Objective: Hyperuricemia represents a globally prevalent metabolic disorder exhibiting a consistently increasing incidence rate, characterized by limitations in conventional therapeutic approaches, including significant hepatotoxicity and nephrotoxicity, as well as suboptimal patient compliance. Consequently, bacterial strains demonstrating high-efficiency uric acid degradation capabilities are screened and isolated from the intestinal microbiota of healthy human donors, in order to identify novel microbial resources and elucidate the underlying metabolic pathways and critical environmental regulatory mechanisms. Methods: The initial isolation was performed utilizing a specialized solid screening medium with a high uric acid concentration of 3 g/L. The formation of a transparent zone around bacterial colonies was the primary indicator of uric acid catabolic activity. Putative degraders were subsequently subjected to a thorough morphological characterization and definitive identification via 16S ribosomal RNA (rRNA) gene sequencing analysis. Results: Through this systematic screening approach, a single bacterial isolate exhibiting exceptional uric acid degradation capacity, designated strain nf-5, was successfully isolated and unambiguously identified as Escherichia coli. Further rigorous investigation into the metabolic functionality and environmental responsiveness of Escherichia coli nf-5 reveals that its uric acid degradation efficiency was profoundly modulated by specific physicochemical and nutritional parameters. Dissolved oxygen concentration constitutes a major determinant, with significantly superior degradation performance consistently observed under fully aerobic cultivation conditions compared to anaerobic or microaerophilic conditions. The nutritional composition of the growth medium also exerts a substantial regulatory influence. The maximum level of uric acid degradation activity, quantified at 79.8%, was achieved when strain nf-5 was cultured aerobically in brain heart infusion (BHI) broth. Reductions sodium chloride (NaCl) concentration in the BHI base, were correlated with measurable enhancements in uric acid metabolic activity. Conversely, supplementing with glucose at concentrations equal to or exceeding 5 g/L induced a pronounced inhibitory effect on the catabolism of uric acid by strain nf-5. This inhibition manifests not merely as reduced degradation rates but, critically, as a build-up of uric acid in the culture medium, indicating a potential shift in metabolic flux or repression of degradative enzymes. By contrast, adding glycerol at concentrations between 0.25% and 1% (m/V) yielded a stimulatory effect, reproducibly enhancing the rate and extent of uric acid degradation compared to glycerol-free controls. Conclusions: These collective findings constitute the first definitive report on the efficient degradation of uric acid by a strain of Escherichia coli derived from the human intestinal tract. Elucidating this phenotype, alongside demonstrating its dependence on key environmental variables-particularly dissolved oxygen tension, NaCl concentration, and the availability of specific carbon sources such as glucose and glycerol-provides crucial foundational knowledge. The strain nf-5 emerges as a compelling microbial resource candidate for developing novel, targeted microecological therapeutic strategies aimed at ameliorating hyperuricemia, offering a potential alternative or addition to existing treatments that are burdened by adverse effects. Furthermore, the detailed documentation of how environmental factors modulate uric acid metabolism within this specific gut bacterium significantly advances our mechanistic understanding of how the complex gut microbial community may intrinsically influence the systemic uric acid homeostasis in the host. This opens up new avenues for researching microbiota-directed interventions for metabolic disorders associated with dysregulated purine metabolism. This work therefore provides both a tangible microbial tool and deeper mechanistic insights into the intricate relationship between the functionality of gut microbiota and uric acid metabolism.

Type VI collagen is an important component of the extracellular matrix, primarily distributed at the dermal-epidermal junction. It plays a crucial role in maintaining the integrity of skin structure by forming a microfiber network, and is involved in cell adhesion, mechanical signal transduction, and tissue repair. This study aims to prepare recombinant human-like type VI collagen efficiently using a prokaryotic expression system (Escherichia coli). The amino acids 1 489-1 518 of the human type VI collagen α5 chain were selected and a polymeric structure was formed by repeating the unit sequence 7 times as a target protein. Following codon optimization, they were synthesized into the expression vector pET-28a and transformed into E. coli BL21. The expression conditions were optimized further to obtain stable, and functional recombinant proteins. The recombinant protein was identified by SDS-PAGE and Western blot analysis. It was then purified using affinity chromatography, and its biological activity and protective and repair effects on UV-induced photoaging of human immortalized epidermal cells (HaCaT), as well as the underlying mechanism, were evaluated. A photoaging model was constructed by irradiating the skin with a dose of 20 mJ/cm² to simulate the damage caused by photoaging. Cell viability was detected by the CCK-8 assay, and the mRNA expression levels of the inflammatory factors, Collagen Ⅰ, Collagen Ⅲ, elastin and the matrix metalloproteinase MMP-1 in cells were detected by RT-qPCR. The results showed that the E. coli expression system successfully expressed functional human-like type VI collagen. UV irradiation led to a decrease in HaCaT cell viability. Following treatment with recombinant collagen, the ROS levels decreased, and the expression of IL-8, TNF-α, and IL-1β was downregulated, resulting in reduced MMP-1 secretion. The expression of genes related to extracellular matrix synthesis was upregulated. This recombinant protein not only retained the biological characteristics of promoting cell migration and matrix adhesion but also exhibited multiple functional characteristics, such as scavenging free radicals and inhibiting the expression of inflammatory factors. These properties significantly alleviated UV-induced photoaging damage to cells. This study provides a theoretical basis for developing anti-aging biomaterials using type VI collagen, which has significant potential applications in skin tissue engineering and functional cosmetics.

Objective: To analyze the catalytic function of XmTPS, an unknown terpene synthase gene from the fungus Xylaria multiplex, and to predict and analyze the three-dimensional structure and key active sites of its encoded protein. Method: The XmTPS gene was obtained through chemical synthesis. Bioinformatics tools were used to analyze its physicochemical properties, conserved structural domains, and phylogenetic relationships. An overexpression vector for XmTPS was constructed by homologous recombination, and the recombinant protein was then expressed heterologously in Saccharomyces cerevisiae. The target protein was purified using a nickel affinity column, followed by in vitro enzymatic activity assays. Homology modeling and molecular docking techniques were employed to predict the three-dimensional structure of the XmTPS protein and analyze its key active sites. Result: The full-length cDNA of the XmTPS gene is 1 095 base pairs (bp) long, and encodes 364 amino acids with a predicted molecular weight of 41.58 kDa and a theoretical isoelectric point (pl) of 5.72. XmTPS is an unstable, hydrophilic protein. A phylogenetic analysis showed that XmTPS belongs to the monoterpene synthase family. The purified XmTPS protein can catalyze the conversion of geranyl pyrophosphate (GPP) into the linear monoterpene geraniols. It can also use farnesyl pyrophosphate (FPP) as a substrate to synthesize the linear sesquiterpene farnesol. The three-dimensional structural model of XmTPS, as predicted by AlphaFold2, exhibited the typical α-helical folding features of class I terpene synthases, and the Ramachandran plot revealed that the model was of high quality, with 93.1% of the amino acids located in the most favored region. Further molecular docking and protein-ligand interaction analyses predicted the key active sites of XmTPS. Conclusion: The catalytic function of XmTPS from X. multiplex was successfully elucidated, and the active sites of the encoded enzyme were analyzed, which provides a novel genetic resource for efficiently producing geraniol through microbial biosynthesis.

Objective: To explore how protein lysine acetylation (KAc) modification and the increased utilization of the amino acid precursor L-glutamic acid affect the production of L-arginine by Corynebacterium crenatum. Methods: The cobB gene was knocked out using scarless technology to increase the intracellular KAc level, while the cg3035 gene was overexpressed to enhance the utilization of the precursor L-glutamic acid. The influence of knocking out the cobB gene on the protein KAc level was preliminarily analyzed by Western blot and HPLC/MS/MS, and the changes in the acetylation sites of specific proteins were identified. Additionally, the effect of acetylation modification on enzyme activity was verified by performing an ArgF point mutation. Results: A strain that increases L-arginine yield was successfully constructed, increasing its yield by 53.8%. Knocking out cobB significantly altered the dynamic pattern of protein KAc modification. By HPLC/MS/MS, identification of the 48 kDa band at 84 h showed that the acetylation levels of enzymes in the arginine synthesis pathway, such as ArgC and ArgF, and key enzymes in the TCA cycle, were significantly upregulated. The K281Q and K294Q mutations in the ArgF enzyme reduced its activity by 5.14% and 13.34%, respectively, indicating that an increase in acetylation level does not necessarily enhance enzyme activity. Conclusion: By increasing the protein KAc level and optimizing the supply of precursors, the production of L-arginine by Corynebacterium crenatum can be significantly promoted. Knocking out the cobB gene regulates the efficiency with which arginine is synthesized by altering the levels at which arginine pathway enzymes and key enzymes in the TCA cycle are acetylated. This provides a new molecular breeding strategy for the metabolic engineering modification of industrial strains.

Chronic rhinosinusitis (CRS) is a clinical syndrome arising from multifactorial causes, including genetic, environmental, and lifestyle factors, which can significantly impair patients’ quality of life and increase the healthcare burden on society. Staphylococcus aureus (SA), a common pathogenic bacterium, plays a significant role in the development and progression of CRS. It may mediate type 2 helper T cell (Th2) immune responses and release inflammatory cytokines, leading to persistent chronic inflammation and recurrent exacerbations. Furthermore, given the growing challenge of bacterial antibiotic resistance, phage therapy shows promising potential as a treatment for SA infections. This article will explore the role of SA and its mechanisms in the pathogenesis of CRS. The therapeutic potential of bacteriophages in disease prevention and treatment is a particular focus.

Ensuring food safety requires the rapid detection of food-borne pathogens on site. Although conventional testing can be highly accurate, the process is lengthy, time consuming, and and labour-intensive, which cannot cope with the current level of demand. Therefore, efficient rapid testing technologies, remain urgently needed. Point-of-care testing (POCT) platforms are proving to be a promising solution. This article introduces the application of nucleic acid target isothermal amplification technology in the rapid, on-site detection of foodborne pathogens, and suggests aeras for future POCT platform research on foodborne pathogens to ensure food safety.

Pigments can be categorized as either synthetic or natural, and they play a significant role in many different fields. Interest in natural alternatives has increased due to the limitations of synthetic pigments in terms of safety and environmental sustainability. As a category of natural pigments, microbial pigments not only possess diverse biological activities but also offer an enhanced safety profiles, aligning with the growing demand for safe, efficient, and multifunctional colorants. They demonstrate considerable potential for development and utilization in various industries. This review summarizes recent advances in the biosynthesis of microbial pigments and their associated safety evaluations, as well as their applications in medicine, food production, textiles, cosmetics, and agriculture. It also discusses the current challenges and the strategies developed in response, as well as future directions for the development of microbial pigments.

L-threonine is an essential amino acid with extensive applications in medicine, food, feed, and cosmetics. Currently, microbial fermentation stands as the predominant method for L-threonine production, with Escherichia coli serving as a crucial host strain due to its well-defined genetic background and metabolic regulation mechanisms, and ease of genetic manipulation. However, existing engineered strains still face challenges in industrial applications, including low production efficiency, osmotic pressure imbalance, acid-base metabolic disorders, and phage contamination. Therefore, the latest progress in constructing high-yield Escherichia coli strains that produce L-threonine using synthetic biology strategies was systematically reviewed, focusing on key techniques such as metabolic network reconstruction, gene expression regulation, and substrate utilization optimization. The challenges and future directions in industrial applications were also explored, aiming to provide theoretical guidance and technical references for the biomanufacturing of L-threonine and other aspartic acid family amino acids.

Dissimilatory iron-reducing bacteria (DIRB) mediated biologically induced mineralization (BIM) is a pivotal process that drives the geochemical cycling of iron. It involves microbial extracellular electron transfer (EET) to reduce Fe(III) oxides into Fe(II), resulting in the formation of secondary minerals, such as magnetite and vivianite. These secondary minerals hold significant potential for pollution control and remediation. This review elaborates on DIRB-driven mineralization mechanisms, outlines molecular-level electron transfer at microbe-mineral interfaces, and delves into environmental factors that influence biomineralization, such as anaerobic-aerobic interfaces and ionizing radiation. These analyses reveal the complex relationships between environmental conditions and mineralization processes. Furthermore, we summarize advances in environmental applications of DIRB-mediated mineralization, including heavy metal remediation, wastewater resource recovery, carbon sequestration, and the green synthesis of nanomaterials. Finally, future research on the environmental applications of dissimilatory iron reduction should aim to improve our understanding of biomineralization mechanisms in the presence of co-contaminants. Furthermore, it is crucial to validate these natural mineralization processes and verify their feasibility in engineered systems.

Nanomaterials are widely used in the fields of energy, environment protection, and biomedicine due to their excellent properties. Strategies using high temperatures, high pressures, and organic solvents in nanomaterial synthesis presents challenges, including potential environmental pollution and poor biocompatibility. Nanomaterial synthesis technology is undergoing a paradigm shift from traditional high-energy consumption processes to environmentally friendly ones. In this transformation process, green synthesis methods based on microorganisms have attracted widespread attention due to their significant ecological and economic benefits. Microbe-mediated green synthesis technology utilizes microorganisms including bacteria, fungi and microalgae to prepare nanomaterials, such as metals and metal oxides, through reduction, precipitation and templating. In the field of energy, nanomaterials synthesized by microorganisms are widely used in green energy technologies, such as photoelectric conversion, catalytic reactions, and electrochemical energy storage, due to their excellent catalytic activity and electron transfer properties. In the field of environmental protection, they are primarily used in pollution control processes, such as reducing heavy metals and degrading organic pollutants. Moreover, the microbe-nanomaterial hybrid system overcomes the limitations of the conventional “synthesis-separation-application” model. It achieves this by integrating microbial activity with the physicochemical properties of nanomaterials, thereby optimizing green energy utilization and environmental remediation. Future research should focus on elucidating the mechanisms of microbe-mediated nanomaterial synthesis, optimizing the performance of nanomaterials and scalable preparation, and broadening the multi-scenario applications to provide innovative solutions for sustainable energy utilization and environmental remediation.

Chimeric antigen receptor T (CAR-T) cell therapy involves genetically modifying T cells so that they can target and kill abnormal cells. It has achieved remarkable success in treating hematologic malignancies, marking a significant milestone in the development of tumor immunotherapy. It is also emerging rapidly as a hotspot in the biopharmaceutical sector. A bibliometric analysis of scientific literature reveals that basic research on CAR-T therapy on a global scale remains highly active, with the United States and China leading the field. An analysis of knowledge mapping using VOSviewer shows that China has established close collaborative networks with the United States, Germany, and the United Kingdom, among other countries, in basic research on CAR-T therapy. Current research hotspots focus primarily on four key areas: core technologies and basic research, efficacy improvement, clinical applications in oncology, and emerging applications in non-oncological fields. Future research in this field will concentrate on technological innovation, personalized medicine, and international collaboration.