The presence of the Enterobacter cloacae complex (ECC) in natural water bodies poses potential public health risks because these bacteria can enter humans from the environment within the “One Health” framework. Nevertheless, there is a notable deficiency in the isolation and knowledge of carbapenem- and polymyxin-resistant ECC strains from natural water bodies. In this research, 48 ECC strains were isolated from natural water bodies. Of these, eight strains were resistant to carbapenems (imipenem) and polymyxins (polymyxin B and colistin sulfate) and were classified as multi-locus sequence typing 13. Comparative genomic analysis identified bla_CMY-63, pmrE, pmrF, and various efflux pump genes as key genetic determinants of co-resistance to carbapenems and polymyxins. Notably, these strains exhibited relatively high virulence, with cell death rates ranging from 57% to 84%. They also exhibited virulence against Galleria mellonella. This research sheds light on the potential health risks of carbapenem- and polymyxin-resistant ECC strains displaying virulence in natural water bodies.

Ultraviolet (UV) disinfection is widely used in water purification due to its high efficiency and safety. This study investigated the effect of varies UV intensity on bacterial disinfection at 254 nm. At a constant UV dose of 10 mJ/cm², the inactivation rate of Escherichia coli increases significantly from 0.5-log at 0.5 mW/cm² to 7.2-log at 10 mW/cm² with increasing UV intensity. Fitting the disinfection data to the Chick-Watson model, expressed as Inactivation rate= (k'/ln10)×Iⁿ×t= (k'/ln10)×I^n-1×D, revealed that the exponent n, representing the weighting effect of UV intensity, was consistently greater than 1. This finding indicates that increasing UV intensity is more effective for bacterial inactivation than simply extending exposure time. Photoreactivation experiments demonstrated that higher UV intensities led to reduced regrowth, with almost complete suppression observed at 10 mW/cm². Fluorescent staining, scanning electron microscopy, and selective culture experiments demonstrated that high-intensity UV accelerated membrane damage, resulting in increased numbers of both lethally and sublethally damaged cells. Prokaryotic transcriptome analysis revealed significant downregulation of repair-related pathways and upregulation of pathways associated with programmed cell death. Electron paramagnetic resonance analysis confirmed that elevated singlet oxygen levels contributed to cellular damage, complementing the direct effects of UV irradiation. These findings indicate that increasing UV intensity enhances bacterial inactivation not only by intensifying physical damage but also by disrupting repair mechanisms and inducing oxidative stress, thereby improving disinfection efficiency, which enhances the effectiveness of UV-based bacterial disinfection processes.

The removal of bisphenol A (BPA) in seawater using microalgae is still a challenge due to the low removal efficiency and weak tolerance. A novel Oocystis algal strain was isolated for BPA removal with an efficiency (> 98%) over two times higher than that of the common microalgae Chlorella (42.8%). The maximal carbon capture rate of Oocystis was 0.16 g/(L·d) which was much higher than that of Chlorella (0.06 g/(L·d)). The BPA removal fitted a first-order kinetic model and Oocystis showed a maximum removal rate of 29.80 μg/(L·d) at a BPA concentration of 2000 μg/L. The new Oocystis strain had a wide range of pH adaptability for BPA removal. The sharp increase in peroxidase (POD) activity indicated its involvement in BPA degradation. Transcriptome analysis showed that BPA mainly affected the photosynthesis-related genes while the engagement of glutathione POD in the BPA biodegradation was confirmed. BPA could also serve as growth promoter for Oocystis during the removal process, which subsequently enhanced the growth and carbon capture. BPA could be removed by the Oocystis strain through hydroxylation, demethylation, and conjugation. The Oocystis strain still maintained high BPA removal efficiency (100%) and carbon capture rate (0.2 g/(L·d)) in the pilot-scale tailwater treatment system, illustrating microalgal processes were efficient for marine pollution control. This study also provides new ideas for developing low-cost carbon capture technologies to achieve the goal of carbon neutrality.

The synergistic reduction of wastewater greenhouse gases (GHGs) and pollutants presents a critical environmental challenge. Understanding the synergistic efficiency and the factors that influence it is crucial for informed policy-making, but methods for assessing this efficiency are currently lacking. This study evaluates the synergistic efficiency in China from 2009 to 2019 using the elastic coefficient method, and assesses strict water policy impacts using double machine learning (DML). Results indicate that before 2015, China experiences synergistic increases, which shift to non-synergistic following the implementation of a strict water policy in 2015. Despite improved wastewater treatment rates, this policy paradoxically increases GHG emission intensity, leading to a “water-carbon” contradiction, especially in water-scarce, poorly enforced, and underdeveloped regions. The policy effect on GHG emission intensity is most influenced by wastewater pipeline infrastructure, followed by socioeconomic development, technological innovation, and industrial structure. Inefficiencies in GHG emission reductions are due to expanded wastewater treatment facilities and lower industrial energy efficiency. Conversely, higher salaries and technological advancements facilitate emission reductions. To achieve the synergy of effluent pollution and GHG reduction in the wastewater sector, provincial control priorities into four patterns are explored. This study provides guidance for low-carbon retrofitting of existing wastewater treatment plants and informs the design of effective water policies.

Soil microplastics (MPs) are a growing environmental concern with substantial implications for soil ecosystems, agricultural productivity, and human health. Extensive research has been conducted on the sources, transport, distribution, environmental risks, and toxic effects of soil MPs. However, research on soil MPs remains inconsistent and incomplete, and few reviews have provided a comprehensive global perspective on the key challenges in this field. In response, we compiled and analyzed baseline data from 152 studies, and conducted a comprehensive review of the literature on soil MPs. We identified key challenges in four critical areas: extraction methods, data reporting, spatial distribution characteristics, and environmental criteria. Additionally, we provided targeted recommendations: 1) establishment of standardized methods and processes for extracting soil MPs; 2) development of standardized guidelines for describing MPs and soil properties, along with an expansion of research into MP-derived pollutants and use of environmentally relevant MP materials; 3) expansion of soil MP research to socioeconomically vulnerable and ecologically sensitive regions, diverse land use types, and deeper soil layers; and 4) an approach to derive environmental quality criteria for soil MPs, based on human exposure risks. By establishing research standards and broadening the scope of soil MP studies, we aim to enhance global understanding and inform strategies for mitigating soil MP pollution.

It is of critical importance to determine the endpoint of stabilization for landfills that are stabilized by aeration acceleration. Current stabilization evaluation methods are inconsistent and mostly fail to account for the effect of oxygen concentration. In this study, degradation experiments were conducted to quantitatively analyze the impact of oxygen on microbial communities and metabolic functions. High-throughput sequencing analysis demonstrated that an oxygen concentration exceeding 10% significantly enhances amino acid metabolism, secondary metabolite biosynthesis, and exogenous biodegradation. Three-dimensional fluorescence data were analyzed using the PARAFAC method, and a novel fluorescence-based stabilization indicator was proposed based on the ratio of fulvic-like to tyrosine-like substances. When the growth multiples of the fluorescence index exceed 10-fold, it can be inferred that degradation has been met the stabilization endpoint. Principal component analysis was employed to establish multiple regression equations between the physicochemical parameters of landfill waste and dissolved fluorescent substants, offering an innovative insight to evaluate the stabilization process of aerated landfills.

As a typical nonsteroidal anti-inflammatory drug, a significant amount of ibuprofen (IBP) can not be adsorbed by the human body and thus enters the environment, posing potential risks. Biochar (BC) adsorption is low-cost and easy to implement and is a potential technology for the removal of IBPs from water. To the best of our knowledge, the adsorption mechanism of IBP on BC is unclear, and certain physiochemical properties, such as low porosity, limit the adsorption capacity of IBP. In this study, a novel synthesis strategy involving the loading of nitrogen-rich polyaniline (PANI) particles is proposed to improve porosity and increase surface functional groups. A PANI/acid-impregnated reed BC (PANI/H-BC) composite was prepared through in-situ polymerization using reed BC synthesized via rapid pyrolysis. Adsorption experiments revealed that PANI/H-BC has a maximum adsorption capacity of 35.58 mg/g, which is 4.3 times and 3.7 times greater than those of PANI and BC, respectively. Besides, PANI/H-BC reached adsorption equilibrium within 30 min, reflecting a reduction of 50% compared to BC. It retains a significant adsorption capacity after ten cycles and is reusable. Moreover, the physical and chemical properties of PANI/H-BC were characterized, and the enhanced adsorption performance was demonstrated to be the result of multiple mechanisms, including π‒π conjugation, hydrogen bonding and electrostatic interactions. These findings offer theoretical support for the adsorption and removal of IBPs as well as optimization of BC adsorbents. Production cost assessment and comparison, including industrial factors, were conducted. The low cost and renewability underscore its significant potential in practical applications.

Benthic biofilms, the aggregates of multi-trophic microorganisms, play an important role in nitrogen cycling in aquatic ecosystems and are significantly influenced by flow velocity. Nevertheless, the roles of multi-trophic microbial communities in nitrogen cycling of benthic biofilms remain unclear, especially under flow velocity conditions. In this study, we investigated how low trophic level microbial communities (bacteria, fungi, and algae), primary predator (protozoa) and secondary predator (metazoan) mediate the nitrogen cycling in benthic biofilms under low (0.05 m/s) moderate (0.1 m/s) and high (0.15 m/s) flow velocity conditions. The results showed that the activities of ammonia monooxygenase, nitrate reductase and nitrite reductase in benthic biofilms under high flow velocity increased 26.32%, 18.66%, and 10.46%, respectively, compared with those under low flow velocity. Metagenomic sequencing analysis indicated that high flow velocity enhanced the relative abundances of functional genes involved in nitrification (amoABC) and denitrification (narG, nirK, and nirS). Compared with other trophic level microorganisms, the bacterial richness had the highest explanation (42.36%) for the variation in ammonia monooxygenase, and the variations in activities of nitrate reductase and nitrite reductase were explained 33.29% and 36.68% by protozoan richness, respectively. High richness index might promote nitrification and denitrification process via upregulating amino acid transport and metabolism, and signal transduction mechanisms.The negative cross trophic associations (potential predation activity) enhanced nitrification and denitrification by promoting microbial activity further enhancing ATPase activity and potential electron donor production. This study provides a new understanding of how multi-trophic microorganisms regulate the nitrogen cycling in benthic biofilms under increased flow velocity, which will benefit river management.

Extremely toxic cyanide-contaminated wastewater discharged from steel industries poses serious environmental and health risks. Cyanide removal through physical and chemical treatments has cost-intensive operational challenges. Microbial bioremediation is cost-effective and environment friendly. As microorganisms can degrade cyanide by utilizing it as a source of nitrogen and converting it into less toxic compounds such as ammonia, this study was planned to get metagenomic data first and then potential microbial strains from the contaminated samples. In this study, wastewater samples from the equalizer and the sludge thickener tank of a steel wastewater treatment plant showed high cyanide concentration (mg/L) of 21.6 and 27.59, respectively. The free form of cyanide was predominant as the wastewater pH was ≥ 9. The contents of anions (F^–, Cl^–, NO₂^–, Br^–, NO₃^–, SO₄^2–) and elements (Na, Al, K, Fe) were also on the higher side. The metagenomic study revealed microbial community structure and taxonomic abundance with dominance of cyanide-degrading bacterial genera in the wastewaters, viz., Bordetella, Achromobacter, Pseudomonas, and Burkholderia, providing an opportunity to screen and obtain the efficient CN-degrading strains. Bacteria belonging to the phylum Deinococcus and the genus Mesorhizobium were reported for the first time from cyanide-contaminated water. Also, functional analysis showed high prevalence of genes encoding enzymes critical to cyanide degradation pathways e.g., rhodanese, nitrilase, nitrile hydratase, amidase, cyanide-insensitive terminal oxidase, and malate:quinone oxidoreductase. Eight distinct alkaliphilic cyanotropic microorganisms were successfully isolated and shown to degrade cyanide effectively at pH 9.5, indicating their metabolic adaptation to cyanide toxicity and alkaline stress. These findings can lead to a microbial technology against cyanide contamination.

Spent lead paste (SLP) presents a major recycling challenge in lead-acid battery treatment due to its insoluble lead compounds. This study develops an innovative and environmentally sustainable approach by integrating (NH₄)₂SO₄-NH₃·H₂O with suspension electrolysis, effectively converting poorly soluble PbSO₄ into soluble [Pb(NH₃)₄]²⁺ complexes. The electrolytic conversion mechanisms of SLP components are systematically elucidated, revealing four distinct transformation pathways: 1) metallic Pb undergoes complete dissolution as [Pb(NH₃)₄]²⁺ complexes followed by cathodic reduction to elemental lead; 2) PbO₂ increases after suspension electrolysis since part of PbO is oxidized; 3) PbO demonstrates dual behavior, with 45.74% undergoing anodic oxidation to PbO₂ while the remainder (54.26%) participates in cathodic electrodeposition; 4) PbSO₄ exhibits triple conversion routes, including: 1) 32.98% transformation through intermediate (NH₄)Pb(OH)SO₄ formation followed by anodic conversion to PbO·PbSO₄, 2) 21.36% direct cathodic reduction to metallic lead, and 3) the residual fraction maintaining soluble [Pb(NH₃)₄]²⁺ speciation in the electrolyte. The optimized process achieves exceptional current efficiency (95.49%) and lead recovery (45.67%), with anode residues comprising 67.58% PbO₂ and 32.42% PbO·PbSO₄. Remarkably, this process exhibits significant economic and environmental advantages, with recycling 1 kg of SLP through the (NH₄)₂SO₄-NH₃·H₂O suspension electrolysis process resulting in a net profit of 0.3466 USD and a reduction in carbon emissions of 119.758 kg CO₂ eq., offering dual advantages of environmental and economic benefits. This work provides fundamental insights into lead phase conversion during suspension electrolysis while presenting a practical, effective solution for battery recycling industries.

The stable operation of membrane bioreactors (MBRs) strongly depends on the extent of membrane fouling. Phages are gaining recognition as ideal and sustainable biological agents for mitigating membrane fouling, but the limited understanding of phage composition, function profiles, and their relationship with actual membrane fouling behavior greatly constrains engineering applications. This study demonstrated the critical role of phage-bacterium interactions in both the formation and mitigation of fouling in anaerobic membrane bioreactors (AnMBRs). Firstly, phages within the fouling layers exhibited greater diversity than those in sludge. Lytic phages in the fouling layers target ~42% of the top 100 most abundant species and biofilm-forming bacteria. In addition, adverse conditions caused by high transmembrane pressure (TMP) and the presence of harmful substances in sewage triggered prophage activation; notably, 19.1%–26.3% of contigs in the gel layer contained prophages, a 3.2- to 5.3-fold higher compared to sludge (3.6%–6.1%). These findings underscored the potential role of the phage lysis cycle in alleviating membrane fouling. Phage-encoded auxiliary metabolic genes (AMGs; 138 types in total) related to fouling formation, bacterial integrity, and stress tolerance were identified, potentially enhancing fouling stability. Conversely, phage-encoded AMGs associated with polysaccharide and protein degradation may promoted biofilm breakdown, and the combined lysis cycle further alleviate membrane fouling. Overall, this study revealed, for the first time, the potential role of phages in both the formation and mitigation of membrane fouling in AnMBRs, and provided theoretical support for phage therapy in controlling membrane fouling.

The efficacy of DNA sequencing, particularly long reads nanopore sequencing, is critically dependent on the amount and quality of the input DNA. However, extracting high concentrations of DNA from low biomass samples, especially from solid matrices, presents significant challenges, this limitation not only substantially hampers the scope of environmental microbiology studies but also makes enhancing DNA yield indispensable in many instances. Therefore, in this study, we systematically evaluated the impact of four different DNA enrichment methods on both amplicon and metagenomic community analyses of solid-phase, low-biomass samples: permafrost soil and biofilm of sand filter. These methods include multiple displacement amplification (MDA), centrifugal filtration (CF), freeze vacuum drying at (FVD) as well as vacuum centrifugal at 35, 45, and 60 °C (namely VC35, VC45, VC60). Our results indicate that FVD was the most effective for increasing DNA concentration, while VC methods best preserved DNA fragment length. In contrast, the widely used MDA and CF methods exhibited biases, preferentially enriching low-GC content sequences, which affected both assembly and annotation outcomes. Metagenomic assembly from MDA and CF samples was suboptimal, with fewer contigs and no middle quality MAGs recovered compared to other methods. Community composition analysis revealed significant shifts across all enrichment methods, with Sphingomonas and Sphingorhabdus genera could be obviously enriched. These findings highlight the necessity and importance of carefully selecting DNA enrichment methods to ensure reliable metagenomic investigation of low-biomass environmental samples.

Antimicrobial resistance (AMR) poses a significant threat to public health and is increasingly recognized within the “One Health” framework, which emphasizes the interconnectedness of human, animal, and environmental health. While extensive research has focused on regulating antibiotic use across healthcare and other sectors, the impact of intensive biocide use on AMR development, particularly in seawater-cooled systems, remains underexplored. In this study, we report the isolation and characterization of a multidrug-resistant Klebsiella quasipneumoniae strain from the cooling water system of a coastal power plant, where continuous chlorination at 0.2 ppm is employed for biofouling control. The isolated strain displayed broad-spectrum resistance to multiple biocides and antibiotics. Interestingly, the strain shown enhances biofilm formation in response to biocides and antibiotics, thereby compounding its resistance profile. Efflux assays with ethidium bromide (EtBr) and whole-genome sequencing revealed that efflux pumps are central to the resistance mechanisms. Additionally, the presence of β-lactamase (OKP-A) and FosA genes confers resistance to the β-lactam and epoxide classes of antibiotics. The strain was found to be salt-tolerant and preferred to grow at normal salinity, indicating a non-marine origin of this isolate. These findings highlight the prevalence of biocide and antibiotic-resistant pathogens in marine cooling water systems that primarily rely on biocides for biofouling control. In line with One Health principles, our research advocates for a reassessment of biocide practices in marine cooling water systems and the implementation of proactive measures to mitigate the spread of antimicrobial resistance (AMR).

Microplastics, as emerging environmental pollutants, are ubiquitously distributed across aquatic, terrestrial, and atmospheric systems, where their heterogeneous spatiotemporal dynamics are governed by multifactorial interactions. The key drivers include the intrinsic properties of microplastics (size, shape, and aging state), environmental physical parameters (hydrological factors, soil structure, meteorological factors, lighting and temperature), chemical factors (pH, inorganic iron, and organic matter), and biological activities (microorganisms and root organisms). These interconnected factors collectively dictate MP transport pathways, retention hotspots, and long-term ecological trajectories. Despite the increasing recognition of the environmental prevalence of microplastics, critical knowledge gaps persist regarding the synergistic mechanisms underlying their cross-media migration and fate. This review synthesizes current insights into the complex interplay of factors influencing MP behavior, with a focus on bridging the mechanistic understanding and real-world scenarios. By establishing a unified framework for the environmental interactions of microplastics, this work advances predictive modeling capabilities and informs targeted strategies for pollution mitigation and ecosystem protection, ultimately supporting robust risk assessment protocols.