Porcine enteric coronaviruses (PECs) include porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine deltacoronavirus (PDCoV). Infections with PECs can cause severe diarrhea in pigs, particularly newborn piglets, resulting in high mortality rates and posing a serious threat and economic loss to the global swine industry. Such infections induce oxidative stress to activate various transcription factors and alter their transcriptional pathways, thereby affecting cellular metabolism and the viral life cycle. This leads to cellular dysfunction and further promotes viral replication, forming a vicious cycle. The oxidative stress associated with PECs is considered one of the potential common pathogenic mechanisms. This review summarizes the information about the oxidative stress induced by infections with PECs and emphasizes that antioxidant strategies represent one of the effective approaches to counteract such infections.

Colorectal cancer (CRC), one of the most common malignancies of the digestive system, is characterized by complex pathogenic mechanisms and an overall poor prognosis. The gut microbiota and its metabolites play a dual role in CRC by modulating various forms of programmed cell death (PCD), either promoting or inhibiting tumorigenesis and influencing the tumor responses to chemotherapy and immunotherapy. This review systematically summarizes recent advances in understanding how the gut microbiota regulates CRC initiation, progression, and responses to therapies through the modulation of apoptosis, autophagy, ferroptosis, and pyroptosis. Furthermore, it discusses the potential clinical-translational implications of these findings, aiming to provide a theoretical foundation for elucidating CRC pathogenesis and developing novel therapeutic strategies targeting the gut microbiota.

Respiratory viral infections pose a severe threat to global public health security, and exploring effective strategies to prevent them is of clinical significance. The gut microbiota plays a crucial role in regulating anti-infective immunity by remodeling the immune microenvironment, maintaining the immune homeostasis and boosting antiviral defenses of the host. Conversely, dysbiosis of the gut microbiota can disrupt immune homeostasis, resulting in impaired innate immune responses and abnormal activation of adaptive immunity, thereby raising the risk of respiratory viral infections in the host. This study elaborates on the essential role of the gut microbiota in the antiviral immune response of the host across multiple aspects. (1) It thoroughly explains how the gut microbiota contributes to forming an immune defense barrier by performing physiological functions such as secreting antimicrobial peptides, metabolizing nutrients, preserving mucosal barrier integrity, and modulating immune homeostasis of the host. (2) It analyzes the antiviral immune regulatory network that involves the regulation of type I interferon responses and immune cell differentiation, all within the context of gut microbiota balance and dysbiosis. (3) It explores how probiotics exert antiviral effects through mechanisms such as inhibiting viral proliferation, improving the host’s immune response, reducing secondary infections, and restoring gut microbiota balance. Although breakthroughs have been made in understanding the ternary interaction network of the microbiota, the immune system, and viral infection, the molecular mechanisms behind its dynamic balance and precise regulation still urgently need detailed investigation. Specifically, the mechanisms of interactions between gut microbiota metabolites and host epigenetic regulation, along with the long-term protective strategies of microbiota-induced immune homeostasis against viral infection, remain to be systematically revealed through multi-omics technologies.

As a crucial group of probiotics, lactic acid bacteria (LAB) play a vital role in the gut microbial ecosystem of insects. This article comprehensively reviewed the species composition, ecological functions, and practical values of LAB in the guts of major insect orders, including Hymenoptera, Diptera, Coleoptera, Hemiptera, Lepidoptera, Blattodea, and Orthoptera. To date, multiple LAB genera including Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Enterococcus, Bifidobacterium, and Weissella were successfully identified from insect guts. The community composition of these bacteria was shaped by factors such as host phylogeny, dietary traits, developmental stages, gut microenvironment, and external ecological conditions. The LAB in insect guts not only assist the hosts in degrading recalcitrant complexes by secreting extracellular enzymes but also inhibit pathogens through the synthesis of antimicrobial substances such as bacteriocins. Additionally, they modulate host immune responses, promote growth and development, regulate host behavior, and participate in the metabolic detoxification of xenobiotics, thereby enhancing host survival and adaptability. Furthermore, insect-derived LAB held great potential in the production of resource insects, pest management, agricultural waste utilization, and green manufacturing. In summary, insect guts represent an important reservoir for the discovery and isolation of novel LAB.

The general stress response (GSR) is a global regulatory strategy developed by bacteria to adapt to diverse environmental stresses by coordinating a suite of physiological and metabolic changes, thereby enabling survival in fluctuating conditions. The alternative sigma factor RpoS (σ^S) serves as a central GSR regulator in bacteria and is crucial for bacterial responses to various stress conditions. Such regulators in bacteria are conserved, while polymorphic variations in rpoS are prevalent across numerous natural isolates and acclimated strains. This polymorphism reflects the adaptive trade-off mechanism formed by bacteria during the evolutionary process, positioning RpoS as a key model for investigating fitness trade-offs in bacteria. This review summarizes the functions and polymorphisms of RpoS and explores the potential environmental drivers underlying its polymorphism.

γ-Aminobutyric acid (GABA), a key inhibitory neurotransmitter in the central nervous system, plays a vital role in physiological functions such as promoting sleep, relieving tremors, and regulating blood pressure. Currently, a variety of microorganisms capable of synthesizing GABA have been identified, offering diverse strategic options for the biosynthesis of GABA through different metabolic pathways. This review provides a detailed summary of the major pathways—the GABA shunt pathway and the putrescine pathway—for GABA synthesis in various microorganisms. It systematically outlines the key synthases and metabolites involved in the two pathways, while comparing their synthesis efficiency and respective advantages. Furthermore, this study delves into the regulatory mechanisms underlying GABA biosynthesis in different microorganisms, along with key regulatory targets for enhancing synthesis efficiency. The work aims to establish a theoretical framework for the regulatory mechanisms of microbial-derived GABA synthesis and to provide a scientific basis for improving the efficiency of GABA biosynthesis.

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a class of secondary metabolites synthesized by the ribosomes of microorganisms and formed through a series of post-translational modifications. They have diverse structures, high stability, and antimicrobial, antiviral, anti-inflammatory or anti-tumor activities. Moreover, they are not prone to generating drug resistance, thus showcasing great potential to be applied in the fields of medicine, food, and agriculture. The genomes of microorganisms harbor a large number of biosynthetic gene clusters for RiPPs, while many of them require the producing strains to be cultivated in specific conditions or to interact with other environmental microorganisms, being the “dark matter” in the genome. Heterologous biosynthesis is an effective means to obtain novel RiPPs and make use of them. This article reviews the recent research progress in the diversity, bioactivity, genomic mining, and heterologous biosynthesis of RiPPs from microorganisms, with the expectation of providing a theoretical basis for a deeper understanding of the molecular structures and functions of RiPPs, as well as for the development and application of novel microbial active metabolites and their producers.

Microorganisms represent the largest untapped resource reservoir on the Earth, and breakthroughs in their isolation and cultivation are prerequisites for fundamental advances in the life sciences. This review focuses on recent progress in the isolation and screening technologies for bacteria, fungi, and archaea. It systematically elucidates how the development and application of cutting-edge isolation and screening technologies have enhanced the efficiency of isolating previously uncultivable and rare microbial taxa. By summarizing lineage-specific strategies—such as multi-omics targeting and single-cell precision localization for bacteria, metabolomics-guided screening and microfluidic technology for fungi, and co-culture systems coupled with extreme-condition cultivation for archaea—this review highlights the core value of interdisciplinary technology integration in bridging genomic data with in situ functional validation. Finally, the article prospectively addresses challenges in data integration and the construction of automated workflows, thereby outlining a strategic pathway for the systematic exploration of microbial resources.

Objective The engineering of the reductive glycine pathway (rGlyP) in Komagataella phaffii (syn. Pichia pastoris) represents a promising strategy for the co-utilization of methanol and CO₂. However, the efficiency of this pathway is constrained by the insufficient supply of intracellular reduced nicotinamide adenine dinucleotide (NADH), as the native alcohol oxidase (AOX) pathway generates hydrogen peroxide rather than NADH, leading to energy loss and oxidative stress. To overcome this bottleneck, this study reconstructed the methanol oxidation pathway and employed a subcellular compartmentalization strategy to optimize the carbon flux and energy metabolism. Methods Five different sources of NAD⁺-dependent methanol dehydrogenase (MDH) were screened in an aox1/aox2-deficient strain by using the growth curve and methanol utilization rate as indicators to determine the optimal MDH, and the methanol induction concentration was optimized. Subsequently, a compartmentalization strategy was employed by fusing the peroxisomal targeting signal 1 (PTS1) to MDHN1T, which targeted the enzyme to the peroxisome to spatially couple methanol oxidation with formaldehyde detoxification. Results The MDHN1T derived from Cupriavidus necator had the best catalytic performance, and the optimum methanol induction concentration was optimized to be 0.6%. Under co-utilization conditions, the engineered strain achieved a methanol consumption rate of 28.98 mg/d, with the total intracellular NAD_total pool, NADH/NAD⁺ ratio, and biomass being 1.3, 1.2, and 2.2 folds, respectively, of those in the parental strain. Conclusion This study successfully alleviates the redox cofactor imbalance in the rGlyP and enhances co-utilization of methanol and CO₂ in K. phaffii, providing a robust chassis and a theoretical basis for the development of microbial cell factories utilizing one-carbon resources.

Objective Four-carbon dicarboxylic acids are a class of important platform chemicals widely used in the food, pharmaceutical, and chemical industries. However, the efficiency of microbial fermentation for producing four-carbon dicarboxylic acids still faces challenges, mainly limited by insufficient central carbon metabolic flux and byproduct accumulation. Methods This study used Escherichia coli as the chassis strain and adopted a strategy combining rational metabolic engineering and non-rational modification to systematically optimize the four-carbon dicarboxylic acid synthesis capacity of E. coli. Results The non-cyclic glyoxylate shunt was reconstructed and the expression of key pathway enzymes was optimized to enhance the metabolic flux toward four-carbon dicarboxylic acids. The synthesis capacity of four-carbon dicarboxylic acids was enhanced by employing atmospheric and room-temperature plasma (ARTP) mutagenesis. The knockout of key genes in the acetate, formate, and lactate synthesis pathways effectively minimized carbon flux diversion, thereby enhancing the availability of oxaloacetate, the central precursor to four-carbon dicarboxylic acids. On this basis, through specific modification of terminal metabolic pathways, the engineering strain E. coli Fum02 for fumaric acid production were constructed. Finally, in a 5 L fermenter, the fumaric acid titer, yield, and productivity of the engineering strain E. coli Fum02 reached 45.2 g/L, 0.45 g/g, and 0.23 g/(L·h), respectively. Furthermore, by blocking the succinate dehydrogenase gene (sdhAB) and implementing fermentation optimization strategies, this platform strain could also be redirected toward efficient succinate production. Conclusion This study provides a reference for the metabolic engineering modification of bacteria to produce organic acids and also lays a foundation for the industrial biomanufacturing of four-carbon dicarboxylic acids.

Objective The rapid increase in wastewater discharge from animal husbandry has caused severe environmental pollution. Identifying efficient heterotrophic nitrifying-aerobic denitrifying bacteria and investigating their denitrification mechanisms are of great theoretical and practical importance for mitigating nitrogen pollution in the wastewater. Methods A strain exceling in heterotrophic nitrification-aerobic denitrification (HN-AD) was isolated and from activated sludge in pig farms. Culture conditions were optimized by response surface methodology. We evaluated the inorganic nitrogen-transforming capacity of the strain by assessing its utilization efficiency of single and mixed nitrogen sources and through nitrogen balance analysis. The completeness of the denitrification process was confirmed via gas chromatographic measurements of N₂ and N₂O. Finally, the nitrogen removal pathways and underlying mechanisms were elucidated through whole-genome analysis. Results The successfully isolated strain Klebsiella sp. WH-E exhibited excellent HN-AD capabilities. The growth conditions of the strain were optimized as follows: sodium citrate as the carbon source, 34.18 °C, initial pH 7.1, a C/N ratio of 14.53, and a shaking speed of 159.59 r/min. When the strain was cultured with ammonium, nitrate, or nitrite as the sole nitrogen source, the nitrogen removal rates were 99.80%, 81.54%, and 80.00%, respectively. Furthermore, when ammonium was the sole nitrogen source, 35.84% and 35.91% of nitrogen were converted into cellular nitrogen and gaseous nitrogen, respectively. When ammonia nitrogen was combined with nitrate nitrogen as mixed nitrogen sources, the nitrogen removal rate was 100.00%; When ammonia nitrogen was combined with nitrite nitrogen as mixed nitrogen sources, the ammonia nitrogen removal rate was 100.00%, and the nitrite nitrogen removal rate was 91.97%, respectively. Whole-genome sequencing identified several nitrogen metabolism-related functional genes, including glnB, norVWR, narGHI, nasBC, and nirBD. Conclusion Klebsiella sp. WH-E possesses three nitrogen metabolism pathways: ammonium assimilation, nitrification-denitrification, and nitrate assimilation and dissimilation. This study confirms the applicability of Klebsiella sp. WH-E for nitrogen removal from full-scale piggery wastewater and establishes a solid theoretical foundation for its engineering applications.

The gut microbiota plays a crucial role in promoting food digestion in animals. However, the impact of cross-species microbiota transplantation from donors with different dietary habits on the host food digestion capacity remains unclear. Objective To investigate the role of cross-species microbiota transplantation in regulating the digestive system adaptability, metabolic functions, reproduction, stress responses, and gut microbiota structure of the host. Methods We utilized New Zealand white rabbits (Oryctolagus cuniculus), a herbivorous species, and C57BL/6J mice, an omnivorous species, as donors and recipients of gut microbiota, respectively. The mice were allocated into three groups: a control group on a normal diet (Con), a group on a high-fiber diet (TS), and a group on a high-fiber diet supplemented with rabbit fecal microbiota transplantation (OC). This study was designed to evaluate various physiological and biochemical parameters, including body weight, food intake, absolute and relative organ weights (both wet weight and organ-to-body weight ratio), morphometric indices (length and diameter) of the small intestine, sperm concentration, and serum corticosterone level, in mice. Additionally, we performed 16S rRNA gene sequencing targeting the V3-V4 hypervariable region to characterize the composition of fecal microbiota. Results A high-fiber diet significantly increased the food intake, small intestine length, and serum corticosterone level, while significantly reducing the body weight, liver and spleen wet weights, liver/body weight ratio, spleen/body weight ratio, and sperm concentration in mice. Moreover, it increased the alpha diversity of the gut microbiota, decreased the Bacillota-to-Bacteroidota ratio, and reduced the relative abundance of probiotics (such as Ligilactobacillus). Transplantation of the gut microbiota from rabbits increased the wet weight of the epididymis and the epididymis/body weight ratio, while significantly reducing the liver/body weight ratio and the serum corticosterone level in recipient mice. Furthermore, a high-fiber diet significantly increased the relative abundance of the fiber-degrading bacterial family (Oscillospiraceae) and the gut health-associated bacterial genus (Colidextribacter). After the transplantation of rabbit gut microbiota into mice, the relative abundance of Oscillospiraceae and Colidextribacter in mice increased significantly. Conclusion The high-fiber diet has adverse effects on omnivores. Although the microbiota transplantation from herbivores does not significantly improve the host ability to digest fiber, it changes the gut microbiota structure of omnivores, playing a positive role in improving their digestion, reproduction, metabolism, and stress responses. Future research needs to further determine the optimal levels of dietary fiber for omnivores and the dosage of microbiota transplantation from herbivores, as well as their synergistic effects and underlying mechanisms in improving animal health. This study provides a reference for exploring the role of gut microbiota in animal adaptation to dietary changes in natural environments and lays a foundation for future research on improving the utilization of high-fiber foods by omnivorous domestic animals.

Objective To explore plant growth promoting rhizobacteria (PGPR) resources from the rhizosphere soil of maize in a maize-soybean rotation system and elucidate their roles in promoting the growth of maize and soybean, thus providing a theoretical basis and practical support at the microbial level for the sustainable development of agriculture. Methods Actinomycetes strains were isolated from the rhizosphere soil of maize via the dilution plating method with Gauze’s Synthetic Medium No. 1. The strains capable of secreting protease, producing siderophores, and fixing nitrogen were selected out. The isolated strains were identified by means of morphological observation and 16S rRNA gene sequence analysis. After optimization of the fermentation conditions and tests of stress tolerance, a synthetic microbial consortium (SMC) was prepared. Its growth-promoting effects on maize and soybean were evaluated through seed germination tests and pot experiments. Results A total of 105 Actinomycetes strains were isolated, five of which simultaneously exhibited the abilities of siderophore production, protease secretion, and nitrogen fixation. These strains were identified as Arthrobacter pokkalii (JM-18, JM-21), A. oryzae (JM-24), A. ginsengisoli (JM-47), and A. pascens (JM-48). They were mixed in equal proportions to form a SMC. Growth promotion assays showed that the SMC significantly improved maize seed germination and maize plant growth in pots. Specifically, the SMC increased the root length and shoot length in the seed germination assay by 120.22% and 20.94%, respectively, and it also significantly increased the plant height, root length, fresh weight, and dry weight of maize plants in pots. Moreover, the SMC markedly promoted soybean development, increasing soybean shoot length by 42.08% during seed germination. For potted soybean plants, the SMC increased the plant height, root length, fresh weight, and dry weight by 39.40%, 93.31%, 161.14%, and 163.57%, respectively. Conclusion We successfully identified five Actinomycetes strains capable of secreting protease, producing siderophores, and fixing nitrogen. The SMC constructed from these strains significantly enhances the growth of both maize and soybean. This study offers promising microbial resources for the development of efficient and environmentally friendly biofertilizers.

Objective With the widespread use and promotion of plastic film mulching on the Qinghai-Xizang Plateau, a series of issues caused by its application have also emerged. Given the fragile eco-environment of the plateau, it is necessary to investigate the effects of different types of plastic film mulching on the soil microbial community structures in farmland ecosystems. Methods Three treatments—pre-planting soil (ZQ), soil covered with conventional polyethylene mulch (CMPs), and soil covered with biodegradable mulch (BMPs)—were established. Soil physicochemical properties were measured, and high-throughput sequencing of the 16S rRNA gene and ITS region was employed to analyze microbial diversity, community structure, and their associations with environmental factors, on the basis of which the impacts of mulch types on soil microorganisms were evaluated. Results Differences in soil physicochemical factors were observed among different treatments (P<0.05). There were no significant differences in alpha diversity indices for both bacteria and fungi among the treatments, indicating that short-term plastic film mulching did not significantly alter the richness and diversity of microbial communities. The dominant bacterial phyla were Pseudomonadota, Actinomycetota, Acidobacteriota, and Chloroflexota, with most dominant genera being unclassified. The dominant fungal phyla were Ascomycota, Basidiomycota, Mortierellomycota, with dominant genera including Mortierella and Solicoccozyma. Network analysis revealed that the main drivers of bacterial and fungal community structures were pH and microplastic (MP) content, respectively. This result reflected functional differences of fungi and bacteria. Fungi, as primary decomposers, were more sensitive to MP pollution, whereas bacterial community structure was more closely related to soil pH. Functional prediction showed that, in bacteria, only the metabolism pathway within the KEGG level 1 showed a positive correlation with the mulching treatment, and no significant differences in COG functions were observed between treatments. In fungi, saprotrophic functions predominated, and their relative abundance changed significantly among treatments. Conclusion Short-term plastic mulching does not significantly affect microbial alpha diversity, but alters the community structure. Compared with conventional PE mulch, biodegradable mulch shows greater potential in enhancing soil nitrogen and organic carbon pools. However, it leads to more severe short-term MP accumulation, accompanied by the risk of pathogenic fungal enrichment. Therefore, its long-term ecological effects require further assessment.

Trees can form mutualistic symbionts with mycorrhizal fungi. Different mycorrhizal types affect the community structure of endophytic fungi by regulating tree physiology and root microenvironment, thus becoming a key link driving the interaction network between soil and microorganisms in tropical forests. However, the mechanisms by which different mycorrhizal types regulate the diversity and community composition of endophytic fungi in tropical tree roots are still not fully understood. Objective To explore the effects of different mycorrhizal types on the diversity and community structure of root endophytic fungi in tropical trees, as well as their key driving factors, systematically clarifying how mycorrhizal types affect the composition and diversity of endophytic fungal communities by regulating root traits and rhizosphere environment, and identifying the key driving factors. Methods On the basis of 3 773 sets of soil and root data collected from three research sites of Chinese Ecosystem Research Network (CERN) in Xishuangbanna tropical forest, China, we integrated and constructed a dataset at the tree species level. This dataset encompassed data of the root traits, soil physical and chemical properties, and the operational taxonomic unit (OTU) abundance of endophytic fungi in the roots of 119 trees (54 species) with arbuscular mycorrhizas (AM) and 31 trees (12 species) with ectomycorrhizas (ECM), and it was then used for the research. Results The alpha diversity of endophytic fungi in the roots of AM trees was higher than that of ECM trees (P<0.05). Mycorrhizal types affected the dominant groups of root endophytic fungi. Ascomycota had the highest relative abundance (43.17%) in the roots of AM trees, and Basidiomycota had the highest relative abundance (65.17%) in the roots of ECM trees. The co-occurrence network analysis showed that the endophytic fungal network was denser in the roots of AM trees and more modular in roots of ECM trees. Soil properties were the dominant driving factors for the endophytic fungal communities in the roots of AM trees, while the endophytic fungal communities in the roots of ECM trees were regulated jointly by root traits and soil properties. Soil phosphorus was a key factor affecting the endophytic fungal communities in the roots of AM and ECM trees. Conclusion In tropical forest ecosystems, AM drives trees to form species-rich and closely interacting endophytic fungal communities in the roots, and the assembly process is mainly regulated by soil factors. ECM trees form a specialized symbiotic fungal system, whose construction is regulated by both root traits and soil factors. In addition, soil phosphorus is the core factor driving the formation of endophytic fungal communities in the roots of the two types of trees.

Objective Fusarium wilt caused by Fusariumoxysporum f. sp. nivum is a typical soil-borne disease in watermelon production, posing significant threats. This study investigates the microbial community structures in the rhizosphere soil of healthy and Fusarium wilt-affected watermelon plants to clarify the regulatory effects of this disease on the physicochemical properties and microbial communities of rhizosphere soil. It aims to reveal the interactions between pathogen enrichment, beneficial microbial decline, and soil environmental factors, providing theoretical support for the green control of Fusarium wilt in watermelon plants by rhizosphere microbiome regulation. Methods Rhizosphere soil samples were collected from healthy plants (HT group) and Fusarium wilt-infected plants (FT group) of the watermelon variety ‘Xiaoyu No. 5’ in Shaoyang, Hunan. Physicochemical indicators including total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and available potassium (AK) were measured. Illumina high-throughput sequencing was employed to analyze the structures and diversity of microbial communities in the rhizosphere soil of healthy and disease-infected plants. Results The FT group had lower content of TP, AP, and AK in the rhizosphere soil than the HT group (P<0.05). The TN, organic matter (OM), and pH in the FT group were lower without significant differences than the HT group. The FT group had higher fungal ACE and Chao1 indices (P<0.05), higher bacterial ACE and Chao1 indices (P>0.05), and higher fungal and bacterial Simpson indices (evenness) (P<0.05) than the HT group. The abundance of Bacillota was significantly higher in the HT group than in the FT group, whereas that of Ascomycota was significantly higher in the FT group. At the genus level, the abundance of beneficial bacteria such as Neobacillus and Bacillus decreased in the FT group, while that of the pathogenic genus Fusarium increased sharply from 0.06% to 2.40%. The redundancy analysis (RDA) indicated that TN, TP, and OM were key drivers of bacterial community changes, whereas TN, OM, and AK were core regulators of fungal communities. Functional prediction suggested enhanced functions such as stress responses and energy metabolism of bacteria, alongside increased potential for functions such as plant cell wall degradation of fungi, in the diseased rhizosphere. Conclusion The occurrence of Fusarium wilt in watermelon plants leads to depletion of phosphorus and potassium in the rhizosphere soil and disrupts microbiome balance. This is manifested by the enrichment of Fusarium and the decline of beneficial bacteria (e.g., Neobacillus and Bacillus). Soil TN, OM, and AK are key environmental factors regulating this imbalance, with AK deficiency potentially serving as a pivotal link between soil environmental degradation and disease intensification. These findings provide crucial theoretical support for developing eco-friendly control strategies-potassium supplementation and stabilization alongside the targeted cultivation of beneficial microbial communities-targeting Fusarium wilt in watermelon plants.

Objective To investigate the effects of combined application of organic and inorganic fertilizers on soil nutrient content and microbial community structures and functions in soybean fields, thus providing a scientific basis for rational fertilization and high-quality, high-yield soybean production. Methods Four fertilization treatments—control (CK: no fertilization), inorganic fertilizer (CF: compound fertilizer), organic fertilizer (OF: dry chicken manure), and combined organic-inorganic fertilizers (OCF: dry chicken manure+compound fertilizer)—were established. During the experiment, soil organic matter (SOM), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), available potassium (AK), and microbial community structures and functions were measured to investigate the relationships between microbial communities and soil nutrients. Results Different fertilization treatments influenced soil nutrients in soybean fields. Compared with CK, the OCF treatment increased the soil SOM, AN, AP, and AK by 60.67% (P<0.05), 68.09% (P<0.001), 15.18 folds (P<0.001), and 59.54% (P<0.01), respectively, and it also increased soil pH. Amplicon sequencing indicated that different fertilization measures did not alter the community composition of soil microorganisms but changed the relative abundance of different phyla and genera. Compared with CK, the OCF treatment increased the relative abundance of Basidiomycota and Mortierellomycota by 5.62 folds and 4.51%, respectively, while decreasing that of Ascomycota by 38.35%. The OCF treatment reduced fungal community richness and diversity (P<0.05). The alpha diversity analysis revealed that both bacterial and fungal diversity decreased after organic fertilizer application, with fungal alpha diversity showing the most significant reduction (P<0.05). Functional prediction indicated that amino acid metabolism exhibited the highest relative abundance among metabolic pathways in bacterial communities, suggesting that the OCF treatment promoted metabolic processes centered on nitrogen assimilation and protein synthesis, facilitating bacterial participation in soil nutrient transformation. Under the OF treatment, symbiotropic fungi exhibited the highest relative abundance, which suggested that organic fertilizer promoted the ecological functions of fungi in soil nutrient cycling. Conclusion Combined application of organic and inorganic fertilizers modulates soil pH, mitigates soil acidification, and enhances soil nutrient content. Fungal communities exhibit greater sensitivity to organic fertilizer application, which significantly reduces their diversity and stimulates the proliferation of certain pathogenic fungi. Conversely, inorganic fertilizer suppresses the relative abundance of pathogenic fungi. Thus, the combined application of organic and inorganic fertilizers demonstrates distinct advantages in balancing soil nutrient supply with microbial community structure and optimizing soil microbial functional composition. This approach provides theoretical foundations and practical guidance for achieving efficient, green, and sustainable fertilization management in soybean fields.

Objective Earthworm intestines, rich in carbohydrates and organic acids, are considered potential hotspots for the horizontal transfer of antibiotic resistance genes (ARGs). However, direct evidence is lacking regarding whether reactive oxygen species (ROS) are produced under anaerobic conditions in earthworm intestines and how ROS regulate plasmid conjugation. This study aimed to investigate the contribution of organic matter metabolism to ROS generation in earthworm intestines and how ROS affected the conjugative transfer of plasmids. Methods Pheretimaguillelmi was used as a model organism to establish the anaerobic microcosm systems simulating in-situ substrate concentrations of earthworm intestines. Four treatments with glucose, lactate, acetate, and amino acids as sole carbon sources were set up. The role of ROS was verified by adding ROS scavengers. Using the fluorescent probe technology, ion chromatography, and qPCR, we determined the production levels of •OH, O₂^•-, and H₂O₂, the consumption of organic substrates, and the abundance changes of the conjugation-related genes gfp, mCherry, trfA, and trbB, respectively. Results ROS was detected in all the treatments. The glucose group showed the highest •OH, O₂^•-, and H₂O₂ yields (0.684, 0.988, and 6.371 μmol/L, respectively) on day 2, which were significantly higher than those in other groups, while the acetate group showed the lowest yields. The substrate consumption rate followed the trend of glucose>lactate>amino acids>acetate, which was consistent with the ROS generation trend. Correspondingly, the glucose group exhibited the highest abundance of gfp, trfA, and trbB (3.47×10⁶, 6.73×10⁶, and 7.86×10⁶ copies/μg DNA) and conjugation frequency (8.9×10^-4), which were the lowest in the acetate group. After ROS scavenging, the conjugation frequencies in all the treatments significantly decreased by 73%‒92%. Mantel analysis revealed that hydroxyl radical showed the most significant correlation with conjugation frequency and abundance of trfA and trbB, indicating that •OH was the core ROS driving conjugative transfer. Unclassified Enterobacteriaceae and Clostridiumsensu stricto 10 were identified as the core microbial taxa coupling ROS generation and conjugation. Conclusion Organic matter metabolism in the anaerobic earthworm intestine can significantly promote ROS generation. ROS further regulates the conjugative transfer of ARGs among microbial strains by altering the abundance of conjugation-related genes.

Vulvovaginal candidiasis (VVC) is a prevalent fungal infection affecting the female reproductive tract. Although conventional therapeutic approaches for VVC are relatively well-established, they still exhibit certain limitations. Pulsatilla decoction, a classic traditional Chinese medicine formula, has demonstrated significant clinical efficacy in the treatment of VVC. However, its precise mechanism of action remains incompletely elucidated. Objective To clarify the therapeutic mechanism of the n-butanol extract of Pulsatilla decoction (BEPD) on VVC through network pharmacology and animal experiments. Methods A mouse model of VVC was established and the therapeutic effect of BEPD on VVC was evaluated. Network pharmacology was employed to screen the potential signaling pathways of BEPD on VVC. Western blotting, immunofluorescence, immunohistochemistry, and real-time fluorescence quantitative PCR were employed to measure the changes in autophagy, apoptosis, and related pathway proteins in the vaginal mucosa of mice. Results Network pharmacology analysis identified PIK3R1 and AKT1 as key targets of Pulsatilla decoction in exerting antifungal activity against VVC. KEGG pathway enrichment analysis indicated that Pulsatilla decoction exerted its therapeutic effects on VVC by regulating the PI3K-Akt signaling pathway. Animal experiments confirmed that compared with the VVC model group, the BEPD treatment down-regulated the expression of PI3K, p-Akt, and p-mTOR, significantly up-regulated the expression of autophagy-related proteins LC3B and ATG5, significantly inhibited the expression of apoptosis-related proteins Bax and Cleaved-Caspase-3, and significantly promoted the expression of anti-apoptosis-related protein Bcl-2. Conclusion BEPD may promote autophagy and inhibit apoptosis of vaginal epithelial cells by inhibiting the PI3K-Akt-mTOR signaling pathway, thereby restoring the homeostasis of the vaginal mucosal epithelial barrier and alleviating VVC.

Objective The outer membrane protein CirA serves as a specific transporter for catecholate-type siderophores and is involved in the uptake of siderophores and other nutrients, playing a crucial role in bacterial physiology. However, its impact on bacterial antibiotic resistance remains unclear. This study aimed to investigate the role of ahcirA in the antibiotic resistance of Aeromonas hydrophila ATCC 7966 under antibiotic stress, thereby providing a theoretical basis for elucidating the molecular mechanism by which ahcirA regulates bacterial resistance. Methods With A. hydrophila ATCC 7966 as the model organism, an ahcirA knockout strain (ΔahcirA) was constructed, and its susceptibility to multiple quinolones and aminoglycosides was assessed. Quantitative proteomics was further employed to compare protein expression profiles of ΔahcirA with and without antibiotic stress. Bioinformatic approaches were adopted for the functional analysis of differentially expressed proteins. Results In the media containing enrofloxacin and norfloxacin, the growth of ΔahcirA was significantly impaired compared with that of the wild-type strain. In contrast, ΔahcirA exhibited enhanced growth in the media supplemented with kanamycin and streptomycin. Proteomic and bioinformatic analyses revealed that the deletion of ahcirA may alter bacterial antibiotic resistance by affecting the expression of proteins involved in multiple biological processes, such as small molecule metabolism, and by modulating the expression of antibiotic resistance genes. Conclusion CirA plays a significant role in the antibiotic resistance of A. hydrophila. Its absence influences bacterial susceptibility to different classes of antibiotics by regulating the expression of diverse functional proteins and antibiotic resistance genes.

Objective To investigate the changes in gut microbiota, serum metabolites, and differentially expressed genes (DEGs) in the lung tissue of the mouse model of pulmonary fibrosis and explore the potential associations via multi-omics analysis. Methods A mouse model of pulmonary fibrosis was established by the dynamic inhalation exposure method and evaluated. Metagenomic sequencing was performed to analyze the microecological changes in cecal contents. Untargeted metabolomics was employed to detect serum metabolite alterations, and transcriptomic sequencing was conducted to profile DEGs in the lung tissue. Bioinformatics methods were comprehensively used to explore correlations and potential functional modules among differential microbial taxa, metabolites, and genes. Results Pathological changes of pulmonary fibrosis were successfully induced in the model mice, accompanied by the upregulated expression of transforming growth factor-beta (TGF-β), tumor necrosis factor-alpha (TNF-α), and fibrosis-related genes in the lung tissue. Omics results indicated the presence of gut microbiota dysbiosis, serum amino acid metabolic disorder, and lung transcriptome remodeling in the model mice. Correlation analysis demonstrated that the four differential bacterial species were strongly correlated with multiple serum metabolites, among which Akkermansia muciniphila and Ligilactobacillus murinus were jointly associated with 22 differential metabolites. A cross-omics network was constructed with these 22 differential metabolites and DEGs. Topological analysis identified five key subnetworks: (1) Inosine triphosphate serves as a phosphate donor and is converted to inosine diphosphate via multiple pathways; (2) Uridine triphosphate (UTP) undergoes an amination reaction to form cytidine triphosphate (CTP); (3) Serine/threonine-protein kinase 11, Fas-activated serine/threonine kinase, and cyclic GMP-dependent protein kinase act as core kinase nodes; (4) The reaction between serine and homocysteine bridges the metabolic pathways of methionine and cysteine; (5) Prostaglandin H₂ is catalytically converted into thromboxane A₂. Conclusion There are significant statistical correlations among gut microbiota, serum metabolites, and DEGs in the lung tissue in the mouse model of pulmonary fibrosis. We identify the core association network and potential functional modules, which provide references for the subsequent mechanism exploration of pulmonary fibrosis.

Objective To determine the cause of death of an adult crocodile in the Alligator sinensis Management Center in Anhui Province. Methods Bacteria were isolated from the heart, liver, lung, and spleen via the culture method, and the isolates were identified by morphological observation, biochemical tests, and molecular biological methods. Furthermore, the mucus phenotype was determined by means of the string test. Multilocus sequence typing (MLST) was conducted on the basis of seven housekeeping loci. Virulence gene analysis, pathogenicity test, drug resistance gene analysis, and antimicrobial susceptibility testing were conducted to clarify the pathogenicity and drug resistance of the isolates. Results The pathogenic bacteria isolated from the four organs were morphologically consistent Gram-negative bacilli. Through biochemical tests and 16S rRNA gene and khe sequencing, the isolates were identified as Klebsiella pneumoniae YZE01, capsular serotype K2. String test showed that the strain was hypermucinous K. pneumoniae, and MLST analysis showed that the strain belonged to sequence type 25 (ST25). The strain carried six virulence genes: fimH, entB, rmpA, rmpA2, mrkD, and wabG. Pathogenicity tests showed that some of the tested mice died within 24 h after infection with YZE01, and the same strain was isolated from the heart, liver, lung, and spleen. The lung tissue of infected mice showed hemorrhage and congestion lesions to different degrees. In addition, RT-qPCR revealed that the transcript levels of IL-1β, IL-6, IL-8, and TNF-α in the lung peaked at 12 h post-infection and then declined. The strain carried three drug resistance genes (blaSHV, armA, and ermB), and it was not sensitive to cephalexin, cefazolin, ampicillin, streptomycin, gentamicin, erythromycin, roxithromycin, and clindamycin. Conclusion The isolated strain K. pneumoniae YZE01 carries a variety of virulence genes and has strong pathogenicity and drug resistance. It is considered as a major cause of death in A. sinensis. The findings are conducive to the prevention and control of diseases in A. sinensis.

Objective To investigate the function of ring finger protein 31 (RNF31) in the replication of foot-and-mouth disease virus (FMDV) and to provide a theoretical basis for the research on the molecular mechanism by which the host protein RNF31 regulates FMDV replication. Methods CRISPR/Cas9 gene editing was employed to design two sgRNA sequences in the exon segment of RNF31, and recombinant plasmids were constructed by ligation with the pX459-puro vector. The recombinant plasmids pX459-RNF31-sgRNA were transfected into PK-15 cells, followed by screening under the action of puromycin to obtain the cell lines with RNF31 gene knockout. The effect of RNF31 gene knockout on FMDV replication was detected by Western blotting, RT-qPCR, and TCID₅₀ methods. Results Compared with wild-type cells, the knockout of RNF31 significantly increased the protein level, mRNA level, and virus titer of FMDV. Conclusion We successfully construct the cell lines with RNF31 gene knockout and prove that RNF31 plays a key role in the replication of FMDV. This result provides data support for further research on the mechanism by which RNF31 inhibits FMDV replication.

Objective To analyze the expression profile of the β-glucan-binding protein (Acβ-GBP) gene of Apis cerana cerana in response to Ascosphaera apis infection and to investigate the impacts of Acβ-GBP knockdown on the larval mortality and the incidence of chalkbrood disease following A. apis infection. These findings will provide a foundation for further functional research. Methods The sequence and structural characteristics of Acβ-GBP were analyzed via bioinformatics approaches. RT-qPCR was employed to investigate the expression profiles of Acβ-GBP in the larval midgut following A. apis infection. Furthermore, RNA interference (RNAi) was utilized to explore the impacts of Acβ-GBP on the larval mortality and the incidence of chalkbrood disease. Results The CDS length of Acβ-GBP was 1 440 bp, encoding a protein with a molecular weight of 54.68 kDa and a grand average of hydropathicity value of -0.22, which contained a typical transmembrane domain and signal peptide. Phylogenetic analysis revealed that β-GBP of A. c. cerana, Apis florea and Apis dorsata clustered into a single major clade. After A. apis infection, the expression level of Acβ-GBP in the midgut of A. c. cerana worker larvae was downregulated at 1-3 days post-infection (dpi) (P<0.05). Following RNA interference (RNAi)-mediated silencing of Acβ-GBP, its expression level was lower than that in the ds-egfp group at 2 and 3 dpi (P<0.01). The cumulative larval mortality and the incidence of chalkbrood disease both increased over the infection time, and the overall mortality was higher than that of the control group (P<0.000 1). Conclusion Acβ-GBP was capable of responding to A. apis infection, and knockdown of Acβ-GBP expression significantly impaired the resistance of honeybee larvae to A. apis. Collectively, β-GBP acts as an important immune recognition protein in A. c. cerana, and plays an important role in defending against fungal invasion.

Objective To investigate changes in ArfGAP with GTPase domain, ankyrin repeat and PH domain 2 (Agap2) expression during hepatic fibrosis progression following hepatitis E virus (HEV) infection and preliminarily explore the association between chronic HEV infection and Agap2 expression. Methods A BALB/c mouse model of HEV infection was established through inoculation in tail vein and subjected to RNA sequencing. HEV infection and Agap2 expression in the liver tissue were detected via immunohistochemistry, immunofluorescence assay, and real-time qPCR. Results Agap2 expression was upregulated following HEV infection (24 hpi group: P=0.000 3, 48 hip group: P=0.001 9). Chronic HEV infection induced hepatic fibrosis in mice, and Agap2 expression in the mouse liver was positively correlated with HEV load (r=0.797 4, P<0.000 1). Similarly, in vitro experiments demonstrated that Agap2 expression was upregulated in HEV-infected Huh 7.5.1 cells (r=0.968 3, P=0.002 4) and LX-2 cells (r=0.683 5, P=0.006 5), showing a positive correlation with HEV load. Conclusion The results demonstrate that Agap2 expression is positively correlated with HEV load during hepatic fibrosis progression after chronic HEV infection. Agap2 may serve as a potential molecular target for the treatment of HEV-associated hepatic fibrosis.

Objective The immunoinflammatory response induced by spinal cord injury is a key factor hindering the recovery of neurological functions. Recent studies have shown that gut microbiota dysbiosis can participate in the immune regulation of the central nervous system through the gut-spinal cord axis. This study aims to explore whether curcumin can exert its protective effect on spinal cord injury by reshaping the gut microbiota and thereby regulating the local Treg/Th17 balance in the spinal cord. Methods Female Sprague-Dawley rats weighing 200‒220 g were randomly assigned into the sham operation group, spinal cord injury group, curcumin group, fecal microbiota transplantation group, fecal microbiota transplantation+ curcumin group, and fecal microbiota transplantation+curcumin+GPR inhibitor group. Neurological function recovery was evaluated based on the Basso-Beattie-Bresnahan motor function score and gait analysis. Histopathological changes in the injured area were observed via hematoxylin-eosin staining, Nissl staining, and Luxol Fast Blue staining. RT-qPCR, ELISA, and Western blotting were employed to quantify the expression levels of key transcription factor forkhead box protein 3 (FOXP3) for Treg cells, anti-inflammatory cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β1, as well as key transcription factor retinoic acid receptor-related orphan receptor gamma t (RORγt) for Th17 cells and pro-inflammatory cytokines IL-17 and IL-6 in the spinal cord of each group. Results Compared with the spinal cord injury group and fecal microbiota transplantation group, the curcumin group and fecal microbiota transplantation+ curcumin group showed the most significant improvement in neurological function, specifically manifested by significant increases in BBB motor function scores and gait coordination, along with a marked reduction in the scope of spinal cord injury. At the molecular level, the two groups showed significantly upregulated gene and protein levels of FOXP3, IL-10, and TGF-β1 and significantly inhibited expression of RORγt, IL-17A, and IL-6 in the spinal cord tissue. This suggests that after curcumin intervention in the gut microbiota, the immune balance shifted toward a Treg-dominated anti-inflammatory state. Notably, the aforementioned beneficial effects of curcumin-modified gut microbiota were reversed after combined use of the GPR inhibitor. Conclusion This study indicates that curcumin can act on the gut microbiota to promote the recovery of motor function after spinal cord injury. Curcumin may exert the effect by activating the GPR signaling pathway, thereby upregulating Treg viability, inhibiting Th17 differentiation, and ultimately correcting the Treg/Th17 imbalance. This provides new experimental evidence and application value for using curcumin and its modified gut microbiota as an adjuvant therapeutic strategy for spinal cord injury.

Objective To establish a mouse model that effectively simulates the key clinical features of porcine Senecavirus A (SVA) infection, providing a crucial experimental tool for elucidating its pathogenesis and evaluating prevention and control products. Methods Five-week-old SPF C57BL/6J wild-type (WT) mice and type I interferon receptor-deficient (C57BL/6J ^IFNR-/- ) mice were inoculated via intraperitoneal, subcutaneous, and intramuscular routes. Blood and tissue samples were collected on days 1, 3, and 5 post-infection (dpi) for analysis of gross pathology, histopathology, viral load, and dynamic determination of inflammatory cytokines at the mRNA level. Results Compared with the mock-infected control group, both mouse strains developed gross lesions (e.g., swollen inguinal lymph nodes, yellowish livers, splenomegaly) and histopathological lesions (e.g., cortical disintegration of lymph nodes, hepatocellular necrosis, atrophy of splenic white pulp, and renal tubular necrosis). However, these lesions were more severe in C57BL/6J ^IFNR-/- mice. Viral RNA was widely distributed in tissues of both groups but was significantly higher in the C57BL/6J ^IFNR-/- group. Notably, viremia was undetectable in WT mice, whereas in C57BL/6J ^IFNR-/- mice, the virus was detected in whole blood as early as 1 dpi, peaked at 3 dpi, and then declined rapidly. Inflammatory cytokine analysis revealed significantly higher mRNA levels and protein levels of IL-1β and IL-6 in C57BL/6J ^IFNR-/- mice than in WT mice. Conclusion The C57BL/6J ^IFNR-/- mouse model successfully simulates, for the first time, the transient viremia characteristic of porcine SVA infection. It comprehensively replicates key features, including the multi-organ viral distribution, high viral load, and self-limiting recovery, providing a more effective animal model for delving into the pathogenic mechanism of SVA and evaluating vaccines and antiviral drugs.

Objective The effects of the helper strain (Priestia endophytica)1-112 on the growth of Ketogulonicigenium vulgare and the biotransformation of 2-keto-L-glonic acid (2-KLG) remain unclear. In this study, we cultured the helper strain in different media to study the mechanisms of the growth- and 2-KLG biotransformation-promoting effects of the helper strain on K. vulgare. Methods We used different media (minimal, mixed, and fementation media) to culture the helper strain and investigated the effects of the strain on the growth and 2-KLG biotransformation of K. vulgare. The differently expressed genes (DEGs) and associated metabolic pathways in the helper strain cultured in different media were analyzed by transcriptomics to screen the key factors in the co-culture system. The effects of key factors on the growth and 2-KLG biotransformation of K. vulgare were evaluated to explore their roles in the co-culture system. Results Strain 1-112 cultured in the minimal medium lost or reduced the ability to promote 2-KLG production, while it retained the ability to promote the growth of K. vulgare. This result indicated that the helper strain promoted 2-KLG biotransformation through two distinct mechanisms. There were 1 859 DEGs in strain 1-112 cultured in fermentation medium in comparison with the minimal medium, and the DEGs were significantly enriched in the pathways such as nicotinate and nicotinamide metabolism, carbon metabolism, arginine and proline metabolism, and amino acid biosynthesis. In addition, the helper strain cultured in the minimal medium containing some key factors could restore the ability to promote 2-KLG production. Glycine, proline, biotin, and nicotinic acid were found to be essential for promoting K. vulgare growth, whereas glycine, threonine, biotin, and nicotinic acid played critical roles in enhancing 2-KLG biotransformation. Conclusion The helper strain promoted the growth and 2-KLG biotransformation of K. vulgare through different mechanisms.

Objective In view of the production and environmental issues caused by excessively high nicotine content in upper tobacco leaves, this study aims to decipher the molecular mechanism of nicotine degradation by an efficient nicotine-degrading strain Pu17 screened out in the previous study via genomic approaches. Methods The taxonomic status of the strain was determined by average nucleotide identity (ANI) analysis. Whole genome sequencing and annotation were employed to clarify the nicotine metabolic pathway. Key intermediates during degradation were detected by MS/MS. Live plant trials were conducted to explore the optimal application method for nicotine reduction. Results Phylogenetic analysis revealed an ANI value of 96.51% between Pu17 and Peanarthrobacter ureafaciens, identifying Pu17 as a strain of P. ureafaciens. The genome of Pu17 was 4.47 Mb in length, with the G+C content of 63.34%, encoding 4 155 proteins. Functional annotation and comparative genomics identified unique gene clusters related to heavy metal resistance, cell surface synthesis, and metabolic potential in Pu17, which constituted its environmental adaptation strategy. Metabolite analysis detected key intermediates such as 6-hydroxypseudooxynicotine. This result, combined with that of genomic analysis, confirmed that Pu17 degraded nicotine via the pyridine pathway, with key genes (e.g., nboR, mao, and 6-hlno) primarily located on plasmids. Efficacy evaluation demonstrated that the Pu17 fermentation broth effectively reduced nicotine content in tobacco plants through both foliar spraying and root irrigation, achieving a maximum degradation rate of 14.00% in live leaves. Conclusion This study systematically elucidates the molecular mechanism and application potential of P. ureafaciens Pu17 for nicotine degradation from genomic, metabolomic, and application perspectives. It provides a theoretical basis and microbial resources for the development of bioremediation technologies for tobacco waste and harm reduction.

Objective To construct a recombinant Escherichia coli strain for the expression of the bacteriophage-derived lytic enzyme Lys162, an efficient and broad-spectrum recombinant enzyme, thus providing a technological foundation for developing novel antimicrobial agents. Methods On the basis of the whole-genome sequencing data of bacteriophage pEC.M2929.1AR.1, the protein structure was predicted via bioinformatics tools, and molecular docking analysis was performed to evaluate the substrate-binding affinity. The expression vector pET28a(+)-Lys162 and the engineered E. coli BL21(DE3) expression system were constructed. Lys162 was further assessed for its environmental stability, in vitro antibacterial activity, and lytic spectrum. Results Structural analysis predicted that Lys162 was an N-acetylmuramidase-type lytic enzyme containing a conserved catalytic domain. Molecular docking confirmed its high-affinity binding to peptidoglycan. The enzyme was expressed in a soluble form in E. coli BL21(DE3) and purified to reach a concentration of 1.89 mg/mL. In vitro assays demonstrated that Lys162 at 125 μg/mL exhibited significant lytic activity against E. coli M2929.1AR, along with potent lytic effects against multiple pathogenic bacteria including Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter spp. The enzyme retained stable activity within a pH range of 4.0-11.0 and at temperatures between 4 ℃ and 60 ℃. Conclusion Lys162 transcends the host specificity of its parental phage, demonstrating broad-spectrum antimicrobial activity and considerable environmental adaptability. Its synergistic effect with EDTA suggests a practical strategy for performance optimization. These results establish a foundation for developing novel enzymatic antimicrobials to address challenges associated with bacterial antibiotic resistance.

Objective Transient receptor potential vanilloid 4 (TRPV4), a non-selective cation channel, is deeply involved in the physiological and pathological regulation of multiple organ systems, while the comprehensive influencing mechanism of its mutation on animal intestines and intestinal flora is not clear. This study explored the regulatory effects of Trpv4 exon 8 c.1491+1G>A mutation on intestinal barrier integrity and flora-metabolic microenvironment in mice, aiming to provide an experimental basis for analyzing the interaction mechanisms between host genes and intestinal flora. Methods Trpv4 exon 8 c.1491+1G>A gene-edited mice previously constructed in our laboratory were taken as the research objects, and the expression levels of Trpv4 and TRPV4 in the intestinal tissue were determined by qPCR and Western blotting, respectively. Pathological sections were prepared for observation of the structural changes of the intestinal tissue. The 16S rRNA gene high-throughput sequencing was conducted to reveal the structural differences of intestinal flora. Non-targeted metabolomics based on LC-MS was employed to examine the changes of fecal metabolites, and the correlations between flora and metabolites were analyzed. Results Trpv4 editing led to the abnormal expression of Trpv4 and TRPV4 in the intestinal tissue of mice, which resulted in the structural abnormality of the intestinal tissue and the impairment of intestinal barrier function. In addition, the gene-edited mice exhibited an imbalance in intestinal flora, with significantly increased relative abundance of Bacteroidota, a significantly decreased Bacillota/Bacteroidota (F/B) ratio, and reduced abundance of common commensal bacteria such as Staphylococcus. Metabolomic analysis indicated that the gene-edited mice presented disordered lipid metabolism and abnormalities in immune-related metabolites. The abundance of Bacteroidota was positively correlated with lipid metabolites, while that of Desulfovibrio and Enterobacter was negatively correlated with lipid and immune metabolites. Conclusion Trpv4 exon 8 c.1491+1G>A gene-edited mice exhibited impaired intestinal barrier function, along with alterations in intestinal flora structure and the metabolic microenvironment. This study provides basic data for elucidating the interactions between specific gene mutations and the gut microbiota and offers theoretical support for the development of diagnostic and therapeutic strategies for Trpv4-related diseases.

Listeria monocytogenes, as a major causative agent of foodborne illness outbreaks, poses a serious threat to food safety and public health. In complex foodborne pathogen environments, the specific and effective detection methods for L. monocytogenes are crucial. Objective To develop a novel recombinase-aided amplification-exonuclease (RAA-exo) assay for detecting L. monocytogenes. Methods Multiple RAA primer and probe sets targeting hly were designed, and the optimal primer set was selected based on nucleic acid amplification efficiency. The reaction system was rigorously optimized, focusing on the concentrations of A buffer, B buffer, and RAA primers and probe. Results The optimized RAA-exo assay showed a limit of detection (LOD) of 0.5 copies/μL for recombinant plasmids and 10 CFU/mL for L. monocytogenes suspensions. The assay demonstrated high specificity, selectively detecting L. monocytogenes without cross-reactivity to other common foodborne pathogens, including Salmonella, Escherichia coli, Staphylococcus aureus, Bacillus cereus, or other Listeria species (L. ovinae, L. seeligeri, and L. innocua). In a validation study using 44 pork samples, the RAA-exo assay results were in complete agreement with those of the real-time fluorescence PCR internal standard method outlined in the industry standard SN/T 5224—2019. Conclusion The developed RAA-exo assay exhibits high sensitivity and specificity, requires minimal hands-on time, and achieves detection within 20 min at 37 °C. Therefore, the assay is suitable for rapid, on-site testing, serving as an efficient and convenient tool for L. monocytogenes detection, with promising applications in food safety monitoring.

Objective To prepare reference material (RM) for positive serum specific for genotype Ⅱ African swine fever virus (ASFV) for serological detection, quality control, and proficiency testing (PT). Methods The anti-serum collected from specific pathogen-free (SPF) swine immunized with inactivated genotype Ⅱ ASFV was used as raw material for the preparation of RM. Indirect enzyme-linked immunosorbent assay (iELISA) was employed to evaluate the purity, specificity, homogeneity, and stability of RM. In addition, RM was characterized by nine laboratories and applied in clinical trials by three laboratories. Results A total of five hundred bottles of RM for positive serum specific for genotype Ⅱ ASFV strain HLJ/18 were successfully prepared. The results indicated that the RM we prepared was pure, homogenous, and free of exogenous virus contamination, showing good specificity, homogeneity, and stability. The RM was stable for at least 18 months when it was stored at -20 ℃ and for at least 7 days at 4 ℃, 25 ℃, and 37 ℃. The characterization by the nine laboratories showed that the RM was positive for antibodies against genotype Ⅱ ASFV. Conclusion The positive serum specific for genotype Ⅱ ASFV strain HLJ/18 has successfully been prepared, providing critical material for ASF detection and diagnosis.

Nitrogen deposition is a major driver shaping the structures and functions of forest ecosystems worldwide. When nitrogen inputs exceed ecosystem critical loads (CLs), significant changes in the diversity and abundance of understory herbaceous plants can occur. This study aims to systematically compile and integrate critical load data for understory herbaceous plants in response to nitrogen deposition across three mycorrhizal types: arbuscular mycorrhiza (AM), ectomycorrhiza (ECM), and mixed arbuscular-ectomycorrhizal forests (AM+ECM), in forests. By establishing a dedicated and standardized database, this work facilitates comparisons of herbaceous plant responses to nitrogen inputs among different mycorrhizal types in forests and provides a scientific basis for assessing the impacts of nitrogen deposition on forest microbe-plant systems. On the basis of the published literature and the global nitrogen deposition critical load database developed by Wilkins et al., relevant data were systematically collected, screened, and standardized to construct the Database of Critical Loads of Nitrogen Deposition for Understory Herbaceous Plants across Different Mycorrhizal Types in Forests. All critical load values were consistently derived via the threshold indicator taxa analysis (TITAN) method. A rigorous quality control workflow was applied, including cross-validation of mycorrhizal types, outlier detection and treatment, and data standardization. The database contains 3 592 standardized records. The core data table includes the following fields: Latin name of herbaceous plant species, forest alliance, mycorrhizal types (AM, ECM, or AM+ECM), species-level critical load values (zenv.cp) estimated by TITAN with corresponding bootstrap uncertainty intervals (5th, 10th, 50th, 90th, and 95th percentiles), response direction (increase or decrease in abundance), purity and reliability metrics, community-level change points (CCP), and associated environmental metadata. The database covers the three major mycorrhizal types as well as graminoid and non-graminoid herbaceous functional groups in forests. This database represents the first large-scale, standardized database explicitly focusing on the relationships among mycorrhizal types, understory herbaceous plants, and nitrogen deposition critical loads in forests. Its standardized structure, transparent metadata, and stringent quality control procedures ensure its reliability for future research and applications, including nitrogen deposition risk assessment, comparative analyses of mycorrhizal functions, ecological model parameterization, and the formulation of biodiversity conservation strategies.