CPF transformation product, primarily to 5,6-dichloro-2-pyridinol, with Ecological Structure-Activity Relationships (ECOSAR) modeling predicting lower aquatic toxicity for the dechlorinated products than for their parent compounds. 16S rRNA gene amplicon sequencing and metagenomic analyses revealed marked enrichment of <ce:italic>Dehalobacter</ce:italic> during active CPF transformation, strongly implicating this organohalide-respiring lineage in CPF dechlorination. A high-quality <ce:italic>Dehalobacter</ce:italic> metagenome-assembled genome harboring 39 <ce:italic>rdhA</ce:italic> homologs was recovered. Integrated metatranscriptomic and metaproteomic analyses further prioritized four candidate reductive dehalogenases (CPF-RDH1/2/3/9), with CPF-RDH2 showing the strongest proteomic support. Together, these findings uncover an overlooked anaerobic transformation route of CPF through direct reductive dechlorination and highlight the potential role of <ce:italic>Dehalobacter</ce:italic>-associated organohalide respiration in the environmental fate of chlorinated organophosphorus contaminants in mangrove sediments.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"18 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"FOG Deposit Accumulation in a Pipe-Loop System: Influences of Wet Wipes, Facial Tissues and Food Debris on Rheology and Flow Behaviour","authors":"Hamza Hassan Yusuf, Felicity Roddick, Veeriah Jegatheesan, Biplob Kumar Pramanik","doi":"10.1016/j.watres.2026.127264","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127264","url":null,"abstract":"Fat, oil and grease (FOG) accumulation is a major cause of sewer blockages worldwide, yet the mechanisms governing deposit formation and their hydraulic impacts remain poorly understood under realistic flow conditions. This study introduces a laboratory-scale semi-continuous pipe-loop system that replicates sewer hydraulic conditions to investigate the formation, spatial distribution and flow behaviour of FOG deposits. The system enables controlled observation of deposit growth and its interactions with common sewer solids, including food debris (WFFD), facial tissues (WFFT), wet wipes (WFWW) and combined wastes (WWA). The mass of accumulated deposits increased by 48.7%, 66.4%, 64.7% and 67.5% in the presence of WFFD, WFFT, WFWW and WWA, respectively, compared with FOG-only deposits which had an accumulated mass of 47.88 ± 1.81 g. The spatial distribution of accumulated deposits containing solids was non-uniform, with greater deposit thickness observed near the inlet and a gradual decrease towards the outlet of the pipe loop. The average thickness of deposits with WFFT, WFWW and the WWA were 15.2 ± 4.24 mm, 14 ± 0.57 mm and 15.75 ± 0.52 mm, respectively, and the maximum thickness reached about 23 ± 5.42 mm, 20.5 ± 4.95 mm and 26.5 ± 4.95 mm, respectively. The rheological behaviour of these deposits was characterised using Herschel-Bulkley and Power Law models and integrated with computational fluid dynamics (CFD) simulations to quantify their hydraulic implications. Rheological analysis revealed that post-yield stress (<mml:math altimg=\"si6.svg\"><mml:mrow><mml:mi>τ</mml:mi><mml:mo linebreak=\"goodbreak\">&gt;</mml:mo><mml:msub><mml:mi>τ</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:mrow></mml:math>) plays a critical role in the development of sewer blockage, governing deposit mobility after yielding. Deposits containing solids show substantial yield stress and consistency index, indicating strong resistance to flow even after the yield threshold is exceeded. CFD simulations further demonstrated that deposit density strongly influenced pressure gradients, with higher densities generating increased inlet pressures as flow velocity increases, while yield stress directly governed wall shear stress development. Overall, the integrated pipe-loop-rheology-CFD framework provides a mechanistic understanding of FOG deposit behaviour and offers a robust platform for evaluating blockage risks and designing more resilient sewer systems.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"7 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"A hybrid nature-based ecological restoration system stabilizes water quality and food-web recovery in a continuous nutrient-loaded pond","authors":"Jiannan Li, Guohong Liu, Yan Tian, Yanbo Liu, Ye Qiu, Yujie Feng","doi":"10.1016/j.watres.2026.127276","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127276","url":null,"abstract":"Small water bodies are important hotspots for nutrient transformation but are highly vulnerable to persistent anthropogenic loading. Ecological restoration is often evaluated by short-term pollutant removal, whereas the processes that sustain water quality and ecological function under continuing external inputs remain less understood. Here, we implemented a hybrid nature-based ecological restoration system integrating ecological floating beds, microbial electrochemical system-enhanced floating beds (ECOFB-MES), submerged macrophytes, and ecological revetments in a 2,600-m<ce:sup loc=\"post\">2</ce:sup> shallow rural pond continuously receiving secondary treatment effluent and rainfall-driven runoff. Across pronounced seasonal variability (5-36°C), the water quality consistently met the surface water Class III standard (GB 3838-2002) and effectively prevented eutrophication. Water-quality persistence was accompanied by aquatic-community recovery, characterized by declining phytoplankton abundance and increasing zooplankton and benthic macroinvertebrates. Increasing sediment ORP coincided with increased Fe(III) abundance and phosphorus fraction redistribution, indicating a shift toward stronger phosphorus retention and a lower potential for internal phosphorus release. Microbial-community restructuring, electrochemically mediated electron transfer, plant nutrient assimilation, and sediment stabilization provided complementary pathways for nutrient transformation and retention. Greenhouse-gas measurements further indicated potential carbon-related co-benefits. These results demonstrate that sustained improvement in nutrient-loaded small water bodies can emerge from coordinated regulation of the water column, sediment-water interface, and aquatic biological community. This study provides field-scale evidence for advancing small-water-body restoration toward integrated ecological stabilization under persistent anthropogenic pressure.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"1 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Decoding water pollution sources of the Yellow River Basin using semi-volatile organic pollutants: From potential threats to chemical fingerprints","authors":"Quanzhen Liu, Yongchang Xie, Rong Li, Qingwei Bu, Xiong Xu, Chuan Du, Lihua Lin, Zhengxin Gan, Donghong Wang","doi":"10.1016/j.watres.2026.127273","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127273","url":null,"abstract":"The Yellow River Basin (YRB) supports a population of 160 million but only has 2% of China’s water resources. The high-density distribution of coal chemical enterprises (CCEs) further exacerbates water pollution and scarcity. However, supporting evidence on CCE-associated pollution remains lacking due to limited monitoring data and insufficiently discriminative methods. Here, we established a pollution source tracing system based on nontargeted analysis (NTA) and targeted analysis (TA) monitoring data of semi-volatile organic pollutants (SVOPs) that widely exist in CCEs, to reveal the potential industrial sources of ambient waters in the YRB within a reference library. An inventory of 528 SVOPs was compiled via NTA of 59 source-terminal water samples. Furthermore, we developed an entropy similarity metric to quantitatively estimate the chemical fingerprint resemblance from diverse industrial effluents. Within a reference library of nine industrial effluent profiles, the entropy similarity of CCEs in the study area was at least twice that of other industries, with the Fenhe River most severely affected, potentially accounting for the elevated levels of conventional monitoring parameters. TA characterized the source-to-receptor discharge patterns of 134 SVOPs, and discriminated 88 CCE-associated SVOPs. A high proportion of heterocyclic compounds (e.g., 1,3-diazaspiro[4.5]decane-2,4-dione, isoquinoline and indole) serves as CCE-associated indicators. Besides, 12 newly found CCE-associated SVOPs such as 1,3-diazaspiro[4.5]decane-2,4-dione posed medium and high ecological risks. Effective discharge control of CCE-associated SVOPs can lower ecological risks by 3.6%-48.5% under a similarity-based hypothetical scenario. These findings will facilitate the pollution source tracing of water samples and support the sustainable development of the basin.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"64 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Mechanistic Insights into Static Magnetic Field-Enhanced Removal of Polycyclic Aromatic Hydrocarbons from Wastewater by Constructed Wetlands: Computational Simulation and Microbial Community Dynamics","authors":"Jiahao Dong, Peiqiong Liu, Yan Kang, Jiaxing Lu, Linlan Zhuang, Huijun Xie, Haiming Wu, Zhen Hu, Zizhang Guo, Jian Zhang","doi":"10.1016/j.watres.2026.127275","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127275","url":null,"abstract":"Microbial degradation is the dominant pathway for pollutant removal in constructed wetlands (CWs). Here, static magnetic fields (SMFs) were employed as a promising strategy to enhance pollutant removal, as they can effectively promote microbial activity and metabolic capacity without additional chemical amendments. Here, COMSOL-based magnetic-field simulation, plant physiological assays, extracellular polymeric substance (EPS) characterization, and metagenomics were integrated to examine the regulatory effects of SMF intensity and spatial heterogeneity on microbial community structure, functional potential, and benzo[k]fluoranthene (B[k]F) biodegradation. B[k]F removal showed an intensity-dependent threshold response, with 150 mT increasing mean removal efficiency by 14.31% relative to the control. COMSOL simulations showed that 150 mT produced the largest effective SMF zone, covering 39.53% of the reactor volume. This treatment enhanced plant photosynthetic performance, potentially supporting rhizosphere microbial metabolism through plant-derived carbon and oxygen supply and increased EPS concentrations to 30.01 ± 3.19 and 23.59 ± 4.68 mg L⁻¹ in the upper and lower layers, respectively. Metagenomic analysis revealed enrichment of key polycyclic aromatic hydrocarbon (PAH) degrading bacteria affiliated with <ce:italic>Actinomycetota</ce:italic> (45.20%). At 150 mT, enhanced tricarboxylic acid cycling and oxidative phosphorylation accelerated microbial energy metabolism and promoted conversion of high-molecular-weight B[k]F into low-molecular-weight aromatic acids. These findings suggest that optimized SMFs enhance PAH removal through coordinated plant–microbe responses, thereby providing a basis for designing magnetically intensified CWs as a chemical-free wastewater treatment strategy.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"20 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"The overlooked hydroxylation of NOM contributes to the additional generation of ·OH in H2O2/Fe(III)/NOM system","authors":"Hai-Teng Gu, Zhuo-Yu Li, Bai-yu Yang, Chen He, Chun-Mao Chen, Zongyao Zhou, Jun Ma","doi":"10.1016/j.watres.2026.127272","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127272","url":null,"abstract":"Natural organic matter (NOM) was reported to accelerate the Fe(III)/Fe(II) cycle in Fenton-like system. Herein, the promotional effect of NOM on ·OH generation through initiation reactions and propagation reactions was quantified with competition method and scavenger assay. The generation of ·OH in competition method was 18.4 times higher than that in scavenger assay, indicating the dominant contribution of propagation reactions to the generation of ·OH in the presence of Suwannee River fulvic acid (SRFA). The total phenolic content increased from 3.4 μM to 4.4 μM in competition method while it decreased from 3.1 μM to 2.9 μM in scavenger assay. This change was caused by the oxygen addition reaction in the oxidation process of NOM by ·OH, leading to the generation of polyphenols such as tannin. NOM with newly formed phenolic groups had higher Fe(III) reducing capacity, increasing Fe(II) concentration from 2.6 μM before reaction to 3.0 μM after reaction in competition method and promoting ·OH generation through propagation reactions. The result of kinetic modelling indicated that non-redox-active groups in SRFA reacting with ·OH in competition method produced new reductive groups, which promoted Fe(III) reduction and ·OH generation. This study advances the understanding of how NOM and its transformation products regulate ROS generation through propagation reactions in Fenton-like systems.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"44 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Spectral–temporal autofluorescence analysis for rapid and label-free microplastic differentiation in aquatic environments","authors":"Jonas Rottmann, Sebastian Sawer, Manuel Ligges, Nicolas Schierbaum, Karsten Seidl","doi":"10.1016/j.watres.2026.127236","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127236","url":null,"abstract":"Although plastic products facilitate our life essentially, the resulting pollution increasingly harms the terrestrial and aquatic environment and our health. To mitigate this pollution and to establish effective recycling strategies, analytical methods to specifically detect different plastics are required. However, common analytical methods such as Raman, near-infrared (NIR), and Fourier transform infrared (FTIR) spectroscopy are constrained by their complex instrumentation, their signal absorption in water and/or their low signal intensities, resulting in long measurement times. In this work, we demonstrate an analytical method to overcome these limitations and detect different plastic materials based on their intrinsic autofluorescence. We investigated 22 different plastic materials and identified characteristic fingerprints in their spectral and temporal autofluorescence using a phasor-based analysis. With the spectral and temporal autofluorescence, we could identify different plastic materials with an accuracy of up to 87.9% and 83.1%, respectively. The accuracy can even be improved to 95.7%, when combining the analysis of individually measured spectral and temporal autofluorescence signals. These results showcase that using spectral and temporal autofluorescence signals is a viable approach for plastic detection and differentiation, particularly when combining spectral and temporal dimensions. The, here, demonstrated analytical method comprises the advantage of high signal intensities, working in the spectral water window and needing no labels. Consequently, it can be implemented into high-throughput methods for microplastic detection in liquid sample analysis such as flow cytometric, as demonstrated in this work. This has huge potential for environmental in-field monitoring which would support the effective mitigation of plastic pollution.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"18 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Increasing precursor concentrations does not always enhance dichloroacetonitrile formation or yield during UV/monochloramine treatment","authors":"Xiao Li, Xiaochong Xun, Xiaoyu Tan, Baiyang Chen","doi":"10.1016/j.watres.2026.127261","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127261","url":null,"abstract":"Dichloroacetonitrile (DCAN) is a highly toxic nitrogenous byproduct formed during UV/monochloramine (UV/NH<ce:inf loc=\"post\">2</ce:inf>Cl) advanced treatment. A common but untested assumption is that increasing precursor concentrations invariably increases DCAN formation. This study challenges that assumption by systematically varying the concentrations of ammonia (NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup>), hypochlorous acid (HOCl), NH<ce:inf loc=\"post\">2</ce:inf>Cl, and a model nitrogen-free organic matter (NFOM, phenol) under UV/NH<ce:inf loc=\"post\">2</ce:inf>Cl. Results show that increasing NH<ce:inf loc=\"post\">2</ce:inf>Cl and/or HOCl promoted DCAN formation, but raising NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup> alone did not enhance DCAN formation and even reduced yield, indicating that NH<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">+</ce:sup> does not act as a direct and efficient nitrogen source under these conditions and may instead compete for oxidants. More surprisingly, increasing phenol concentration reduced the DCAN yield, implying competition among reactive species. When all precursors were increased proportionally at fixed ratios, both the concentration and yield of DCAN increased. Using aspartic acid as a model dissolved organic nitrogen compound, we further show that increasing total nitrogen concentration enhanced DCAN formation but did not increase DCAN yield. To facilitate practical application, we employed an artificial intelligence (AI) agent to build models that simulate DCAN formation (R<ce:sup loc=\"post\">2</ce:sup> = 0.9175) and yield (R<ce:sup loc=\"post\">2</ce:sup> = 0.954) well, and put it in an open web platform (<ce:inter-ref xlink:href=\"https://dcan-formation.netlify.app/\" xlink:type=\"simple\">https://dcan-formation.netlify.app/</ce:inter-ref>). Collectively, these findings challenge conventional assumptions that all precursors contribute positively and additively to DBP formation, and highlight the use of AI in scientific explorations.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"10 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Potential of foaming events in reshaping vertical distribution of waterborne antibiotic-resistant human pathogens and signaling public health risks in surface waters","authors":"Ming Zhang, Jiayuan Liu, Yucheng Shen, Jian Chen, Jiahao Li, Qunkai Fang, Jinying Huang, Shicheng Zhang, Zhuochen Shao, Junchao Yang, Yongming Luo, Daoyong Zhang, Duman Imanmadi, Xiangliang Pan","doi":"10.1016/j.watres.2026.127268","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127268","url":null,"abstract":"While pathogens in surface waters frequently cause epidemic outbreaks and millions of annual deaths worldwide, their association with natural aqueous foaming, a common yet overlooked phenomenon, remains unexplored. This study investigated whether foaming is associated with changes in the distribution and potential risk of antibiotic-resistant human pathogens (ARHPB) in surface waters, challenging the traditional view that sediments are the primary sink for waterborne pathogens. The surface foam layer was found to coincide with selective transport of bacteria (particularly, the potential priority multidrug-resistant genera like <ce:italic>Acinetobacter</ce:italic> and <ce:italic>Enterobacter</ce:italic>) from benthic sediments into the water column via bubble adhesion, a mechanism linked to the bacterial virulence trait of motility. Meanwhile, bacteriophages were predominantly distributed in the water column, where genes associated with immune modulation were more abundant. Metagenomic analysis reveals that the relative abundance of potential human-pathogenic bacteria harboring co-localized antibiotic resistance genes and mobile genetic elements was greater in the water column during foaming (from near-zero to markedly higher levels) than under unfoamed conditions, suggesting enhanced potential for horizontal gene transfer. However, foamed and unfoamed samples were collected in July and October, respectively, and the temporal confound prevented causal attribution to foaming alone. Nevertheless, consistent patterns across four independent water bodies indicate that foaming events are among the covarying factors for the elevated potential ARHPB relative abundance and deserve further exploration as potential sentinels for public health risks. Inclusion of foam monitoring in aquatic risk assessment frameworks warrants consideration, pending prospective validation.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"18 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Isolation of Dehalococcoides mccartyi JC20 and Genome-Centric Metatranscriptomic Identification of Aminivibrio sp. as a Candidate Vitamin B12 Producer","authors":"Xin Yu, Zhiming Wu, Guiping Liu, Lianglu Wang, Lanhua Wang, Jinyan Liu, Zijin Bian, Xuya Wu, Jiandong Jiang, Wenjing Qiao","doi":"10.1016/j.watres.2026.127267","DOIUrl":"https://doi.org/10.1016/j.watres.2026.127267","url":null,"abstract":"Vitamin B<ce:inf loc=\"post\">12</ce:inf> is an essential cofactor for reductive dehalogenases, yet many organohalide-respiring bacteria, including <ce:italic>Dehalococcoides mccartyi</ce:italic>, are B<ce:inf loc=\"post\">12</ce:inf>-auxotrophic and rely on syntrophic partners for B<ce:inf loc=\"post\">12</ce:inf> supply. Here, we used genome-centric metatranscriptomics to investigate the B<ce:inf loc=\"post\">12</ce:inf>-cross-feeding network sustaining 1,2-dichloroethane dechlorination in a defined enrichment consortium. Sustained dechlorination proceeded in both B<ce:inf loc=\"post\">12</ce:inf>-free (with other vitamins retained) and completely vitamin‑free treatments at rates of 10.03 ± 0.73 and 9.66 ± 0.05 μM Cl<ce:sup loc=\"post\">-</ce:sup> released·day<ce:sup loc=\"post\">-1</ce:sup>, respectively, with B<ce:inf loc=\"post\">12</ce:inf> detected at 1.7-3.3 µg∙L<ce:sup loc=\"post\">-1</ce:sup> after successive transfers. Metagenomic and metatranscriptomic analyses revealed that <ce:italic>Aminivibrio</ce:italic> possesses a complete <ce:italic>de novo</ce:italic> B<ce:inf loc=\"post\">12</ce:inf> biosynthesis pathway, which was significantly upregulated 123.38-fold under B<ce:inf loc=\"post\">12</ce:inf>-limited conditions, substantially higher than the 7.98-fold upregulation observed in the established B<ce:inf loc=\"post\">12</ce:inf> producer <ce:italic>Acetobacterium</ce:italic>. In response to B<ce:inf loc=\"post\">12</ce:inf> deprivation, <ce:italic>D. mccartyi</ce:italic> significantly upregulated its B<ce:inf loc=\"post\">12</ce:inf> transporter operon (<ce:italic>btuFCD</ce:italic>) and sustained dechlorination via the reductive dehalogenase TceA. Most recovered MAGs were fermentative bacteria that supplied acetate and hydrogen to <ce:italic>D. mccartyi</ce:italic>. A pure strain of <ce:italic>D. mccartyi</ce:italic>, designated JC20, was further isolated by dilution-to-extinction and achieved cell densities of 10<ce:sup loc=\"post\">9</ce:sup> cells∙mL<ce:sup loc=\"post\">-1</ce:sup>. Collectively, these findings identify the fermentative <ce:italic>Aminivibrio</ce:italic> as a previously unrecognized candidate for B<ce:inf loc=\"post\">12</ce:inf> production and highlight its potential role in supporting <ce:italic>Dehalococcoides</ce:italic>-mediated dechlorination. This work expands our understanding of the diversity of B<ce:inf loc=\"post\">12</ce:inf>-producing partners in organohalide‑respiring communities and provides insights into the microbial interactions underpinning bioremediation in oligotrophic contaminated environments.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"3 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2026-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149374235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}