Inflammatory bowel disease (IBD) is a chronic intestinal disorder with recurrent inflammation for which effective therapeutic options remain limited. Probiotics from the Bifidobacterium genus have potential beneficial effects on the prevention of IBD by improving intestinal barrier integrity and modulating immune responses. However, whether these effects are mediated by the regulation of gut metabolism remains largely unclear. This study was designed to explore the protective effect of an infant-derived Bifidobacterium animalis subsp. lactis 832 (B. lactis 832) on dextran sulfate sodium (DSS)-induced colitis in mice and its underlying mechanism. B. lactis 832 treatment significantly alleviated colitis severity (p < 0.05), as evidenced by reduced weight loss, disease activity index (DAI), and colonic injury, accompanied by significantly decreased pro-inflammatory cytokine expression and increased Il10 expression (p < 0.05). It also improved intestinal barrier integrity and modulated gut microbiota composition by reducing potentially pathogenic bacteria while enriching beneficial taxa. Surprisingly, metabolomic analysis revealed that B. lactis 832 intervention enhanced intestinal phospholipid metabolism, particularly increasing phosphatidylethanolamine (PE) and phosphatidylcholine (PC) levels. Notably, PE or PC supplementation recapitulated the protective effects against DSS-induced colitis (p < 0.05). These findings suggest that B. lactis 832 alleviates colitis through microbiota-associated metabolic regulation, highlighting a key role for phospholipid metabolism in mediating probiotic effects.

Environmental factors are widely assumed to influence nitrogen (N) cycle processes in lakeside wetlands. However, recent studies suggested that shifts in environmental conditions do not consistently correspond to proportional changes in N-functional potential. To elucidate the contributions of different drivers, multiple influences, including environmental factors, microbial diversity, functional microbial genera, and gene abundance, were examined by integrating a random forest model (RFM), variation partitioning analysis (VPA), network co-occurrence analysis, and structural equation modeling (SEM). Almost 66 % of functional genes in RFM analysis exhibited a preferable R2 fit over 0.6. VPA analysis revealed that functional microbial genes (55.1 %) and genera (35.1 %) accounted for over 90 % of the explanatory contribution rate, surpassing environmental influences (4.3 %) and diversity indices (5.4 %). Network co-occurrence demonstrated that denitrification genes (norB/C/D/E; napA) formed central connective nodes in the network linked to nitrogen-cycle functional potential, and functional genera-gene linkages were closely aligned with variations in N-functional potential. SEM results further revealed that environmental factors did not exhibit a significant direct association with functional genes; instead, their effects were mediated indirectly through the restructuring of microbial community composition. Under long-term hydrological and nutrient fluctuations, microbial communities exhibited internal co-occurrence networks that were associated with N-cycle functional potential. Recognizing these internally structured microbial associations provides new insight into microbial contributions to N-cycle functional potential and may guide the design strategies of sustainable lakeside wetland restoration.

Pressure-retarded osmosis (PRO) is a promising technology for osmotic energy harvesting and storage, particularly when using hypersaline draw solutions that promoted enhanced power generation. However, the osmotic membranes for PRO must be operated under high pressures (>50 bar) to realized full energy potential of the hypersaline solution. Conventional osmotic membranes with highly porous and thin substrates to enhance mass transfer usually have low mechanical stabilities and suffer severe deformation under such critical operating conditions. To overcome the trade-off between mechanical strength and mass transfer in conventional osmotic membranes, this study strategically engineered the membrane substrate with large finger-like pores to enhance mass transfer, while reinforcing mechanical strength through innovative membrane material selection and modification. Specifically, aluminium tri-sec-butoxide (ASB), a robust metal oxide, was used as membrane pore former and filler to first form a highly porous mix-matrix polyetherimide (PEI) substrate. Subsequently, 3-aminopropyl trimethoxysilane (APTMS)-based sol-gel crosslinking was conducted to form inorganic interconnected networks within the polymeric membrane matrix, which substantially improved membrane strength without compromising mass transfer properties. The optimized membrane possessed high mass transfer coefficient of 2.47 x 10(-6) m/s and enhanced mechanical properties, and it demonstrated stable operation under operating pressure up to 55 bar and achieved power density of around 25 W/m(2), with a peak power density of similar to 30 W/m(2) attained at an optimal operating pressure of similar to 35 bar using a 2 M NaCl draw solution. Such peak performance was maintained for over 15 h at elevated pressure, within only 5% decline in power density was observed. This study highlights the importance of combining pore structure tailoring with chemical crosslinking to overcome the property trade-offs for high-pressure PRO membranes, providing fundamental insights and a promising basis for further studies toward sustainable osmotic energy harvesting and storage.

Lakeside wetlands play a critical role in mitigating non-point source nitrogen (N) pollution, yet the mechanisms underlying vertical microbial stratification across the water-sediment interface remain unclear. Based on a single dry-season sampling campaign conducted in February 2023, microbial communities and N-cycling functional genera exhibited a clear depth-dependent stratification under hydrological fluctuation, but their responses were not vertically synchronized. The sediment profile functioned as a three-tier system, shifting from disturbance-buffered surface processes to subsurface-dominated regulation: weak soil-microbe coupling in surface layers (0-10 cm), coupling between soil and microbial indicators strengthened at intermediate depths (10-40 cm), and soil-mediated control became more evident in the lower-profile layer (40-50 cm). Environmental effects emerged at 20-30 cm, whereas microbial network connectivity peaked at 30-40 cm, suggesting a delayed and partially dissociated relationship. Denitrifying taxa showed a weak V-shaped depth distribution, with the highest relative abundance in the top 5 cm (32.5% ± 17.0%) and a minimum at 10-20 cm (23.8% ± 14.1%). Soil parameters explained most of the community variation, while vegetation and hydrological factors contributed less. These findings identified the intermediate layer (10-40 cm) as a critical functional zone for N transformation, while the lower-profile layer (40-50 cm) may retain residual denitrification-related potential under resource-limited conditions. These findings suggested that subsurface soil-microbe interactions should be considered when evaluating dry-season N-cycling potential in the lakeside wetlands, although their temporal stability and actual functional activity require further verification.

The landscape configuration of lakeside wetlands plays a pivotal role in mediating water purification, making it essential to investigate how ecological restoration in the wetlands around lakeshore reshapes these patterns to improve water quality. In this study, the effectiveness of a restored plateau lakeside wetland in water purification capacity was evaluated by analyzing the geographical variation of contaminant concentrations from inlets to outlets and identifying potential key landscape factors affecting purification capacity. The results showed that the average removal efficiencies of total nitrogen, total phosphorus, and permanganate index were 63.76 %, 71.10 %, and 28.74 %, respectively, demonstrating the significant capability of the restored lakeside wetland in nutrient removal and water purification. Redundancy analysis and variation partitioning analysis indicated that interface properties had the greatest impact on purification capacity (28.1 %), followed by the synergistic effect of structural parameters and habitat elements for land use (16.3 %), and the independent effect of habitat elements for land use (13.2 %) and structural parameters (12.2 %). Among them, gentle slopes were found to significantly enhance nitrogen retention (p < 0.05). The vegetated interface areas with complex community structures significantly enhanced nutrient removal, justifying the strategic construction of grassland-water and forest-water interfaces in lakeside wetlands to maximize contaminant mitigation. These findings established actionable frameworks for optimizing lakeside wetland restoration through targeted landscape configuration and management, thereby significantly enhancing long-term water quality protection in lake ecosystems.

Although remote sensing has become a common tool for monitoring mountainous reservoirs, studies on the detection of phytoplankton community compositions (PCCs) remain insufficient. Based on satellite and field data, we developed a mathematical model incorporating fuzzy logic and probabilistic methods to directly estimate the biomass of seven different phytoplankton species in Huating Lake. Water surface temperature (WST) and chlorophyll-a concentration ([Chl-a]) were selected as input parameters for this model. The WST data were processed using a single-channel algorithm that combined the brightness temperature conversion model and land surface emissivity algorithm. Inversion of [Chl-a] was conducted using an empirical approach to compare the four models developed for the two sensitive reflectance bands. The [Chl-a] values obtained from these models were significantly correlated with the field data (R > 0.8). The optimal model was selected based on validation results. After obtaining the inversion results for the WST and [Chl-a], we applied a fuzzy probabilistic model to determine the PCCs in Huating Lake from 2013 to 2023. A comparison with the measured data confirmed that this method reliably estimated PCC biomass (R > 0.65). However, the modeling accuracy was not particularly high for Bacillariophyta and Euglenophyta with high biomass. We analyzed the spatial and temporal distribution of PCCs in Huating Lake over 10 years from 2013 to 2023 and found that the results were reasonable. The results demonstrate that the fuzzy probabilistic approach offers a novel methodology for estimating the biomass of seven phytoplankton species. This method facilitates the expansion of remote-sensing technology for monitoring PCC changes in mountainous reservoirs and provides scientific data support for understanding algal bloom mechanisms and developing prevention strategies.

The linkages of distributed ponds are utilized in conjunction with one another to remediate non-point source (NPS) pollution in a water-scarce basin. This study provides an overview of a state-of-the-art thorough evaluation of ponds, which offers insight into the majority of topics covered by the ongoing scientific studies, including their various functions and factors affecting their functioning on the hydrological, physicochemical, and biological processes, such as environmental climate factors and basin-specific landscape configuration parameters, as well as process parameters for design, operation and management aspects. The linkages of ponds provide a variety of sustainable services (6R functions), such as resources, restoration, reduction, reuse, recycling, and recovery. The significance of regional environmental geochemical substrates in the ponds, such as red soil, as a hotspot for microbial reaction is emphasized to demonstrate the significant contribution of the migration and transformation of Fe/N cycles to the pollution removal process. In this review, 178 original research publications were thoroughly analyzed to improve our knowledge of the iron-nitrogen cycle in wetlands. From a molecular biology standpoint, the identification of functional microbe species and genes linked to microbially driven iron-nitrogen cycle activities is delved. Reliable data and homogeneous datasets from 42 studies were collected. The correlation analysis results demonstrated Feammox rates contributed to the N loss amount (r = 0.871; p < 0.01), and they had a positive correlation with Fe(III) concentration (r = 0.965; p < 0.01). The proposal for the treatment of NPS pollution by large-scale linkages of ponds in a basin involves optimizing Fe/N microbial processes to promote iron crystallization and efficient circulation of Fe(II) and Fe(III). The co-benefits of geochemistry, biotechnology, and environmental science should be considered when managing contamination in engineering applications. The linkages framework for integrated ponds, which incorporates macro (watershed management) and micro (biogeochemical cycle mechanism) investigations, provides a systematic approach to the application of integrated ponds and sustainable water management for NPS pollution control.

Osmotic battery (OB), alternating the operation of reverse osmosis (RO) for charging and pressure-retarded osmosis (PRO) for discharging, is an emerging grid-scale energy storage system (ESS) that offers complementary advantages over other existing grid ESSs. OB utilizes osmotic pressure difference of two solutions as a media for energy storage. However, OB faces the issue of energetic-kinetic trade-off generally applicable in all the ESSs. This study aims to quantitatively analyze this trade-off in OB and to develop effective strategies to address this issue. Our analyses suggest that this trade-off can be addressed by (1) raising the initial high-salinity solution concentration (c(HS,0)), and (2) using more water permeable osmotic membranes with a suitable high-salinity solution. For example, increasing the c HS , 0 from 1.2 M to 2.4 M increases energy density from 0.5 to >1.0 kWh & sdot;m(-3) along with an enhanced power density and a stable high roundtrip efficiency (RTE) above 66 %, albeit requiring membranes with substantially improved mechanical strength. Furthermore, using high-permeance nanofiltration-type osmotic membranes with divalent high-salinity solution could improve the peak power density to above 50 W & sdot;m(- 2) while maintaining energetic performance. This study not only offers effective strategies to ease the energetic-kinetic trade-off but also recommends important directions for developing future osmotic membranes for OB.

Vibrio cholerae causes cholera, an important cause of death worldwide. A fuller understanding of how virulence is regulated offers the potential for developing virulence inhibitors, regarded as efficient therapeutic alternatives for cholera treatment. Here we show using competitive infections of wild-type and mutant bacteria that the regulator of chitosan utilization, ChsR, increases V. cholerae virulence in vivo. Mechanistically, RNA sequencing, chromatin immunoprecipitation with sequencing and molecular biology approaches revealed that ChsR directly upregulated the expression of the virulence regulator, TcpP, which promoted expression of the cholera toxin and the toxin co-regulated pilus, in response to low O2 levels in the small intestine. We also found that chitosan degradation products inhibit the ChsR-tcpP promoter interaction. Consistently, administration of chitosan oligosaccharide, particularly when delivered via sodium alginate microsphere carriers, reduced V. cholerae intestinal colonization and disease severity in mice by blocking the chsR-mediated pathway. These data reveal the potential of chitosan oligosaccharide as supplemental therapy for cholera treatment and prevention.

Mitochondrial dynamics are critical in cellular energy production, metabolism, apoptosis, and immune responses. Pathogenic bacteria have evolved sophisticated mechanisms to manipulate host cells' mitochondrial functions, facilitating their proliferation and dissemination. Salmonella enterica serovar Typhimurium (S. Tm), an intracellular foodborne pathogen, causes diarrhea and exploits host macrophages for survival and replication. However, S. Tm-associated mitochondrial dynamics during macrophage infection remain poorly understood. In this study, we showed that within macrophages, S. Tm remodeled mitochondrial fragmentation to facilitate intracellular proliferation mediated by Salmonella invasion protein A (SipA), a type III secretion system effector encoded by Salmonella pathogenicity island 1. SipA directly targeted mitochondria via its N-terminal mitochondrial targeting sequence, preventing excessive fragmentation and the associated increase in mitochondrial reactive oxygen species, loss of mitochondrial membrane potential, and release of mitochondrial DNA and cytochrome c into the cytosol. Macrophage replication assays and animal experiments showed that mitochondria and SipA interact to facilitate intracellular replication and pathogenicity of S. Tm. Furthermore, we showed that SipA delayed mitochondrial fragmentation by indirectly inhibiting the recruitment of cytosolic dynamin-related protein 1, which mediates mitochondrial fragmentation. This study revealed a novel mechanism through which S. Tm manipulates host mitochondrial dynamics, providing insights into the molecular interplay that facilitates S. Tm adaptation within host macrophages.

In recent years, the arctic tundra has been subject to more frequent stochastic biotic or extreme weather events (causing plant dieback) and warmer summer air temperatures. However, the combined effects of these perturbations on the tundra ecosystem remain uninvestigated. We experimentally simulated plant dieback by cutting vegetation and increased summer air temperatures (ca. +2°C) by using open-top chambers (OTCs) in an arctic heath tundra, West Greenland. We quantified surface greenhouse gas fluxes, measured soil gross N transformation rates, and investigated all ecosystem compartments (plants, soils, microbial biomass) to utilize or retain nitrogen (N) upon application of stable N-15 isotope tracer. Measurements from three growing seasons showed an immediate increase in surface CH4 and N2O uptake after the plant dieback. With time, surface N2O fluxes alternated between emission and uptake, and rates in both directions were occasionally affected, which was primarily driven by soil temperatures and soil moisture conditions. Four years after plant dieback, deciduous shrubs recovered their biomass but retained significantly lower amounts of 15N, suggesting the reduced capacity of deciduous shrubs to utilize and retain N. Among four plant functional groups, summer warming only increased the biomass of deciduous shrubs and their 15N retention, while following plant dieback deciduous shrubs showed no response to warming. This suggests that deciduous shrubs may not always benefit from climate warming over other functional groups when considering plant dieback events. Soil gross N mineralization (~ -50%) and nitrification rates (~ -70%) significantly decreased under both ambient and warmed conditions, while only under warmed conditions immobilization of NO3 - significantly increased (~ +1900%). This explains that plant dieback enhanced N retention in microbial biomass and thus bulk soils under warmed conditions. This study underscores the need to consider plant dieback events alongside summer warming to better predict future ecosystem-climate feedback.

Adherent-invasive Escherichia coli (AIEC) strain LF82, isolated from patients with Crohn's disease, invades gut epithelial cells, and replicates in macrophages contributing to chronic inflammation. In this study, we found that RstAB contributing to the colonization of LF82 in a mouse model of chronic colitis by promoting bacterial replication in macrophages. By comparing the transcriptomes of rstAB mutant- and wild-type when infected macrophages, 83 significant differentially expressed genes in LF82 were identified. And we identified two possible RstA target genes (csgD and asr) among the differentially expressed genes. The electrophoretic mobility shift assay and quantitative real-time PCR confirmed that RstA binds to the promoters of csgD and asr and activates their expression. csgD deletion attenuated LF82 intracellular biofilm formation, and asr deletion reduced acid tolerance compared with the wild-type. Acidic pH was shown by quantitative real-time PCR to be the signal sensed by RstAB to activate the expression of csgD and asr. We uncovered a signal transduction pathway whereby LF82, in response to the acidic environment within macrophages, activates transcription of the csgD to promote biofilm formation, and activates transcription of the asr to promote acid tolerance, promoting its replication within macrophages and colonization of the intestine. This finding deepens our understanding of the LF82 replication regulation mechanism in macrophages and offers new perspectives for further studies on AIEC virulence mechanisms.

Dissolved organic matter (DOM) constitutes the most active fraction in global carbon pools, with estuarine sediments serving as significant repositories, where DOM is susceptible to dynamic transformations. Anthropogenic nitrogen (N) and sulfur (S) inputs further complicate DOM by creating N-bearing DOM (DON) and S-bearing DOM (DOS). This study delves into the spatial gradients and transformation mechanisms of DOM, DON, and DOS in Pearl River Estuary (PRE) sediments, China, using combined techniques of UV-visible spectroscopy, Excitation-emission matrix (EEM) fluorescence spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and microbial high-throughput sequencing. Results uncovered a distinct spatial gradient in DOM concentration, aromaticity (SUVA254), hydrophobicity (SUVA260), the content of substituent groups including carboxyl, carbonyl, hydroxyl and ester groups (A253/A203) of chromophoric DOM (CDOM), and the abundances of tyrosine/tryptophan-like protein and humic-like substances in fluorophoric DOM (FDOM). These all decreased from upper to lower PRE, accompanied by a decrease in O3S and O5S components, indicating seaward reduction in the contribution of terrestrial OM, especially anthropogenic inputs. Additionally, sediments exhibited a reduction in molecular diversity (number of formulas) of DOM, DON, and DOS from upper to lower PRE, with molecules tending towards a lower nominal oxidation state of carbon (NOSC) and higher bio-reactivity (MLBL), molecular weight (m/z) and saturation (H/C). While molecular composition of DOM remained similar in PRE sediments, the relative abundance of lignin-like substances decreased, with a concurrent increase in protein-like and lipid-like substances in DON and DOS from upper to lower PRE. Mechanistic analysis identified the joint influence of terrestrial OM, anthropogenic N/S inputs, and microbial processes in shaping the spatial gradients of DOM, DON, and DOS in PRE estuarine sediments. This study contributes valuable insights into the intricate spatial gradients and transformations of DOM, DON, and DOS within human-impacted estuarine sediments.

Enterohemorrhagic Escherichia coli (EHEC) is an important foodborne pathogen that infects humans by colonizing the large intestine. The genome of EHEC O157:H7 contains 177 unique O islands (OIs). Certain OIs significantly contribute to the heightened virulence and pathogenicity exhibited by EHEC O157:H7. However, the function of most OI genes remains unknown. We demonstrated here that EHEC O157:H7 adherence to and colonization of the mouse large intestine are both dependent on OI-97. Z3495, which is annotated as a LysR-type transcriptional regulator and encoded in OI-97, contributes to this phenotype. Z3495 activated the locus of enterocyte effacement (LEE) gene expression, promoting bacterial adherence. Deletion of z3495 significantly decreased the transcription of ler and other LEE genes, the ability to adhere to the host cells, and colonization in the mouse large intestine. Furthermore, the ChIP-seq results confirmed that Z3495 can directly bind to the promoter region of rcsF, which is a well-known activator of Ler, and increase LEE gene expression. Finally, phylogenetic analysis revealed that Z3495 is a widespread transcriptional regulator in enterohemorrhagic and enteropathogenic Escherichia coli. As a result of this study, we have gained a deeper understanding of how bacteria control their virulence and provide another example of a laterally acquired regulator that regulates LEE gene expression in bacteria.

Net-zero carbon emission target for mitigating climate change accelerates the exploitation of renewable energy, such as solar and wind, as power origin in utilities sector. However, the intermittency of renewable energy escalates the supply-demand mismatch in not only electricity sector but also water sector, as freshwater supply increasingly relies on unconventional, energy-intensive desalination that is increasingly powered by renewables. To enhance the energy-water resilience, we propose a desalination-osmotic energy storage (DOES) system, which alternates the operation of reverse osmosis (RO) for desalination and pressure retarded osmosis (PRO) for electricity generation, achieving multiple functions including freshwater production and storage, grid energy storage, and eventually bulk-scale management of freshwater and energy supply. Via innovative system design and operation integrating semi-closed (SC) and closed-circuit (CC) configurations in RO and PRO modes in the proposed DOES, energy loss arising from over-pressurization in RO and under-pressurization in PRO could be substantially reduced. As a result, DOES can achieve practical maximum energy efficiencies of >75 % for both RO desalination and PRO electricity generation, and a round-trip efficiency of >68 % when used as a grid-scale energy storage system (ESS). Apart from the quantitative analysis of energy performance, a qualitative comparison of various other performance metrics between DOES and other grid ESSs is also conducted. Given its various performance advantages as well as multi-functionality, the DOES system could be an important complement to, though not replacement of, existing grid-scale ESSs.

Multicell constructed wetlands (MCWs) on lakeshores are a prospective treatment technique. However, the factors affecting the nutrient removal performance of lakeshore MCWs at the field scale are unclear. This study chose a field-scale lakeshore MCW with the highest mass removal efficiency (approximately 49,175.12 mg m−2 day−1) for total nitrogen removal in the wet season to investigate the response of nitrogen removal and microbial distribution to seasonal shock nutrients load. The mass loading rates in the wet season were as high as 43~72 times over those in the dry season. Hence, a storage pond (SP), as a forebay retention cell, was necessary to mitigate the shock loads of the influent, which is beneficial to nitrogen removal of the MCW system. The two major genera in the sediments are heterotrophic nitrification–aerobic denitrification bacteria, and the abundance and species of the nitrogen-related functional genera were higher in the wet season than the dry season. According to the results of redundancy analysis, the hydraulic residence time (29.4%, F = 2.2, p < 0.1) and hydraulic loading rate (85.9, F = 36.5, p < 0.05) were the major factors explaining microbial community variation, instead of environmental factors (temperature, pH, and dissolved oxygen). The shock loads of influent and the periodic saturation in sediments contributed to a complicated oxygen and nitrogen nutrient exchange environment resulting in higher abundance and species of nitrogen-related microbes, which is beneficial to nitrogen removal in lakeshore MCWs. The results provided a scientific basis for the optimal design of constructed wetlands on lakeshores.

The emissions of greenhouse gases from agricultural ecosystems account for 12%of global anthropogenic greenhouse gas emissions.However,as a prominent agricultural ecosystem,the fate and mechanisms of greenhouse gases(CH4,N2O and CO2)linked with the microorganisms and agricultural emission reduction strategies are still unclear at the soil-water interface in paddy fields.This work discussed the mechanisms and influencing factors of greenhouse gas(CH4,N2O and CO2)production in paddy fields,as well as agricultural management measures to reduce emissions.Researches demonstrated that the greenhouse gas emissions at the water-soil interface in paddy fields were primarily driven by microorganisms.The soil physicochemical properties,such as soil temperature,moisture,and redox potential(Eh),profoundly influenced the composition and processes of microbial communities,thereby affecting greenhouse gas emissions.Agricultural management measures such as effective water regulation,soil nutrient management,and microbial regulation can change the flux of greenhouse gas emissions from the soil.Microbial regulation techniques such as the addition of Bacillus amyloliquefaciens,stimulation of methane-oxidizing bacteria activity,and the exploration of nitrogen-fixing bacteria containing N2O reductase genes have promising potential for greenhouse gas emissions reduction.However,the microbial mechanisms of greenhouse gas emissions from paddy fields currently primarily reply on indoor studies and lack the support of large-scale field data.The relationship between the microbial communities in rice fields and ecosystem functions,as well as the microbial control mechanisms mediated by agricultural management,are topics that have received little attention in the literature.Soil microorganisms play an important regulatory role in reducing greenhouse gas emissions from rice field.They can reduce greenhouse gas emissions by changing soil properties and altering the composition of microbial communities at the water-soil interface.This study provides new perspectives for reducing greenhouse gas emissions from rice fields and provides theoretical support for reducing greenhouse gas emissions from farmland and mitigating global warming.