Shifting from biotic to abiotic drivers of
urban microbial multifunctionality under
drought and rehydration
image:
Response of overall C, N, P, and S cycling functions and urban microbial multifunctionality to the drought–rehydration cycle in an urban grass ecosystem
view moreCredit: ©Science China Press
Climate change has intensified the frequency and severity of urban droughts, exposing green spaces to extreme water shortages. These events disrupt plant-microbe interactions and ecosystem functions. Extensive research has focused on the role of microbiomes in agricultural and natural ecosystems. However, understanding the dynamic regulation during drought and subsequent recovery is crucial for maintaining urban ecosystem resilience. The shift and regulatory drivers remain particularly underexplored.
Qin-Lin Chen’s group at Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, conducted microcosm experiments using Zoysia japonica, a common urban turfgrass. The team simulated four drought intensities and recovery by rehydration. Integrating omics technologies and soil enzyme stoichiometry, they analyzed alteration in microbial communities and biochemical cycling associated with carbon, nitrogen, phosphorus, and sulfur to pinpoint the drivers of urban microbial multifunctionality.
The results demonstrated that drought intensities reshaped the composition of bacteria and fungi across the rhizosphere and phyllosphere. Unexpectedly, drought enhanced microbial multifunctionality by significantly boosting 21 microbial functional potentials, including carbon fixation and denitrification. Upon rehydration, urban microbial multifunctionality largely returned to the control levels. However, legacy effects of extreme drought persisted in specific functions, notably phyllosphere organic nitrogen mineralization.
A key insight from the study was the distinct regime shift observed between drought and subsequent recovery. The analysis indicated that biotic factors, particularly rhizosphere bacteria and fungi, directly drove microbial multifunctionality during the drought phase. However, rehydration marked a transition. Soil physicochemical properties, specifically pH and ammonium nitrogen (NH4+-N), emerged as the main direct drivers of stabilized ecosystem functions.
The study underscores a regulatory shift. Microbes defend ecosystem functions during drought shock, while soil properties dominant the recovery stages. Effective management requires a dual focus on biology and abiotic factors. Combining drought-resilient plants with precise management of soil physicochemical conditions is essential for rapid ecosystem recovery in urban environments.
See the article:
Shift from biotic to abiotic drivers of urban microbial multifunctionality under drought and rehydration.
Journal
Science China Life Sciences
DOI
Tiny vesicles, big risk: Environmental sweeteners trigger antibiotic resistance transfer
Chinese Society for Environmental Sciences
image:
Increasing diversity of artificial sweeteners stimulates a subset of soil bacteria to activate extracellular vesicle (EV) biogenesis pathways. These vesicles selectively package and release antibiotic resistance genes (ARGs), leading to elevated resistance abundance and enhanced dissemination risk without major disruption of overall microbial community structure. EV-producing microbes are characterized by larger genomes, lower GC content, and enriched stress-adaptation functions, collectively facilitating vesicle-mediated gene transfer and hidden resistome expansion in soil ecosystems.
view moreCredit: Environmental Science and Ecotechnology
Antibiotic resistance is widely linked to antibiotic misuse, yet growing evidence suggests that everyday environmental chemicals may also accelerate its spread. A new study reveals that mixtures of artificial sweeteners can stimulate soil bacteria to release microscopic extracellular vesicles that carry antibiotic resistance genes (ARGs). Crucially, sweetener exposure increases the abundance of ARGs within these vesicles, even when the overall composition of the microbial community remains unchanged. These nanoscale particles act as protected biological packages, enabling resistance traits to move efficiently between microbes. The research demonstrates that increasing chemical diversity—not just concentration—can intensify resistance dissemination through previously overlooked pathways. By uncovering extracellular vesicles as hidden hub of gene transfer, the study reshapes how environmental pollution is understood in relation to global antimicrobial resistance risks.
Antimicrobial resistance is projected to cause millions of deaths annually by mid-century, largely due to the spread of ARGs among bacteria. While antibiotic overuse remains a major driver, non-antibiotic pollutants are increasingly recognized as hidden contributors. Artificial sweeteners, widely consumed and environmentally persistent, accumulate in soils and waters where they exert subtle stress on microbial communities. Previous studies mainly examined single compounds, despite real environments containing complex mixtures of pollutants. Meanwhile, extracellular vesicles—tiny membrane-bound particles released by bacteria—have emerged as powerful carriers of genetic material capable of long-distance transfer. In the context of antimicrobial resistance, deeper investigation into how pollutant diversity influences vesicle-mediated resistance dissemination is urgently needed.
Researchers from the Institute of Urban Environment, Chinese Academy of Sciences, together with collaborators in Germany, reported (DOI: 10.1016/j.ese.2026.100681) on February 27, 2026, in Environmental Science and Ecotechnology that artificial sweetener diversity can significantly enhance the spread of antibiotic resistance genes in soil ecosystems. Using controlled soil exposure experiments combined with metagenomics and microbial assays, the team demonstrated that environmental stress caused by mixed sweeteners stimulates bacteria to produce extracellular vesicles enriched with antibiotic resistance genes, enabling genetic transfer to previously sensitive bacteria and increasing resistance risk beyond traditional ecological indicators.
To simulate realistic environmental conditions, the researchers exposed agricultural soils to increasing combinations of seven commonly detected artificial sweeteners while maintaining constant total concentrations. Advanced metagenomic sequencing revealed a striking pattern: although the overall soil microbiome changed little, extracellular vesicles responded dramatically. Vesicle-associated microbial populations shifted in more than 30% of detected genera, indicating that stress responses were concentrated in specific bacterial subgroups rather than across entire communities.
These vesicles contained over one hundred antibiotic resistance gene subtypes, including multidrug and β-lactam resistance genes. Notably, resistance abundance increased significantly with sweetener diversity, even when microbial community composition remained stable. Functional analyses showed enrichment of stress-response pathways, DNA repair systems, membrane transport mechanisms, and quorum-sensing functions—traits linked to microbial adaptation under environmental pressure.
Laboratory co-culture experiments provided direct evidence of biological impact. Vesicles isolated from high-diversity treatments successfully transferred resistance traits to Escherichia coli, increasing survival under antibiotic exposure. Genomic reconstruction further identified key vesicle-producing bacteria belonging mainly to the Pseudomonadota lineage, organisms characterized by larger genomes and strong stress-response capacity. These microbes appear to act as transmission hubs, selectively packaging resistance genes into vesicles that function as mobile genetic delivery systems. Together, the findings reveal a previously hidden decoupling: environmental stress can accelerate resistance spread without visibly disrupting microbial ecosystems.
According to the researchers, extracellular vesicles may represent an overlooked early-warning signal in environmental health monitoring. Because vesicles respond rapidly to stress and travel more easily than whole cells, they can disseminate resistance genes across ecosystems before conventional indicators detect change. The team emphasized that pollutant diversity—not simply pollutant concentration—plays a decisive role in shaping microbial evolution. Recognizing vesicle-mediated gene transfer could therefore improve risk assessment frameworks and help explain why resistance sometimes expands unexpectedly in environments lacking direct antibiotic exposure.
The discovery carries important implications for environmental management and the One Health framework linking ecosystems, agriculture, and human health. Artificial sweeteners are widely used worldwide and often considered biologically harmless, yet their combined presence may unintentionally accelerate resistance evolution. Because extracellular vesicles protect genetic material and travel efficiently through soils and water, they may bridge environmental and clinical resistance reservoirs. Incorporating vesicle monitoring into pollution assessment and antimicrobial surveillance systems could enable earlier detection of emerging risks. More broadly, the study highlights the need for environmental policies that evaluate chemical mixtures rather than single contaminants, offering new strategies to slow the global spread of antimicrobial resistance.
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References
DOI
Original Source URL
https://doi.org/10.1016/j.ese.2026.100681
Funding information
This study was supported by the National Key Research and Development Program of China (2024YFE0106300), National Natural Science Foundation of China (42407165), Fujian Provincial Natural Science Foundation of China (2023J02031), China Postdoctoral Science Foundation (2024M753157, 2024T170898), Postdoctoral Fellowship Program of CPSF (GZC20232577), Youth Innovation Promotion Association, Chinese Academy of Sciences (2023321), and Ningbo Yongjiang Talent Project (2022A-163-G).
About Environmental Science and Ecotechnology
Environmental Science and Ecotechnology (ISSN 2666-4984) is an international, peer-reviewed, and open-access journal published by Elsevier. The journal publishes significant views and research across the full spectrum of ecology and environmental sciences, such as climate change, sustainability, biodiversity conservation, environment & health, green catalysis/processing for pollution control, and AI-driven environmental engineering. The latest impact factor of ESE is 14.3, according to the Journal Citation ReportsTM 2024.
Journal
Environmental Science and Ecotechnology
Subject of Research
Not applicable
Article Title
Extracellular vesicles drive stress-induced antibiotic resistance spread in soil
A radical solution: Persistent phenoxyl chemistry accelerates antibiotic degradation
Chinese Society for Environmental Sciences
image:
Schematic comparison between conventional oxidation and contaminant-assisted synergistic oxidation. In the baseline Mn(VII)/chlorite system, short-lived manganese intermediates lead to limited pollutant removal. In contrast, phenolic compounds undergo proton-coupled electron transfer to generate long-lived phenoxyl radicals, which act as persistent reactive mediators and accelerate sulfamethoxazole (SMX) degradation by 3.5–20 times. This mechanism transforms phenolic pollutants from inhibitory matrix components into active promoters of water purification.
view moreCredit: Environmental Science and Ecotechnology
Water treatment technologies traditionally assume that coexisting pollutants interfere with each other, reducing cleanup efficiency. A new study overturns this long-standing assumption by revealing that certain phenolic contaminants can actively accelerate the degradation of antibiotics rather than hinder it. Researchers discovered that phenolic compounds transform into persistent phenoxyl radicals that act as long-lived reactive mediators, dramatically enhancing pollutant removal. In an oxidation system combining permanganate and chlorite, these radicals increased antibiotic degradation rates by up to twentyfold. The findings introduce a new concept in environmental remediation: instead of eliminating all contaminants individually, interactions among pollutants themselves can be strategically harnessed to improve water purification performance.
Emerging contaminants such as antibiotics and persistent organic pollutants increasingly threaten global water security and public health. Advanced oxidation processes are widely used to degrade these chemicals by generating highly reactive species, yet their effectiveness often declines in real wastewater because multiple contaminants compete for reactive intermediates. Phenolic compounds—common industrial and environmental pollutants—are usually regarded as problematic matrix components that suppress treatment efficiency. However, isolated observations have hinted that pollutant interactions might sometimes produce unexpected positive effects. Whether such cooperation can be systematically understood and controlled has remained unclear. Based on these challenges, deeper investigation into how coexisting contaminants interact during oxidation processes became necessary.
Researchers from Sichuan University and collaborating institutions reported the findings (DOI: 10.1016/j.ese.2026.100680) in Environmental Science and Ecotechnology (Available online 27 February 2026). The study investigated how phenolic contaminants influence antibiotic removal within a permanganate/chlorite oxidation system. Using sulfamethoxazole as a model antibiotic, the team demonstrated that phenolic compounds fundamentally reshape reaction pathways, generating stable radical intermediates that dramatically accelerate degradation. The work combines experimental chemistry, spectroscopy, and theoretical modeling to reveal a previously unrecognized contaminant-assisted oxidation mechanism that improves treatment performance in complex water systems
The researchers first evaluated how different coexisting pollutants affect antibiotic degradation. Most contaminants inhibited removal, as expected from competitive reactions. Surprisingly, phenolic compounds produced the opposite effect: sulfamethoxazole removal increased from roughly 15% to nearly complete degradation within minutes under optimized conditions.
Mechanistic experiments revealed that the enhancement was not caused by conventional reactive oxygen species. Instead, phenolic molecules underwent proton-coupled electron transfer reactions with permanganate and chlorite, forming long-lived phenoxyl radicals. Unlike short-lived oxidants, these radicals persisted after the initial reaction stage and continued degrading antibiotics independently.
Advanced spectroscopic trapping experiments confirmed the presence of phenoxyl radicals, while inhibition tests showed that removing them halted degradation entirely. Computational modeling further demonstrated that hydrogen-bond-mediated electron transfer drives radical formation, explaining why only certain phenolic structures produce strong acceleration effects.
Importantly, the radicals displayed selective behavior: they preferentially attacked amino-containing antibiotics through electron transfer followed by radical–radical coupling reactions. Their activity correlated with pollutant hydrophobicity, revealing an unusual selectivity mechanism rarely observed in inorganic oxidation systems. Moreover, the radicals remained effective even in real water matrices containing inorganic ions and natural organic matter, highlighting strong resistance to environmental interference.
According to the research team, the study challenges the traditional view that contaminant coexistence is always detrimental to water treatment. By demonstrating that phenolic pollutants can function as reactive mediators, the work introduces a paradigm shift from eliminating interference to engineering beneficial chemical interactions. The researchers emphasize that long-lived phenoxyl radicals combine stability, selectivity, and matrix tolerance—three properties rarely achieved simultaneously in advanced oxidation systems. This insight provides a mechanistic foundation for designing adaptive remediation strategies capable of handling increasingly complex wastewater compositions.
The discovery suggests new opportunities for treating pharmaceutical wastewater, where phenolic byproducts and antibiotics frequently coexist. Instead of removing phenolic compounds beforehand, treatment systems could exploit them to enhance oxidation efficiency through controlled pre-oxidation stages. Such strategies may improve pollutant removal while reducing chemical consumption and operational costs. The findings also support a broader shift toward “self-adaptive” remediation technologies that leverage contaminant networks rather than treating pollutants individually. Future work will focus on pilot-scale testing, process optimization, and intelligent control systems capable of adjusting oxidant dosing under fluctuating wastewater conditions. Ultimately, the study points toward smarter water treatment designs that transform pollution complexity into a functional advantage.
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References
DOI
Original Source URL
https://doi.org/10.1016/j.ese.2026.100680
Funding Information
The authors would like to thank the National Key Research and Development Program of China (2023YFC3210100), National Natural Science Foundation of China (52470107), and Sichuan Science and Technology Program (2023NSFSC1949) for the financial support.
About Environmental Science and Ecotechnology
Environmental Science and Ecotechnology (ISSN 2666-4984) is an international, peer-reviewed, and open-access journal published by Elsevier. The journal publishes significant views and research across the full spectrum of ecology and environmental sciences, such as climate change, sustainability, biodiversity conservation, environment & health, green catalysis/processing for pollution control, and AI-driven environmental engineering. The latest impact factor of ESE is 14.3, according to the Journal Citation ReportsTM 2024.
Journal
Environmental Science and Ecotechnology
Subject of Research
Not applicable
Article Title
Phenolic contaminants generate persistent phenoxyl radicals to accelerate antibiotic degradation
