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Enhancing soil organic carbon (SOC) sequestration is a critical indicator of success in dryland landscape restoration. However, how microbial carbon (C) use efficiency (CUE) regulates microbial necromass C (MNC) formation and its contribution to SOC during long-term biocrust restoration remains unclear. We investigated a biocrust restoration chronosequence (0 (mobile dunes), 15, 25, 38, 44, 61, and 69 yr) in the Tengger Desert, China. CUE metrics (18O-H2O tracing) combined with amino sugar biomarkers were used to elucidate the time-dependent mechanisms of microbial-driven SOC stabilization. Our results showed that biocrust recovery increased SOC contents by 6- to 14-fold relative to mobile dunes. Concurrently, biocrust development ameliorated microhabitat limitations, triggering a 20- to 34-fold in microbial CUE over 15-69 yr, which in turn elevated MNC content by 8- to 10-fold. Crucially, the relative contribution of MNC to the SOC pool was substantial (26.5%-32.2%) during early restoration (15 yr), but this contribution declined to ∼18% in late stages (69 yr), likely owing to the diversification of SOC sources and the reduced net accumulation efficiency of MNC. Furthermore, the SOC pool was consistently dominated by bacterial rather than fungal necromass, highlighting the bacterial C pump as the primary engine for dryland soil C accrual. Overall, these findings indicate that the long-term recovery of biocrust involves an efficient yet capacity-limited microbial C sequestration mechanism, which provides important insights for macro-level dryland management such as parameterizing C models and evaluating ecological restoration outcomes.
Understanding the ecological links in the microbiome of Camellia sinensis is vital for exploring beneficial interactions between microorganisms and economically important woody plants. This study investigates the characteristics of microbial communities, source-sink dynamics, driving factors, and functional differentiation of tea tree bark and bulk soil in the primary tea-producing regions of Yunnan, China (City of Pu'er, Lincang, and Xishuangbanna). Using amplicon sequencing, FEAST source tracking, and functional prediction, we analyzed microbial community differences and ecological roles. Findings revealed that bulk soil may served as the microbial reservoir for bark, sharing all bark bacteria and 68.09% of bark fungi in Pu'er, with minimal reverse flow. Soil harbored higher alpha diversity dominated by Chloroflexi, Acidobacteriota, and Sordariomycetes, while bark selectively enriched Gammaproteobacteria, Cyanobacteriia, and Lecanoromycetes. Plant type mainly influenced bark bacterial communities (R²=76.49%, P < 0.001), whereas geographic location significantly impacted soil bacterial composition (R²=45.72%, P < 0.001) and fungi in both bark (R²=63.06%, P < 0.001) and soil (R²=78.84%, P < 0.01). Total nitrogen (TN) and organic matter (OM) in bulk soil emerged as the predominant factors influencing community variation both for niches of soil and bark. Functional differentiation was observed, with soil microbiomes primarily engaged in chemoheterotrophy and nutrient cycling, while bark microbiomes were more involved in carbon fixation and stress resistance. LEfSe analysis identified 30 bacterial and 64 fungal biomarkers (LDA ≥ 4, P < 0.05), including Xanthobacteraceae in soil and Pleosporaceae in bark. This study highlights soil's crucial role as a microbial reservoir and the impact of niche-specific factors, providing a framework to understand how microbial diversity is maintained and regulated along the Soil-Bark Continuum in tea plants.
This study emphasizes the rarely explored quantitative and qualitative assessments of the microbial contamination influenced by the river floods and the associated human health risks through the application of quantitative microbial risk assessment (QMRA) in the highly flood-prone mid-Brahmaputra valley. Bacterial pathogens were isolated and analyzed through the standard culture and molecular methods. For the entire duration of the study, the pathogens in the studied water sources consistently exceeded the safe limits for both drinking water (0 CFU/100 mL) and recreational water (200 CFU/100 mL), indicating the unsuitability of the water for daily use. The groundwater sources were only found suitable for drinking with pathogenic concentration of 0 CFU/100 mL during the pre-floods of 2023. Escherichia coli was the most prevalent pathogen in the riverine environment studied. The statistical analysis indicated a significant increase in the microbial contaminations and single exposure infection risks (Pinf,single) after floods. Elevated levels of Pinf,single after floods from the exposure of Escherichia coli and Salmonella enterica in river water, and Escherichia coli in both groundwater as well as sediments, exceeded the acceptable risk level of 1 × 10-4. Children were more prone to infections from contaminated sedimental exposure, compared to adults. The results provide a robust quantitative foundation for assessing and monitoring microbial contaminations and associated risks in riverine systems, thereby supporting remediation efforts, strategic planning and mitigation of the public health hazards.
Microbial life can be found in the continental subsurface down to depths of several kilometers, where it may affect mineral-forming and reaction processes. Sulfur isotopes provide an important tool for discriminating between deep microbial activity and abiotic processes. Here, we report the sulfur isotopic composition (δ34S) of pyrite in selenide-rich domains of hematite-carbonate ± selenide veins hosted in black shales from Tilkerode, Harz Mountains (Germany). Framboidal pyrite (PyII) occurs in voids in clausthalite (PbSe) formed by hematite and carbonate dissolution, but is also enclosed in anhedral pyrite (PyIII). Results of secondary-ion mass spectrometry yielded extreme δ34S values ranging from ‒8.5 to + 92.5‰ for PyII, and from ‒40.1 to + 79.1‰ for PyIII. Extreme positive values suggest microbial sulfate reduction (MSR) under closed-system conditions with limited sulfate availability and slow metabolism, and negative values a switch to open-system conditions. All MSR processes most likely occurred after fast uplift of the vein system from about 5 km to 1-2 km depth during Cretaceous-Tertiary reverse faulting, accompanied by cooling from 220 °C to 30-60 °C, as indicated by fluid-inclusion microthermometry and U‒Pb carbonate dating. The results demonstrate that microbial activity at great depth of 0.8 to 1.8 km is possible even in normally toxic Se-Pb-Ag-Hg-rich environments.
Ectomycorrhizal fungi (EMF) play critical roles in nutrient exchange, soil processes, and plant community structure, yet the mechanisms linking their environmental interactions to reproduction remain poorly understood. The black truffle (Tuber melanosporum) provides a model for studying these dynamics through its formation of brûlés-vegetation-free zones around a host plant and associated with fructification. Although prior studies have associated truffle production with factors such as pH, carbonates, and specific microbial groups, most work has been limited by narrow parameter ranges, uncontrolled confounders, and an absence of direct fruiting measurements, leaving unresolved whether these patterns facilitate reproduction or merely accompany it. Here we address these limitations using a broad paired design sampling 93 trees with and without brûlés across productive and unproductive North American orchards. We show that fruiting consistently aligns with distinct soil chemical profiles -including reduced organic matter and nitrogen, and elevated iron and magnesium-and with highly structured microbial communities. Fruiting soils exhibited the highest bacterial and fungal diversity, strong beta-divergence from non-fruiting soils, and enrichment of chemoheterotrophic guilds capable of mobilising nutrients and accelerating organic matter turnover. Network analyses revealed that productive soils support more cohesive and functionally integrated microbial consortia, despite only modest shifts in taxonomic composition. These patterns suggest that T. melanosporum reproduction depends not solely on favourable edaphic conditions, but on active niche construction at the soil chemical-microbial interface. Our findings highlight a previously underappreciated reproductive dimension of EMF ecosystem engineering, with implications for truffle cultivation, sustainable land management, and broader mycorrhizal ecology.
Plastic pollution in natural ecosystems creates novel niches, known as the "Plastisphere", that host heterogeneous microbial communities shaped by substrate type and environmental conditions. This study explored the effects of seasonal variation on the plastisphere evolution on different plastic substrates, oxo-degradable carrier bags (Oxo), oxo-degradable garbage bags (Oxo-G), normal plastics (N), and snack packets (Sn) for 30 days in a microcosm experiment using ambient water from the monsoon-influenced Zuari estuary. The results indicated that the early-stage (day 5) plastisphere was dominated by fast-growing r-strategists, such as Alpha- and Gamma-proteobacteria as well as Campylobacterota-related lineages, whereas mature biofilms (day 30) showed increased abundance of secondary colonisers, including Planctomycetota, Actinomycetota, and Bacteroidota. The oxo-degradable plastics emerged as preferred substrates, likely due to their prooxidant-mediated abiotic degradation and the novel nature of the conditioning film. Salinity, in conjunction with nutrient concentrations, emerged as a major driver of microbial abundance in the plastisphere. Though the putative pathogens, such as Vibrio spp. and total coliforms, were present at very low abundance in the aged plastisphere during the SW-Mon and PostM seasons, their persistence indicates their resilience even under nutrient-limited conditions. Although a closed microcosm system probably introduced bottle effects, influencing temporal changes in nutrient levels and microbial abundance, the study provides baseline insights into substrate- and season-driven patterns of plastisphere development. Overall, these findings underscore the dynamic interplay among various factors, including plastic types and seasonal environmental shifts, in shaping plastisphere maturation. This has potential implications for public health and ecosystem functioning in the natural marine environment. Employing functional metagenomics analysis in future in situ studies of plastisphere communities can provide further insights and is a way forward for predicting associated ecological risks.
Following the Viking experiments in 1976, many of the original inferences of biological metabolism have been replicated via abiotic mechanisms we now know are plausible on Mars' surface. While in many cases subsequent experiments have cast doubt on whether Viking truly detected life, numerous other studies since Viking have greatly expanded our knowledge of life's limits and microbial metabolism. In particular, increased characterization of Earth's subsurface has revealed the astounding complexity and adaptability of life, highlighting chemically based metabolisms as potentially strong targets for future life detection missions. Over the same time frame, we have gained knowledge of putatively more habitable regions in Mars' subsurface, relative to the original Viking lander surface sites, that could host similar organisms. In this review, we discuss the wealth of knowledge concerning the habitability of zones across Mars' surface/subsurface, and we suggest specific microbial metabolisms that should be targeted in future life detection missions based on laboratory and field studies under analogous conditions on Earth and with consideration of recommendations from the larger Astrobiology community. The ability to leverage these advancements in subsurface research toward the incorporation of increased specificity in future life detection efforts is additionally discussed in the context of current Mars subsurface mission progress and planetary protection and defense concerns.
The anaerobic ammonium oxidation (anammox) process, a low-carbon and energy-efficient biological nitrogen removal technology, is crucial for sustainable wastewater treatment and energy self-sufficiency. However, its performance stability is influenced by complex microbial interactions, and the gene-level mechanisms, particularly horizontal gene transfer (HGT), remain underexplored. This review comprehensively examines the interactions between anammox bacteria and their syntrophic partners, focusing on the functional genes involved in substrate degradation, electron transfer, cofactor biosynthesis, and quorum sensing (QS). These interactions form a network that supports wastewater treatment and system stability under external disturbances. Additionally, HGT mediated by bacteriophages, plasmids, transposons, and integrons reshapes anammox bacterial genomes, enhancing environmental adaptability, and promoting dynamic coexistence through competition and cross-feeding. This results in improved and stabilized nitrogen removal efficiency at the system level. A new paradigm is proposed, integrating multi-omics analysis with global bioinformatics and generative artificial intelligence to uncover the links between genetic activities and process performance. The review, by summarizing microbial interactions, functional genes, and HGT mechanisms in the anammox process under multi-omics analysis, is significance for improving system's nitrogen removal efficiency and system stability, and provides a theoretical basis for optimizing and regulating the process.
The efficient removal of refractory antibiotic contaminants such as ciprofloxacin (CIP) remains a critical challenge in biological water treatment. In this study, a sponge iron (SI)-microbe coupled system was constructed to enhance the degradation of CIP. The SI-microbe coupled system exhibited exceptional resilience compared to the control (CK). While the CK collapsed under high CIP loads (1-5 mg/L), with removal efficiency plummeting from 91% to 8%, the coupled system maintained stable performance (>93%). However, upon the withdrawal of SI, the system performance fluctuated drastically and deteriorated to near-zero removal by day 35. SI corrosion served as the cornerstone, providing a continuous supply of Fe(II) and abiotic H2O2. This established an in-situ self-sustaining Fenton-like cycle characterized by high steady-state H2O2 concentrations (5.2  mmol/L) and sustained ·OH production, preventing the oxidative failure observed in the CK. Furthermore, SI exerted directional selection pressure on the microbial community, shifting dominance towards specialized iron-cycling bacteria (Tessaracoccus, Zoogloea, Thermomonas, Arenimonas) and CIP-degrading genera (Saccharimonadales, Reyranella, Nakamurella). Quantitative quenching experiments revealed that microbial metabolism remained the dominant removal pathway (82.4%), far exceeding the abiotic Fenton‑like contribution (3.3%) and the microbial-induced Fenton‑like contribution (14.3%). Collectively, deep degradation of CIP was attained through a synergistic attack on its core structures including the piperazine ring, CF bond, cyclopropane ring, and carboxyl group. Overall, this study elucidates the synergistic chemo-biological mechanisms of the SI-microbe coupled system, providing a promising and enhanced biological treatment strategy for antibiotic-contaminated wastewater.
Anthranilic acid (ANTA) and its derivatives, such as N-methylanthranilic acid (NMAA) and 3-hydroxyanthranilic acid (3-HAA), are valuable aromatic chemicals with wide applications in the pharmaceutical and chemical industries due to their antibacterial, anti-inflammatory, and antioxidant properties. However, microbial production of these compounds remains limited by low titers and incomplete biosynthetic pathways. In this study, we constructed an efficient Escherichia coli platform for ANTA production through systematic metabolic engineering, including reduction of byproduct formation, enhancement of key enzyme expression, reinforcement of precursor supply, and optimization of amino donor availability. The engineered strain achieved 3.25 g/L ANTA in shake-flask cultures. Based on this platform, we further enabled the biosynthesis of NMAA and 3-HAA by screening and implementing efficient methyltransferases and hydroxylases. This resulted in the de novo production of 524 mg/L NMAA in shake flasks and 2.79 g/L 3-HAA in a 3-L bioreactor. This work establishes a versatile microbial chassis for ANTA production and provides a scalable platform for the biosynthesis of its high-value derivatives, offering new opportunities for sustainable biomanufacturing of aromatic compounds.
Carbapenem-resistant Enterobacterales (CRE) are increasing in the UK, but the drivers of this rise and effective treatment options remain uncertain. Ninety-seven acute NHS Trusts, including 192 UK hospitals, submitted data on 8,840 consecutive, non-duplicate CRE (October 2023-September 2024) and local laboratory methods. Predominant CRE species were Klebsiella pneumoniae (30.4%, 2,709/8,840), E. coli (29.3%, 2,592/8,840), Enterobacter cloacae complex (22.2%, 1,966/8,840). 21.8% (1,927/8,840) of CRE were collected in outpatient settings. Overall, 85.5% (7,279/8,513) of CRE underwent carbapenemase detection testing, with significant variation depending on species, specimen type and baseline antibiogram. Carbapenemases detected were OXA-48-like (22.3%, 1,967/8,840), NDM (18.6%, 1,645/8,840), KPC (9.2%, 817/8,840), IMP (2.0%, 178/8,840), VIM (0.7%, 62/8,840), multi-carbapenemase producers (4.0%, 351/8,840). 51.2% (4,526/8,840) of CRE were tested against ≥1 novel agent. In-house antimicrobial susceptibility testing availability was common for ceftazidime-avibactam (90.7%, 88/97) and cefiderocol (73.2%, 71/97), while less common for meropenem-vaborbactam (40.2%, 40/97), imipenem-relebactam (21.6%, 21/97), aztreonam-avibactam (11.3%, 11/97). OXA-48-like- (97.6%, 1,138/1,166) and KPC-producers (96.2%, 429/446) remained susceptible to ceftazidime-avibactam. KPC-producers to meropenem-vaborbactam (99.4%, 160/161) and imipenem-relebactam (98.4%, 62/63). Cefiderocol resistance was 32.4% overall and higher among NDM- (58.4%) and multi-carbapenemase-producers (50.3%). Ceftazidime-avibactam plus aztreonam synergy was performed for 17.2% (286/1,658) of aztreonam-resistant metallo-β-lactamase-producers; synergy was observed in 78.7% (225/286) of cases. Colistin resistance was 10.6% (153/1,445) among non-intrinsically resistant species. Whilst most UK CRE are tested for carbapenemases, coverage gaps persist. The community burden of CRE is increasing. Cefiderocol resistance is concerningly high, particularly among metallo-β-lactamase-producers.
Fecal indicator bacteria (FIB) have historically been used to assess public health risks associated with contact water recreation, and microbial source tracking (MST) has been introduced to distinguish human-associated fecal pollution from natural sources of animal feces. While MST can identify human-associated fecal pollution, without interpretation it cannot differentiate between small amounts of fresh fecal contamination and large amounts of decayed pollution, which can present vastly different health risks. This study examined the ratio of HF183 and pepper mild mottle virus (PMMoV) as an indicator of the age of fecal contamination. The correlation was also assessed between these two individual markers, the HF183:PMMoV ratio, and two enteric viruses, norovirus genogroup II (NoV GII) and human adenovirus (HAdV). A total of 364 samples were collected under varying weather conditions over two years at impacted and reference surface water sites in southern California, including estuaries and adjacent ocean locations. The mean concentrations of MST markers and enteric viruses were higher during the rainy season compared to the dry season, especially at the impacted sites. NoV GII showed seasonality with higher detections and concentrations during the rainy season, while HAdV did not show such seasonal trends. The HF183:PMMoV ratio demonstrated a stronger correlation with enteric viruses than either marker alone, but when seasonal and weather effects were factored out, the HF183:PMMoV ratio and PMMoV had a stronger relationship with the concentration of enteric viruses. The results of this study indicate that the HF183:PMMoV ratio is a more reliable indicator of human fecal pathogens than the two individual markers by themselves. SYNOPSIS: The HF183:PMMoV ratio is a reliable and robust indicator for recreational water quality.
Photoelectrotrophic denitrification (PEDeN) has emerged as a promising strategy for sustainable and high-efficiency nitrogen removal from wastewater by coupling solar energy with microbial denitrification. This review summarizes the development of PEDeN from conventional chemotrophic and electrotrophic denitrification, and synthesizes its system configurations, electron-transfer mechanisms, key influencing factors, and application potential. Current PEDeN systems can be classified into electrode-based and hybrid-based modes, which differ in device dependence, photosensitizer-denitrifier coupling, and practical application orientation. Recent advances in photosensitizer engineering, reactor design, and electron-transfer regulation have improved nitrogen removal and product selectivity, while expanding PEDeN applications to low C/N wastewater treatment, co-transformation of contaminants, and light-assisted nitrogen conversion in natural environments. However, practical implementation remains limited by material safety, light attenuation, system stability, and insufficient validation under real-wastewater conditions. Overall, this review provides a systematic framework for understanding PEDeN and highlights key directions for its future optimization and engineering application.
This study investigated the effect of applied voltage gradients on pollutant degradation and nitrogen removal in an electro-enhanced algal-bacterial symbiotic system treating marine aquaculture wastewater. Three groups with different voltage gradient conditions were set up in the experiment: E1 (1.8 V), E2 (2.2 V), and E3 (2.6 V). While all reactors achieved stable chemical oxygen demand (COD) removal (>70%), their total nitrogen (TN) removal efficiencies varied markedly. The system operating at 2.2 V achieved the best TN removal efficiency (77%), surpassing those at 1.8 V (68%) and 2.6 V (44%). The lower voltage limited anoxic denitrification, whereas the higher voltage suppressed ammonium assimilation and nitrification. Excessive voltage led to severe loss of microalgal biomass and a sharp decline in extracellular polysaccharide production, whereas insufficient voltage reduced extracellular polymeric substance secretion and biomass accumulation. Voltage gradients also shifted microbial community composition and enhanced deterministic processes during community assembly, with stochastic sub‑processes transitioning from "homogenizing dispersal" toward "drift". At voltages 2.2 V, broader ecological niches for both bacteria and microalgae supported a stable, highly functional denitrifying consortium dominated by unclassified_f__Rhodobacteraceae (24.90%) and Denitromonas (13.90%). Therefore, 2.2 V is identified as the optimal voltage for achieving high nitrogen removal and stable algal-bacterial symbiosis. These findings provide a mechanistic basis for optimizing mariculture wastewater treatment through voltage‑controlled engineering of algal‑bacterial symbiosis.
Coking wastewater (CW), characterized by high organic concentration, high toxicity, and poor biodegradability, poses significant challenges for biological treatment. The sulfate reduction-autotrophic denitrification-nitrification (SANI®) process, known for its robustness in treating municipal wastewater with high salinity and low sludge production, has not yet been explored for CW treatment under high-toxicity conditions. This study established a lab-scale continuous-flow SANI system treating real CW at stepwise increasing concentrations (30 %→60 %→100 % of real CW ratio) to investigate toxic pollutants removal performance and sulfur-mediated degradation mechanisms. The SANI process achieved efficient and stable removal of carbon (COD 83.5 %, TOC 93.3 %), nitrogen (NH4+-N 97.5 %, TN 85.1 %), and characteristic toxic pollutants (volatile phenols >99 %, SCN- >99 %) during 100 % CW treatment, with effluent biotoxicity substantially reduced. 16S rRNA gene sequencing revealed functionally complementary microbial consortia: sulfur-reducing genera (Gudongella, Desulfitobacterium) dominated the anaerobic reactor; mixotrophic denitrifiers (Thauera, Comamonas) enriched in the anoxic reactor; and nitrifiers (Nitrospira) coupled with sulfur-oxidizers (Thiobacillus) prevailed in the aerobic reactor. Metagenomic analysis elucidated complete nitrogen/sulfur metabolic networks and typical toxic pollutant degradation pathways: SCN- degradation proceeded via the CNO pathway, while phenol degradation followed the meta-cleavage pathway after hydroxylation. This study pioneers SANI process for sulfur-rich real CW treatment, demonstrating it enables simultaneous removal of carbon, nitrogen, and toxic pollutants-offering a breakthrough low-carbon alternative for industrial wastewater.
Soil organic matter (SOM) underpins fertility and carbon sequestration in black soils, yet the regulatory role of soil organic nitrogen (SON) in SOM stabilization remains poorly resolved. Herein, a total of 246 cropland black soils samples spanning three SOM gradients (10 g/kg interval) collected before spring plowing were analyzed using integrated multi-spectroscopic techniques and metagenomics to unravel chemical transformations and microbial mechanisms linking nitrogen and carbon processes. Results demonstrated that SOM accumulation drove a compositional transition from labile polysaccharides-C toward persistent alkyl-C, aromatic-C and aromatic-N containing structures. SON emerged as a dominant regulator of both SOM accumulation and stabilization by promoting aromatization and nitrogen incorporation, thereby enhancing aromaticity and structural persistence. Metagenomic evidences revealed intensified microbial coordination between soil organic carbon (SOC) and SON synthesis under high SOM conditions. On average, 64.8% microbial species encoded concurrent capacities for SOC and SON synthesis under favorable SOM enrichment status. 79.4% higher microbial network interaction and 83.3% stronger coupling intensity between SOC and SON synthesis were observed in favorable SOM enrichment status. Above improvements were attributed to coordinated upregulation of five SOC synthesis pathways and six SON synthesis pathways, with increases ranging from 21% to 57.5% and 24% to 99.8%, respectively. Overall, this study demonstrates that SON is not only a passive component but also an active driver that couples microbial carbon-nitrogen metabolism to govern SOM integrity, providing a novel biological perspective for understanding SOM integrity in black soils.
Dental prosthesis failure is often associated with biofilm-mediated infections, yet the combined roles of surface roughness and material chemistry remain underexplored. This observational, retrospective study investigated associations between these factors and biofilm density, pathogen selection, and prosthesis longevity. Surface roughness (Ra) and microbial colonization were analyzed for 85 explanted prostheses (fixed, removable, implant-supported, and orthodontic) and compared to control samples (polished enamel, sealants). Biofilm formation was quantified via optical density (OD) and colony-forming units (CFU/cm2), while pathogen profiles were identified using selective culture and biochemical assays. A strong positive correlation (R2 = 0.84, interpreted as a very strong correlation according to Evans' (1996) classification) was observed between surface roughness and biofilm accumulation. Smooth surfaces like zirconia (Ra ∼320 nm) exhibited low biofilm (OD 0.45), whereas rougher surfaces, particularly removable PMMA dentures (Ra ∼1100 nm), showed dense biofilms (OD up to 1.85) dominated by Candida spp. and Pseudomonas aeruginosa. Material chemistry was associated with distinct pathogen profiles: PMMA favored fungal and Gram-negative adhesion, while titanium promoted staphylococcal colonization. In this cohort, biofilm-associated infections were associated with reduced functional longevity; for example, implant crowns designed for 15+ years were removed after a mean of 5.4 years due to peri-implantitis. The study concludes that prosthetic failure is associated with the synergistic effect of surface topography, which correlates with biofilm quantity, and material composition, which is associated with distinct microbial ecology. These findings underscore the need for prostheses engineered with optimized surface smoothness and antimicrobial material chemistry. However, the observational, retrospective design limits causal inference; the culture-based methodology likely underestimates the full microbial diversity, particularly of anaerobic species; and the heterogeneity of device types limits direct comparability between groups.
Reducing cadmium (Cd) bioavailability is a sustainable approach to mitigating Cd exposure risks in contaminated agricultural soils. This study evaluated whether siderophore-producing bacteria (SPB) alleviate Cd stress in alfalfa (Medicago sativa L.) by regulating plant performance, soil properties, and rhizosphere microbial communities. A pot experiment was conducted under different soil Cd levels with or without SPB inoculation. Cadmium stress markedly inhibited alfalfa biomass production, iron uptake, and nitrogenase activity, while increasing soil ammonium accumulation and soil available Cd concentrations. In contrast, SPB inoculation significantly enhanced plant biomass and Fe accumulation, increased soil available phosphorus, and reduced ammonium accumulation as well as soil Cd bioavailability. Although SPB slightly decreased nodule number, it substantially increased nitrogenase activity and the predicted abundance of nitrogen fixation-related functional genes, suggesting that SPB may improve N-fixation-related activity without increasing nodule number under Cd stress. Microbial community analyses showed that SPB partially restored bacterial diversity and community structure disrupted by Cd contamination. Structural equation modeling further revealed that coordinated plant, soil, and microbial pathways jointly contributed to reductions in soil Cd bioavailability. Overall, these results demonstrate that SPB inoculation reduces Cd exposure risks and promotes Cd stabilization processes, representing a promising microbial strategy for improving ecological safety in Cd-contaminated agroecosystems.
Cholangiocarcinoma (CCA) is a heterogeneous group of malignant tumours originating along the biliary tract. Previous studies have demonstrated that CCA is characterised by altered gut microbial composition and disrupted bile acid metabolism, both of which are critical determinants of host metabolic homeostasis. Although bile reinfusion (BR) has been proposed to improve surgical outcomes in CCA patients, its systemic metabolic effects and interaction with gut microbiota remain poorly understood. Here, we employed faecal microbiota transplantation (FMT) from CCA patients, with or without BR, into Wistar rats to investigate host-microbiota metabolic interactions using integrated 1H NMR-based metabolomics and full-length 16S rRNA gene sequencing. Rats receiving CCA-derived microbiota displayed altered systemic metabolic phenotypes, characterised by lower levels of glucose, lactate, and succinate compared to normal microbiota recipients, whilst no significant differences in faecal metabolites were observed between these groups. Notably, BR was associated with shifts in gut microbial composition, marked by enrichment of Lactobacillaceae, altered intestinal fermentation metabolites (decreased short-chain fatty acids and increased succinate), and a convergence of peripheral plasma metabolite profiles towards those observed in healthy microbiota recipients. These findings reveal associations between bile reinfusion and shifts in microbial composition and systemic metabolic phenotypes, providing a basis for investigating microbiota-bile acid-host metabolic crosstalk and potential therapeutic implications for managing CCA-associated dysbiosis.
This study aimed to comprehensively assess oxidative stress responses and gut microbiota alterations in earthworms exposed to β-cypermethrin (β-CYP), and to analyze their relationship. β-CYP significantly increased malondialdehyde (MDA) content by up to 90.34% and peroxidase (POD) activity by up to 43.22% in a concentration-dependent manner (p < 0.05). Superoxide dismutase (SOD) activity was induced at 5mg/kg but inhibited at 40mg/kg. Although gut microbial alpha diversity showed no significant change, the composition and function were altered markedly. At the phylum level, Proteobacteria increased by 104.53%, while Actinobacteria and Firmicutes decreased by 46.30% and 61.38% at 5mg/kg, respectively, whereas fungal communities remained stable. KEGG analysis showed that microbial functions shifted from nutrient and energy acquisition toward detoxification and pollutant resistance. Correlation analysis showed significant associations between gut microbiota and host antioxidant capacity. These findings demonstrate that β-CYP exerts concentration-dependent toxicity via oxidative damage and gut microbial dysbiosis.