Search Results (3,212)

The flooded rice rhizosphere is a continuous reactive interface composed of sediment, porewater, root-surface oxic microdomains, and iron plaque, where redox processes and Fe cycling regulate Cd/As speciation, bioavailability, and plant accumulation. Engineered nanomaterials (ENMs) have shown potential for reducing Cd/As uptake in rice, but the coupled roles of microbial community responses, iron-plaque gating, and cross-interface elemental migration remain insufficiently integrated. This review synthesizes the current evidence on ENM transformation and partitioning at flooded rhizosphere microinterfaces, focusing on front-end speciation changes, root-surface retention, microbial functional regulation, and plant sequestration or transport. Correlative evidence suggests that rhizosphere microorganisms are associated with altered redox conditions, Fe cycling, As methylation potential, and metabolite secretion, which may influence Cd/As partitioning and cross-interface migration. However, direct causal validation of the complete ENM transformation–microbial response–Fe cycling–Cd/As flux–grain accumulation sequence within a single integrated system remains lacking. We further discuss how elevated CO₂, micro-/nanoplastics, Fe/DOM dynamics, and water management regimes may modify this framework, and we identify Sb as a theoretical boundary case because direct ENM–rice evidence remains limited. Finally, we highlight the need to integrate spatial tracing and imaging methods, including persistent luminescence tracing, LA-ICP-MS, NanoSIMS, and µ-XRF/µ-XANES, with metaomics to connect particle localization, microbial function, and contaminant fate. Full article

In resource-poor sandy habitats, alien plant co-invasion often triggers intense belowground competition mediated by rhizosphere microorganisms. However, the mechanisms by which these plants overcome nutrient limitations remain unclear. Here, we conducted an eight-month in situ monitoring of single- and co-invasion plots of Solanum rostratum and Cenchrus pauciflorus Benth. in the Horqin Sandy Land. By integrating soil enzyme assays with 16S rRNA and internal transcribed spacer (ITS) amplicon sequencing, we characterized their rhizosphere microbial community assembly. Co-invasion exposed both species to convergent biotic stress, characterized by the significant enrichment of the pathogenic fungi Didymella and Pseudogymnoascus (linear discriminant analysis (LDA) > 4.0). To mitigate these pressures, the dominant competitor, S. rostratum, specifically recruited a cross-kingdom phosphate-solubilizing consortium comprising Bacillus and Penicillium (LDA > 4.0). This targeted recruitment significantly enhanced rhizosphere activities, increasing phosphatase and sucrase to 86.10 U/g and 2.17 U/g, respectively, thereby maintaining available phosphorus at a high level (35.55 mg/kg). Conversely, the subordinate competitor, C. pauciflorus, lost key native stress-resistant bacteria such as Rubrobacter (relative abundance dropping from 5.39% to 3.27%) and failed to recruit effective microbes, leading to the rapid depletion of available phosphorus (dropping to 21.38 mg/kg). Ultimately, under dual nutrient and pathogenic stress, the precise recruitment and functional integration of cross-kingdom phosphate-solubilizing microbes are strongly linked to the divergent belowground competitive outcomes between these co-invading plants. Full article

Tailings remediation alleviates ecosystem degradation and protects species. To conserve terrestrial biodiversity and address sustainability challenges while achieving economic growth, numerous researchers have devoted efforts to monitoring ecological functions and optimizing community structures. This study investigates the microbial characteristics and functional diversity across ecological succession stages of tailings. Selecting three typical restoration stages, including biological crust, moss, and grassland stages, we adopt 16S rRNA and ITS gene amplification, Illumina high-throughput sequencing, spectroscopy, and network correlation analysis to explore the responses of soil multifunctionality index, microbial communities, and carbon metabolism during tailings restoration. The experimental results indicate that the functional diversity index increases with ecological succession and is significantly correlated with the bacterial genera Rubrobacter and Arenimicrobium, whereas no significant correlation is observed with dominant fungi. The network interactions among bacterial communities are gradually strengthened along the succession process. In terms of carbon metabolic functions, the relative abundances of galactose, starch, and sucrose metabolism pathways increase obviously with restoration progression, while inositol phosphate metabolism, peroxisome metabolism, retinol metabolism, glyoxylate and dicarboxylate metabolism, and xenobiotics metabolism exhibit no significant variations. These findings provide novel empirical evidence for explaining microbe-mediated ecological succession in tailing ecosystems and highlight the necessity of multi-perspective analysis for ecological restoration. Policy and practical implications emphasize that the application of specific microorganisms and their interspecific interactions to promote iron tailings ecological restoration should fully consider the spatiotemporal heterogeneity of tailings areas. This study deepens the understanding of differential microbial responses at different tailings restoration stages and provides actionable insights for balancing mining economic development and terrestrial ecosystem conservation. Full article

Mineral waters represent unique limnological ecosystems with stable physicochemical conditions and specialised microbial communities adapted to extreme environments. Bulgarian mineral waters remain comparatively underexplored despite their considerable ecological and biotechnological significance. These studies present a systematic narrative review of microbial diversity, ecological functions, and biotechnological potential of microbial communities from Bulgarian mineral springs. A total of 233 scientific sources published between 1990 and 2026 were analysed, of which 33 focused on Bulgarian sites. Data were retrieved from major scientific databases, regional reports and grey literature. Due to strong methodological heterogeneity, a qualitative synthesis was conducted, supported by bibliometric summaries of research focus and environmental context. The available evidence demonstrates that microbial communities in Bulgarian mineral waters include diverse bacteria, archaea, cyanobacteria, and microalgae that adapt to broad thermal and geochemical gradients. These microorganisms actively participate in element cycles, form complex biofilms, and show numerous physiological adaptations to oligotrophic and extreme temperature conditions. Bulgarian systems broadly reflect global microbial patterns but exhibit additional variability linked to contrasting hydrogeological settings. Many taxa produce thermostable enzymes, antimicrobial compounds, and exopolysaccharides with significant biotechnological potential. The review identifies significant research gaps and emphasises the importance of integrated multi-omics approaches for future exploration of Bulgarian mineral water ecosystems. Full article

Microbially induced corrosion is a common problem in the petroleum industry. In this study, weight loss and surface analysis of grade 20 carbon steel corrosion witness samples were used to evaluate biocorrosion in produced fluids from different wells (Romashkino oilfield, Republic of Tatarstan, Russia). The structure of the resulting microbial communities in the systems with high corrosion indicators was elucidated. The addition of acetate/lactate, yeast extract, and sulfate was found to promote the growth of individual microorganisms in the designed systems and to increase the corrosion rate in several samples (to an average of 0.12 mm year⁻¹). The results of 16S rRNA gene sequence analysis showed that water from different wells from the Romashkino oilfield had distinct microbial compositions. The main genera in the analyzed waters were Oleidesulfovibrio, Halanaerobium, Proteiniphilum, Acetobacterium, Fusibacter, and Methanocrinis, but their relative abundances depended on the water itself and the type of stimulation. Acetogenic bacteria of the genera Fusibacter, Proteiniphilum, Acetobacterium, and acetoclastic methanogenic archaea Methanocrinis became dominant in the microbial community structure in the acetate-enriched systems in water from one of the studied wells. Electron donors, generated by various bacteria and artificially introduced ones, facilitated active dissimilatory sulfate reduction by Oleidesulfovibrio, Desulfotignum, Desulfocurvus, and Pseudodesulfovibrio in water from another production well. The obtained results are important for identifying the causes of premature failures of oilfield equipment, particularly in areas where microbial enhanced oil recovery is used. Full article

The treatment of high-salinity, low-carbon marine aquaculture wastewater poses significant challenges for biological denitrification. This study systematically evaluated the performance of a polycaprolactone (PCL)-based aerobic denitrification biofilter under varying temperatures (15 °C and 25 °C) and PCL addition levels (282, 564, 846, 1128, and 1410 g). Optimal nitrogen removal, total nitrogen (TN) removal efficiency exceeding 92%, was achieved with 1128 g PCL at 15 °C (HRT 10 h) and 1410 g PCL at 25 °C (HRT 8 h), significantly outperforming the low-PCL baseline treatment. Microbial community analysis revealed that increased PCL dosage promoted the dominance of the hydrolytic genus Flavobacterium over Simplicispira, enhancing polymer degradation capacity and system stability. Metagenomic sequencing further elucidated the complete PCL degradation pathway, wherein hydrolysis products were oxidized to generate NADH and FADH₂, serving as electron donors for denitrification. Key functional genes (narG, nirK, nosZ) and enzymes associated with both PCL decomposition and nitrate reduction were significantly enriched in high-performance reactors (e.g., AT15H6, AT25H6, ET15H10, ET25H10), correlating strongly with observed nitrogen removal rates. By integrating reactor performance with microbial ecology and functional genetics, this work provides a comprehensive “material–microorganism–gene–performance” framework, offering both practical strategies and mechanistic insights for enhancing denitrification in saline aquaculture systems. Full article

Ornamental fountains in the Alhambra and Generalife (Granada, Spain) constitute complex socio-ecological systems where water, stone, and biological communities interact, making them highly vulnerable to biodeterioration caused by phototrophic microorganisms such as cyanobacteria, green algae, and diatoms. Conventional chemical biocides, although widely applied, present significant drawbacks including toxicity, material degradation, ecological imbalance, and limited long-term effectiveness. In this context, this study evaluated the potential of algicidal bacteria as a sustainable alternative for controlling phototrophic growth in heritage environments. Water samples from eight ornamental fountains were analyzed using 16S ribosomal RNA (16S rRNA) gene sequencing to characterize bacterial communities and identify taxa previously reported with algicidal activity. Statistical analyses were conducted to assess relationships between microbial community structure and biofilm development. In parallel, functional screening assays using filtered fountain waters against Chlorella vulgaris were performed to evaluate intrinsic inhibitory capacity. The most active sample was selected for bacterial isolation and further validation through co-culture assays, cell density measurements, and pulse-amplitude-modulated (PAM) fluorometry. A total of 18 genera with reported algicidal capacity were detected, representing a substantial fraction of the microbiome across all samples. However, no significant association was found between these taxonomic metrics and biofilm development, highlighting a decoupling between taxonomic composition and functional activity. The most active isolate, identified as Stenotrophomonas maltophilia strain LIG25, caused a rapid decline in photosynthetic efficiency and achieved more than 98% inhibition of algal growth. These findings demonstrate that ornamental fountain microbiomes represent a reservoir of native biocontrol agents and support the development of eco-friendly strategies for cultural heritage conservation. Full article

The accumulation of intermediate products, particularly volatile fatty acids (VFAs) like propionic acid (HPr) or its dissociated form, can inhibit biogas production during anaerobic digestion (AD) at low concentrations. Knowledge about the response of microorganisms to VFA inhibition can help control the digesters. In this study, we aimed to determine how sodium propionate (NaPr) inhibits the AD of municipal sewage sludge by identifying shifts in the microbial community. Four 5 L reactors were operated in semi-continuous mode using sewage sludge and then loaded with different levels of NaPr. The reactors operated at 37 °C with two hydraulic retention times. The results show that there was no apparent inhibition of biogas production at NaPr loading up to 20.3 mmol·L⁻¹. However, moderate inhibition was observed at 81 mmol·L⁻¹, corresponding to an approximate 10% decrease in methane production, while a ≈40% decrease in methane production was observed at 135.3 mmol·L⁻¹. Sequencing analysis revealed that the community composition was dominated by Bacillota, Bacteroidota, Proteobacteria, Chloroflexi, and Cloacimonadota, with Halobacterota and Euryarchaeota as the main archaeal groups. PERMANOVA revealed incubation time as the primary driver of community structure, followed by NaPr concentration. Elevated NaPr levels resulted in a decline in Methanothrix and Methanobrevibacter and promoted distinct syntrophic propionate-oxidizing bacteria (SPOB). Full article

The increasing worldwide demand for sustainable energy and effective waste management has heightened interest in solutions. Microbial fuel cells (MFCs) represent a potential category of bioelectrochemical systems that directly transform the chemical energy contained in organic waste into electrical energy via the metabolic processes of electroactive microorganisms. In the last twenty years, significant advancements have occurred in the comprehension of extracellular electron transfer (EET) mechanisms, biofilm formation, microbial community dynamics, electrode material engineering, and reactor design, resulting in marked enhancements in power density and wastewater treatment efficacy. Despite these breakthroughs, the extensive deployment and commercialization of MFC technology are constrained by various hurdles, including inadequate energy recovery, elevated material and fabrication expenses, operational instability, and the intricacies of system scale-up. This cutting-edge analysis offers a thorough evaluation of recent advancements in MFCs and their incorporation with sophisticated technology for waste management and energy generation. Focus is directed towards essential bioelectrochemical principles, microbial and biofilm engineering techniques, sophisticated electrode and membrane materials, reactor designs, and hybrid MFC systems integrated with anaerobic digestion, microbial electrolysis, and advanced oxidation methods. Ultimately, emerging trends, significant knowledge deficiencies, and future research goals are defined to inform the advancement of next-generation MFC systems that support circular economy and net-zero energy initiatives. Full article

Microplastic pollution is a problem of global concern, but its effects on forest soils are largely overlooked. This study is based on a laboratory experiment where the effects of soil-added polyethylene microplastic particles (MP-) of two sizes (60 μm and 140 μm) (Cospheric LLC, USA) were measured to examine their effects on three types of temperate forest: dry pine forest, beech-dominated forest, and ash-dominated riparian forest that differ greatly in several physicochemical and biological soil properties. The addition of MP- did not significantly alter the respiration rate of any of the forest soils studied (p = 0.6303), as shown by ANOVA. Soil microbial biomass, as measured by the phospholipid fatty acid (PLFA) method, decreased under 60 µm MP treatment but not under 140 µm MP treatment (p = 0.0094). MP- did affect microbial community structure, especially increasing the proportion of bacteria in the community under 60 µm MP treatment (p = 0.0023). MP- affected the PLFA pattern, as shown by PERMANOVA analysis along with NMDS ordination; the effect was similar in the three studied forest types. As shown by SIMPER analysis, there was a relative decrease in fatty acid 16:1ω7 and a simultaneous increase in 16:0 and 18:0 under both MP treatments. This may potentially serve as an indication of MP pollution in temperate forest soils. Our results suggest that forest soil bacteria, as a group, may benefit from MPs at the expense of fungi, which provides a new perspective on how soil microorganisms interact under globally common MP pollution. Full article

Desert reclamation into oases promotes soil organic carbon (SOC) accumulation across soil profiles, with nitrogen (N) fertilization being a key driver. However, the possible role of soil microorganisms in coupled C–N processes remains poorly understood in desert regions. We conducted a soil incubation experiment to evaluate the effects of N addition to varied soil layers on soil properties, CO₂ efflux, and microbial communities. The fertilized treatments (N, NP, and NPK) were compared with the unfertilized control (CK). All treatments were derived from the original desert soil. After incubation, SOC content decreased by 8–28% below the topsoil (20–100 cm) in the CK treatment, while it increased by 6–32% throughout the soil profile (0–100 cm) in all fertilizer treatments. Compared to the CK, all fertilizer treatments reduced daily and cumulative CO₂ emissions throughout the soil profile, with NP and NPK treatments showing greater reductions (3–19%). Fertilizer addition consistently enriched the phylum Firmicutes—notably the genera Virgibacillus and Bacillus—while lowering the relative abundance of other major phyla. After incubation, all treatments reduced microbial diversity and richness, with the most pronounced declines observed under fertilization. These community shifts were closely linked to changes in SOC and total N below the topsoil. These findings demonstrate that N-based fertilization promotes SOC accumulation in desert regions through microbial community restructuring. This study highlights the important role of exogenous nutrients, particularly N, in regulating C–N cycling and organic C sequestration in deep soil during desert oasis transformation. Full article

Both the gut and the lungs possess a microbiome, a community of commensal bacteria, archaea, fungi, and viruses that perform important housekeeping functions in those organs. The colonic microbiome primarily ferments indigestible dietary fibers into essential short-chain fatty acids, synthesizes essential vitamins, regulates the mucosal immune system, and forms a protective barrier against pathogenic colonization. The lung microbiome maintains respiratory health primarily by regulating mucosal immunity, providing a physical barrier against invading pathogens, and producing beneficial metabolites. Several colonic microbiota metabolites, including the short-chain fatty acids acetate, propionate, and butyrate, together with the tryptophan metabolites indole-3-acetate and indole-3-propionate, secondary bile acids, and the polyamines spermidine and putrescine, are transported to the lungs via the gut–lung axis. These colonic microbiota biomolecules suppress lung inflammation, strengthen immune homeostasis, and reduce the severity of respiratory diseases. In contrast, lung microorganisms and their metabolites can travel to the gut via the gut–lung axis, influencing intestinal immune responses and potentially leading to an imbalance of gut microorganisms or dysbiosis. This means that respiratory diseases may lead to digestive issues, intestinal inflammation and chronic diseases. Here, we have reviewed this crosstalk and its impact on the principal pulmonary diseases: asthma, chronic obstructive pulmonary disease, cystic fibrosis, bronchogenic carcinoma, COVID-19, interstitial lung diseases, pneumonia, and tuberculosis. It is concluded that the gut microbiome plays a significant part in lung health and disease. Diet, tobacco smoking and electronic cigarette vaping all impact both the gut and lung microbiomes. Full article

This study investigated the effects of Lactiplantibacillus plantarum SJ-4 inoculation, partial replacement of sodium chloride (NaCl) with potassium chloride (KCl) and calcium ascorbate (CaA), and their combined treatment on the fermentation quality of fermented pork sour meat. Microbial community and metabolomic analyses were further integrated to explore the potential mechanisms related to flavor formation and quality changes. The combined treatment (LP + K-Ca group) improved the flavor profile, increased the contents of volatile compounds and free amino acids, reduced several undesirable flavor-related compounds, and contributed to better fermentation quality. Compared with the control group (C), total free amino acids and essential amino acids in the LP + K-Ca group increased by 4.95% and 22.71%, respectively, while the contents of undesirable compounds such as 2-nonenal, hypoxanthine, and ketones decreased by 73.65%, 73.40%, and 9.58%, respectively. Key flavor-related microorganisms included Macrococcus, Staphylococcus, and Lactiplantibacillus. These microorganisms are intricately linked to metabolic products such as amino acids, fatty acids, and organic acids, which may provide important precursors for volatile flavor formation. Overall, the combined treatment of 40% NaCl replacement with 24% KCl and 16% CaA, together with 2% L. plantarum SJ-4 inoculation, showed potential for improving flavor formation and fermentation quality in salt-reduced sour meat based on partial NaCl replacement. Full article

Orchard soils have distinct stratification heterogeneity, while the responses of soil organic carbon mineralization (essentially microbial-mediated decomposition of organic matter, mainly producing CO₂) and bacterial communities to exogenous carbon addition in different soil layers are still unclear. In this study, a laboratory incubation experiment was conducted to investigate the differences in soil organic carbon mineralization characteristics and bacterial communities between glucose addition and no-glucose addition treatments in three soil layers (N1: 0–20 cm, N2: 20–40 cm, N3: 40–60 cm) of hilly orchards. The results demonstrated that soil organic carbon mineralization rates in all layers generally declined with increasing incubation duration. At D3, compared with the CK group, glucose addition increased the soil organic carbon mineralization rate by 3.28-fold, 9.30-fold, and 15.03-fold in the N1, N2 and N3 soil layers, respectively. Cumulative organic carbon mineralization followed the order N1 > N2 > N3. Compared with the CK treatment, glucose addition increased C₀ by 65.62% and 203.97% in the N2 and N3 soil layers, respectively. Two-way ANOVA was applied to quantitatively separate and compare the contributions of carbon addition treatment, incubation time and soil layer, and Beta diversity analysis revealed that soil layer was the primary driving factor. Under glucose addition, the key microorganisms related to organic carbon mineralization varied across soil layers: Gemmatimonadota and Acidobacteriota may exert a negative effect on soil organic carbon mineralization in orchard soils, whereas copiotrophic taxa, including Sphingomonas and Bacteroidota, contributed more strongly to carbon mineralization. Our results highlight the pronounced impact of labile carbon input on soil organic carbon mineralization within different soil layers, and reveal associations between soil bacterial communities and organic carbon mineralization in orchard ecosystems. Full article

Global salinization affects approximately one billion hectares of land in more than 100 countries, posing a severe threat to food security and ecosystem sustainability. Microbial remediation using plant growth-promoting microorganisms offers an eco-friendly alternative to physicochemical methods. However, bridging the gap between laboratory cultivation of single strains and field-scale application of synthetic microbial communities (SynComs) remains difficult, owing to inconsistent efficacy and a lack of unified design frameworks. This review examines the evolution from single strains to rationally designed SynComs for saline soil remediation. A ‘structure–function–mechanism’ framework is proposed, integrating five core microbial modules, namely ion regulation and osmotic stabilization, ethylene and phytohormone modulation, antioxidant activation, nutrient cycle activation, and systemic resistance induction. The review elucidates key determinants of synthetic community success, including functional complementarity, strain compatibility, and host–environment matching, while revealing a marked quantitative gap between controlled experiments and field performance. Key bottlenecks are identified, including the lack of high-throughput compatibility screening, poorly quantified long-term ecological risks, and the absence of standardized application guidelines across agro-ecological zones. Finally, emerging avenues are discussed, such as microbial–microalgal symbiosis and AI-assisted design, outlining a roadmap for next-generation smart microbial products integrated into climate-resilient farming systems. Full article