The continuous evolution and drug-resistant mutations of influenza virus have placed higher demands on the study of its pathogenic mechanism, as well as the development of antiviral drugs and vaccines. As a key tool for real-time monitoring of viral infection, replication and transmission, viral visualization reporter systems have evolved into various strategies, including high-resolution microscopic imaging, exogenous nanomaterial labeling, recombinant reporter viruses, and virus infection-inducible reporter systems. This manuscript systematically reviewed the research progress of influenza virus visualization technologies, elaborated the principles, core breakthroughs, and application scenarios of each technique, analyzed the common limitations and specific problems existing in the current technical system, and prospected its development direction combined with cutting-edge research, providing a reference for technical selection and innovative applications in influenza virus visualization research.

The increasing emission of sulfur-containing compounds has become a critical factor restricting ecological and environmental security and the sustainable resource utilization. Biological desulfurization technology, relying on the sulfur metabolic pathways of desulfurization microorganisms, enables the efficient conversion of sulfur-containing pollutants and the recovery of sulfur resources under mild conditions, offering both environmental benefits and economic potential. This review systematically summarized the classification and functional characteristics of desulfurization microorganisms, with emphasis on the 4S pathway, the Kodama pathway, and related metabolic modes of organic sulfur-desulfurizing bacteria, as well as the sulfate reduction and sulfur oxidation mechanisms of inorganic sulfur-desulfurizing bacteria. On this basis, the advances in engineering applications in the fields of industrial gas purification, sludge and wastewater treatment, livestock and poultry manure management, domestic waste and agriculture were summarized, and the key environmental factors and carbon source regulation mechanisms affecting desulfurization efficiency were analyzed. Furthermore, the main bottlenecks currently faced by biological desulfurization technology were summarized from the aspects of strain performance, reaction kinetics, mass transfer enhancement, and process stability, and research directions for system enhancement through functional microbial community construction, reactor optimization, and intelligent regulation were proposed. This review aims to provide theoretical references and technical insights for the deepening of biological desulfurization mechanisms and efficient engineering applications.

As a key group of the gut microbiota that helps maintain intestinal homeostasis, probiotics have attracted significant attention in life science and medical research. Akkermansia muciniphila (AKK), a strictly anaerobic Gram-negative bacterium, has swiftly become a central topic in gut microbiota research owing to its unique metabolic properties and considerable probiotic potential. This review systematically summarizes the discovery, physiological characteristics, and isolation methodologies and screening of AKK, while placing a particular emphasis on its role in preventing and managing a spectrum of human and animal diseases (including tumors, neurodegenerative disorders, metabolic syndromes, and inflammatory bowel diseases), thereby offering novel perspectives and potential targets for disease intervention. Furthermore, this review elucidates the core mechanisms underlying the probiotic functions of AKK. Specifically, AKK exerts beneficial effects on host health and therapeutic effects on diseases primarily through three key pathways: modulating intestinal microecological balance and barrier integrity, regulating systemic metabolic processes and immune responses, and mediating intricate crosstalk between the intestine and multiple extra-intestinal systems. To assess the translational efficiency of AKK, we summarize the current application status of its functional-related proteins and preparations in health, analyze clinical application scenarios and potential, and discuss existing bottlenecks and challenges in industrial application. This review provides a comprehensive theoretical reference and directional guidance for future basic research, application development, and industrialization of AKK.

Trichoderma reesei is recognized as the microorganism with the most potent protein secretion capability known to date. It is extensively utilized for cellulase production and has garnered significant attention in heterologous protein synthesis. Although notable progress has been achieved in the screening of expression elements, chassis engineering, and fermentation process optimization, critical challenges persist, and the large-scale industrial application of heterologous protein expression has not yet been fully realized. This paper reviews the strategies and recent research advances regarding the high-efficiency expression of heterologous proteins in T. reesei. Furthermore, this paper discusses the limiting factors for its industrial-scale application and proposes novel recommendations and strategies to enhance heterologous protein yields.

[Objective] To address the scarcity of neutral sites in Corynebacterium glutamicum ATCC 13032 caused by high G+C content and short intergenic sequences, we established a computer-aided screening platform to identify and characterize efficient neutral sites suitable for heterologous gene integration, aiming to provide key component support for constructing high-performance cell factories. [Methods] A computational screening platform CgNSFinder was constructed to screen candidate neutral sites by integrating heuristic rules such as genomic annotation, neighborhood characteristics, length, and G+C content. The candidate sites were systematically characterized in terms of integration efficiency, cell adaptability, expression intensity, and stability through reporter gene mKate knock-in experiments. We integrated the amylase gene, lycopene synthesis gene cluster, and key L-lysine synthesis genes into the screened sites to verify their heterologous expression ability and application efficiency. [Results] A total of 96 candidate neutral sites were screened out, from which 24 efficient sites were confirmed by experimental characterization. Among them, 19 sites had an integration efficiency greater than 50%, and 22 sites had a fluorescence expression intensity within the range of 2 400-3 500 a.u. The NS3 site showed the best performance, and the lycopene titer reached 48.4 mg/L after multi-copy integration. The L-lysine-producing strain D301 constructed based on the screened sites achieved a titer of 49.51 g/L, a yield of 14.25 g/g, and a productivity of 1.53 g/(L·h) in a 5-L fermenter. [Conclusion] The established neutral site screening method is efficient and feasible. The screened neutral sites are characterized by high integration efficiency, low host interference, and stable expression. This study provides an important tool for metabolic engineering of C. glutamicum.

[Objective] We investigated the characteristics of rhizosphere bacterial communities of healthy and root rot-infected strawberry plants across different plots, as well as their correlations with soil physicochemical properties, aiming to discover and isolate beneficial rhizosphere bacteria with significant inhibitory effects against strawberry root rot pathogens to support disease management. [Methods] We utilized high-throughput sequencing combined with bioinformatics analysis to elucidate the differential characteristics and influencing factors of rhizosphere bacterial communities between healthy and diseased strawberry plants. Then, we employed the dilution plate method and dual culture assay to isolate antagonistic bacteria. Subsequently, we determined the taxonomic status of these beneficial strains by combining morphological observation with multi-gene phylogenetic analysis. [Results] The bacterial community diversity varied across different cultivation bases. Compared with that of healthy plants, the rhizosphere soil samples of diseased strawberry plants from the Xinzhuang and Kangshou bases showed decreased bacterial InvSimpson, Chao1, and Shannon evenness indices (P>0.05). Conversely, the rhizosphere soil samples of diseased strawberry plants from the Taolin base showed increased InvSimpson and Shannon evenness indices (P<0.05). Beta diversity analysis revealed that root rot significantly altered the microbial community structure. The complexity and stability of the rhizosphere bacterial co-occurrence network decreased in the diseased samples. Redundancy analysis indicated that soil total organic carbon, available phosphorus, and total potassium were the primary physicochemical factors shaping the bacterial community structure in strawberry rhizosphere. We isolated two bacterial strains, N2-10 and N2-18, that exhibited significant antagonistic activity from the healthy strawberry rhizosphere. The two strains demonstrated inhibition rates ranging from 55.6% to 62.2% and 54.5% to 66.7%, respectively, against the tested strawberry root rot pathogens. We identified strains N2-10 and N2-18 as Bacillus cereus and Bacillus velezensis, respectively. [Conclusion] We clarify how root rot affects strawberry rhizosphere bacterial communities and identify two beneficial rhizosphere bacterial strains with strong biocontrol potential. These findings provide a theoretical basis and valuable strain resources for elucidating the mechanisms of strawberry root rot and developing microbial-based green control technologies.

[Objective] To elucidate the primary bioactive component in Psoralea corylifolia seed extract that is responsible for inhibiting Pseudomonas amygdali pv. lachrymans (Pal) and to characterize its antibacterial mechanism. [Methods] The effect of isopsoralen on the growth curve of Pal and its minimum inhibitory concentration (MIC) were determined by the liquid culture assay. The antibacterial mechanism was investigated by transmission electron microscopy (TEM) combined with physiological and biochemical analyses. [Results] The MIC of isopsoralen against Pal was 400 mg/L. Isopsoralen disrupted the integrity of the bacterial cell wall and cell membrane, leading to leakage of intracellular contents. It interfered with cellular energy metabolism by inhibiting the activity of respiratory chain dehydrogenases. In addition, it impaired bacterial responses to environmental changes and colonization in the host by suppressing swarming motility, swimming motility, and biofilm formation. [Conclusion] Isopsoralen exerts its inhibitory activity against Pal through the synergistic actions of structural damage, energy disruption, and virulence suppression, ultimately abolishing the pathogen’s ability to infect the host. These findings provide a theoretical basis for the application of P. corylifolia seed extract as a botanical bactericide in the green management of cucumber bacterial angular leaf spot.

[Objective] To investigate the effects of pea-oat mixed cropping at different ratios on soil nutrients, enzyme activities, and carbon-fixing microbial communities in the alpine region of Qinghai Province. [Methods] This study designed five treatments: monoculture of oat (T0), monoculture of pea (Q0), and pea-oat mixed cropping at three ratios (QT1, QT2, and QT3). Soil enzyme activities and physicochemical indicators were measured, and the community structure, diversity, and relationships with environmental factors of carbon-fixing bacteria were analyzed based on high-throughput sequencing data of cbbL. [Results] Compared with monoculture, mixed cropping significantly enhanced soil enzyme activities and nutrient content, with QT3 (the pea:oat ratio of 2:1) showing the most pronounced effects. Under QT3, the activities of sucrase, cellulase, protease, and other enzymes were the highest, and the content of soil organic carbon, total nitrogen, ammonium nitrogen, and other nutrients was also significantly increased. Mixed cropping optimized the community structure of soil carbon-fixing bacteria. Specifically, QT3 significantly increased the alpha diversity (with the highest Chao1 and Shannon indices) and enriched functional groups such as Cyanobacteria. Environmental factor analysis indicated that soil ammonium nitrogen, total nitrogen, and organic carbon were the main drivers of changes in the carbon-fixing bacterial community. Furthermore, microbial co-occurrence network analysis revealed that mixed cropping, especially QT3, significantly enhanced network complexity, connectivity, and modularity, which indicated higher structural stability and functional collaboration potential of the microbial community. [Conclusion] Pea-oat mixed cropping, particularly at a ratio of 2:1, significantly improved soil ecological functions in alpine regions by enhancing soil enzyme activities, increasing nutrient availability, and optimizing the structure and functional network of carbon-fixing microbial communities. This provides an effective approach for enhancing soil carbon sequestration potential and promoting sustainable agricultural development.

Ergosteryl-β-glucosidase (Egh1) catalyzes the hydrolysis of ergosteryl-β-glucoside for producing free ergosterol and glucose. This enzyme plays a crucial role in maintaining intracellular membrane lipid homeostasis and regulating the morphological stability of organelles, including vacuoles. However, the biological functions of this enzyme class in plant pathogenic fungi remain poorly understood. [Objective] To elucidate the role of MoEGH1, an Egh1 homolog in Magnaporthe oryzae, in appressorium development, sterol metabolism, autophagy regulation, and pathogenicity. [Methods] MoEGH1, homologous to yeast EGH1, was identified by sequence homology analysis. A deletion mutant ΔMoegh1 was constructed through targeted gene replacement. The biological functions of MoEgh1 were systematically examined through phenotypic characterization, genetic complementation, autophagic flux assays, and assessments of appressorium formation and turgor pressure. [Results] The deletion of MoEGH1 markedly impaired the growth, development, and pathogenicity of M. oryzae. ΔMoegh1 displayed significantly reduced radial growth and conidiation, an increased proportion of malformed conidia, a substantial decrease in appressorial turgor pressure, and defective appressorium formation. These developmental defects led to an almost complete loss of pathogenicity. Furthermore, compared with the wild‑type strain, ΔMoegh1 demonstrated heightened sensitivity to rapamycin and sterol‑targeting antifungal agents, including natamycin, amphotericin B, and itraconazole. Additionally, the mutant displayed abnormally elevated activity of the target of rapamycin (TOR) signaling pathway concomitant with reduced levels of autophagy. [Conclusion] MoEgh1 is essential for vegetative growth, conidiation, and appressorium formation in M. oryzae. MoEgh1 regulates the autophagy process and sterol homeostasis by modulating TOR activity, thereby playing a critical role in the pathogenicity of this fungus.

[Objective] To elucidate the role of arginine methyltransferase in the growth, development, and pathogenicity of Botrytis cinerea. [Methods] Bioinformatics approaches were used to perform sequence alignment, phylogenetic analysis, and conserved domain prediction of the arginine methyltransferase HMT2 from eight fungal species, including B. cinerea, Saccharomyces cerevisiae, Fusarium graminearum, and Magnaporthe oryzae. The gene encoding this enzyme in B. cinerea was identified as BcHMT2. The BcHMT2-deleted mutant was constructed via homologous recombination, followed by phenotypic characterization and pathogenicity assays. [Results] The BcHMT2-deleted mutant exhibited a significantly reduced growth rate, significantly weakend cell wall-degrading enzyme activity, and decreased sclerotial production and conidiation. Meanwhile, the hyphal cells became smaller and the conidial morphology was abnormal. In addition, the mutant displayed markedly attenuated pathogenicity on tomato fruits and tobacco leaves. [Conclusion] This study reveals the regulatory role of BcHMT2 in the growth, development, and pathogenicity of B. cinerea, providing novel insights into the research on the prevention and control of gray mold.