Archives of Microbiology最新文献

{"title":"Role of bacterial outer membrane vesicles in immune evasion during infection","authors":"Boshan Yan,&nbsp;Shiqi Chen,&nbsp;Jinjing Wan,&nbsp;Xinyuan Huang,&nbsp;Zhe Jia,&nbsp;Changlin Zhou,&nbsp;Lingman Ma","doi":"10.1007/s00203-026-05179-9","DOIUrl":"10.1007/s00203-026-05179-9","url":null,"abstract":"<div><p>Bacterial infections remain a major global public health challenge and are further exacerbated by the increasing prevalence of antimicrobial resistance. Furthermore, bacterial pathogens employ diverse strategies to escape host immune surveillance and establish persistent infections. In recent years, bacterial outer membrane vesicles (OMVs) have attracted considerable attention because of their important roles in host–pathogen interactions. Emerging evidence suggests that OMVs participate in bacterial immune evasion through multiple mechanisms. However, the complex mechanisms underlying OMVs-mediated modulation of host immunity remain incompletely understood. Here, we comprehensively review the current understanding of OMVs and the mechanisms contributing to bacterial immune evasion. Particular emphasis is placed on their roles in silencing host immune genes, regulating survival signaling pathways, promoting bacterial intracellular colonization, facilitating biofilm formation, modulating host inflammation and immune tolerance, neutralizing host immune effectors, and inducing epigenetic reprogramming. In addition, we discuss current and emerging strategies targeting OMV-mediated immune evasion. This review summarizes recent findings and provides insights into potential directions for future anti-infective research and therapeutic development.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148975450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant-derived and microbial biostimulants in sustainable agriculture: mechanisms, applications, and challenges","authors":"Pravej Alam,&nbsp;Sumera Nazneen,&nbsp;Bibi Hafsa Azra,&nbsp;Thamer Albalawi,&nbsp;Shamweel Ahmad,&nbsp;Mohammad Faizan","doi":"10.1007/s00203-026-05200-1","DOIUrl":"10.1007/s00203-026-05200-1","url":null,"abstract":"<div><p>Plant biostimulants have emerged as transformative and sustainable tools for improving crop productivity, resource-use efficiency, and resilience under rapidly intensifying environmental stresses. Unlike conventional agrochemicals, biostimulants function by activating physiological, biochemical, and molecular processes that optimize plant performance without directly supplying nutrients or exerting pesticidal effects. This review comprehensively examines the integrated roles of plant-derived and microbial biostimulants in sustainable agriculture, with particular emphasis on microbial-mediated mechanisms underlying plant stress adaptation and rhizosphere functioning. Plant-derived biostimulants, including seaweed extracts, humic substances, protein hydrolysates, amino acids, and chitosan, enhance nutrient acquisition, root architecture, hormonal regulation, and antioxidant defense systems. More importantly, microbial biostimulants, such as plant growth-promoting rhizobacteria (PGPR), endophytic microorganisms, mycorrhizal fungi, actinomycetes, yeasts, and cyanobacteria, exert multifunctional effects through biological nitrogen fixation, mineral solubilization, phytohormone biosynthesis, volatile signaling, osmolyte accumulation, pathogen suppression, and modulation of stress-responsive genes. These beneficial microorganisms reshape rhizosphere microbial communities, improve nutrient cycling, and enhance plant tolerance to drought, salinity, heat, and heavy metal toxicity. Emerging evidence from genomics, transcriptomics, metabolomics, and microbiome-based investigations has further revealed the molecular networks and signaling pathways governing biostimulant-induced resilience and plant–microbe interactions. Despite their substantial promise, inconsistent field performance, formulation instability, regulatory limitations, and inadequate mechanistic understanding continue to restrict their large-scale adoption. This review highlights recent advances in microbial and plant-derived biostimulants while identifying critical knowledge gaps and future opportunities for precision biostimulant engineering, microbiome manipulation, and climate-resilient crop management. The integration of next generation biostimulant technologies into sustainable agricultural systems may significantly reduce dependence on agrochemicals while improving crop productivity, environmental sustainability, and global food security.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148975312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a monoclonal antibody recognizing a conserved linear neutralizing epitope of pseudorabies virus gB protein","authors":"Yumei Chen,&nbsp;Jie Gao,&nbsp;RuiRui Liu,&nbsp;Yunchao Liu,&nbsp;Jingming Zhou,&nbsp;Hongliang Liu,&nbsp;Ying Li,&nbsp;Yanhua Qi,&nbsp;Chao Liang,&nbsp;Enping Liu,&nbsp;Sixuan Wu,&nbsp;Aiping Wang","doi":"10.1007/s00203-026-05094-z","DOIUrl":"10.1007/s00203-026-05094-z","url":null,"abstract":"<div><p>Pseudorabies virus (PRV), an α-herpesvirus, infects a variety of mammals. It is mainly prevalent in domestic pigs but can also infect humans, posing significant public health risks. The glycoprotein B (gB), a crucial structural protein involved in viral entry and immune recognition, is a key target for neutralizing antibodies of PRV. This study expressed gB glycoprotein to immunise mice using eukaryotic and prokaryotic systems. The hybridoma cell line secreting anti-gB antibodies was analysed, and the neutralising epitope targeted by this monoclonal antibody was identified. Six anti-PRV monoclonal antibodies were generated via the cell fusion technique. The characterization of mAbs revealed that 4A10 exhibited an IFA titer of 1:3200 and neutralization titer of 1:2⁴ with an antibody affinity of 3.4 × 10⁸ L/mol. The extracellular region of gB was divided into seven segments. The reaction of seven truncated proteins with six mAbs was identified by ELISA, with gB6 identified as the immunodominant epitope. Further truncation revealed that the peptide ⁶¹⁵RVPGERGTC⁶²³ was identified by 4A10 and as a B-cell linear epitope, which was localized within the loop domains of the gB carboxy-terminal (C-Terminal). Homology modeling and molecular docking technology revealed that 4A10 binds to ⁶¹⁵RVPGERGTC⁶²³ through its heavy chain CDR3 variable region. Antigenic epitope mapping revealed that epitope ⁶¹⁵RVPGERGTC⁶²³ is highly conserved among different PRV strains. This study identifies a highly conserved linear neutralizing epitope on PRV gB, providing a molecular basis for improving PRV diagnostic methods and optimizing prevention and control strategies. Pseudorabies virus (PRV) causes substantial economic losses in the swine industry worldwide. Glycoprotein B (gB) is a major target for neutralizing antibodies and vaccine design. In this study, we prepared a neutralizing monoclonal antibody (mAb) against PRV gB and identified its key linear neutralizing epitope. The epitope is highly conserved among prevalent PRV strains, highlighting its critical role in viral antigenicity. This work clarifies the molecular basis of PRV neutralization and identifies a conserved epitope, which upon further validation could serve as a diagnostic candidate and inform antiviral research.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation, identification and biological evaluation of endophytic fungi from Andrographis paniculata with special reference to antioxidant, antimicrobial and anticancer activities","authors":"Aditi Gupta,&nbsp;Kamlesh Kumar Shukla,&nbsp;Vineet Meshram","doi":"10.1007/s00203-026-05185-x","DOIUrl":"10.1007/s00203-026-05185-x","url":null,"abstract":"<div><p><i>Andrographis paniculata</i> is an important medicinal plant containing diverse bioactive constituents and is also a potential host for endophytic fungi capable of producing pharmacologically relevant secondary metabolites. The present study aimed to isolate and characterize endophytic fungi associated with the leaves of <i>A. paniculata</i> and to evaluate their phytochemical composition, antioxidant, antimicrobial, and anticancer potential. Thirteen endophytic fungal isolates belonging to the genera Colletotrichum, Acremonium, and Fusarium were isolated and characterized using morphological and molecular approaches. Four fractions were selected for testing of anticancer activity among thirteen isolates. Fungal metabolites were extracted using methanol, chloroform, and ethyl acetate and subjected to qualitative and quantitative phytochemical analysis. Antioxidant activity was evaluated using DPPH and FRAP assays, while antimicrobial activity was assessed against selected bacterial and fungal pathogens. Selected fungal fractions were further evaluated for cytotoxic activity against HeLa cells using the MTT assay. GC-MS analysis was performed on selected biologically active fractions for preliminary characterization of their chemical constituents. Among the tested fractions, the methanolic fraction of Colletotrichum sp. AD-12 exhibited the highest DPPH radical-scavenging activity (60.77 ± 4.71%), whereas the ethyl acetate fraction of Colletotrichum sp. AD-06 demonstrated the highest cytotoxic activity against HeLa cells (44.20 ± 5.05% inhibition). GC-MS analysis revealed chemically diverse constituents belonging to several compound classes, including alkanes, phenolic compounds, aromatic hydrocarbons, fatty-acid derivatives, and other metabolites. The findings indicate that <i>A. paniculata</i>-associated endophytic fungi possess diverse preliminary biological and chemical potential. Further studies involving compound purification, MIC/MBC determination, concentration-dependent cytotoxicity and IC₅₀ estimation, and mechanistic validation are required to establish the therapeutic significance of the identified metabolites.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Halosimplex yunnanense sp. nov., a novel haloarchaeon from an underground salt mine","authors":"Ming Gong,&nbsp;Aodi Zhang,&nbsp;Kexin Huang,&nbsp;Shilong Shao,&nbsp;Jinqiang Ma,&nbsp;Yue Ding,&nbsp;Shaoxing Chen","doi":"10.1007/s00203-026-05180-2","DOIUrl":"10.1007/s00203-026-05180-2","url":null,"abstract":"<div><p>Strain J119^T, a halophilic archaeon, was isolated from a salt mine sample collected in Yunnan Province, China. Cells are spherical (diameter 0.5–0.7 µm) or short‑rod‑shaped (0.4–0.5 × 0.7–0.8 µm), non‑motile, Gram‑stain‑negative, and can grow at 20–55°C (optimum 42°C), with NaCl tolerance ranging from 15% to 30% (w/v) (optimum 20%) and a pH growth range of 5.5–9.0 (optimum pH 7.0). Strain J119^T’s nearly complete 16S rRNA gene sequence (1,452 bp; accession MW736888.1) shows the highest sequence similarity (97.32%) to <i>Halosimplex salinum</i> YPL4^T; this value is lower than the species boundary threshold of 98.65%. Its <i>rpoB’</i> gene (1,830 bp; NZ_JBTJEL000000000.1) shares the highest similarity (95.52%) with <i>Halosimplex aquaticum</i> XZYJT29^T. Genomic analyses revealed that the average amino acid identity, average nucleotide identity and digital DNA–DNA hybridization values between strain J119^T and strains YPL4^T and XZYJT29^T were 78.58%, 82.59%, 25.50% and 82.61%, 85.70%, 29.20%, respectively. The genomic DNA G + C content of strain J119^T is 66.5%. Phenotypic, phylogenetic, and genome-based analyses suggest that strain J119^T (= KCTC 4326^T = MCCC 4K00178^T) represents a novel species of the genus <i>Halosimplex</i>, for which the name <i>Halosimplex yunnanense</i> sp. nov. is proposed.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and theoretical investigation of the antimicrobial effect of femtosecond laser irradiation on contact lens solutions","authors":"Mahmoud AbouGamea,&nbsp;Ahmed O. El-Gendy,&nbsp;Esraa Ahmed,&nbsp;Tarek Mohamed,&nbsp;Mohamed Mobarak","doi":"10.1007/s00203-026-05163-3","DOIUrl":"10.1007/s00203-026-05163-3","url":null,"abstract":"<div><p>Microbial contamination of contact lens solutions (CLS) can lead to eye infections, and traditional disinfectants often fail to eliminate resistant pathogens, underscoring the need for new disinfectants. We have studied the antimicrobial effects of femtosecond laser (FSL) irradiation and the combined effect of FSL irradiation and contact lens solutions (OPTI-FREE EXPRESS and CLIWEL) against common eye pathogens, methicillin-resistant <i>Staphylococcus aureus</i> (MRSA). The INSPIRE HF100 laser system emits FSL generated by a mode-locked Ti: sapphire femtosecond MAI TAI HP for laser exposure (400 nm, 50 mW, 15 min). The results demonstrated that each bacterial colony count was significantly reduced by FSL irradiation. The CLIWEL solution exhibited slightly higher antimicrobial activity compared to OPTI-FREE EXPRESS solution. Moreover, more inhibitory activity was demonstrated by the CLIWEL solution than that of the OPTI-FREE EXPRESS solution after FSL-exposed pathogens after 2 h. Therefore, the treatment with FSL irradiation and solution was more highly antimicrobial than FSL alone. The nonlinear theoretical logistic and Gompertz models have been applied to experimental data to interpret microbial behavior. The combination of FSL irradiation and lens solutions is a promising disinfection method that can improve the hygiene of the eye, reduce infection, and enhance ocular safety.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liana species and fertilization shape rhizosphere bacterial communities in abandoned iron mines","authors":"Jianting Ouyang,&nbsp;Mingyu Xu,&nbsp;Beiling Sun,&nbsp;Mianyi Huang,&nbsp;Acong Chen","doi":"10.1007/s00203-026-05192-y","DOIUrl":"10.1007/s00203-026-05192-y","url":null,"abstract":"<div><p>Climbing plants, with their vigorous root systems, strong adaptability, large biomass, and wide range of uses, hold great potential in mine soil restoration. To explore the ecological restoration effects of different liana species, the Longtie mining area in Longmen County, Huizhou City, Guangdong Province, China, was selected as the study site. Six liana species—<i>Canavalia gladiata</i>, <i>Benincasa hispida</i>, <i>Pueraria montana</i>, <i>Mucuna pruriens</i>, <i>Ipomoea quamoclit</i>, and <i>Ormosia semicastrata</i> were subjected to two treatments: fertilization and non-fertilization. The soil microbial diversity and community structure of the two treatments were analyzed using 16 S rRNA gene sequencing. The results showed that fertilization altered the diversity, composition, and structure of the microbial community. In terms of microbial diversity, the fertilized treatment had 1179 more bacterial ASVs (Amplicon Sequence Variants) than the non-fertilized treatment. After fertilization, Pueraria montana showed higher microbial abundance and diversity, with both Chao1 and ACE values exceeding 1200. In terms of microbial composition at the family level, the fertilized treatment had the highest relative abundance of <i>Gemmatimonadaceae</i> (18.01%), while the non-fertilized treatment had the highest relative abundance of <i>Nitrosomonadaceae</i> (15.93%). At the genus level, <i>Anaeromyxobacter</i> was the dominant genus, and <i>Ramlibacter</i> was the secondary dominant genus. Regarding the microbial community structure, distinct microbial communities were observed across different liana species, revealing pronounced heterogeneity and community differentiation.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced ethanol fermentation by thermotolerant Pichia kudriavzevii LC671435 in the presence of major lignocellulosic inhibitors","authors":"Ifeanyi Amara Ndubuisi,&nbsp;Chukwuemeka Samson Ahamefule,&nbsp;Obianuju Obiajulu Nnabuife,&nbsp;Jerry Obeta Ugwuanyi,&nbsp;James Chukwuma Ogbonna","doi":"10.1007/s00203-026-05171-3","DOIUrl":"10.1007/s00203-026-05171-3","url":null,"abstract":"<div><p>Lignocellulosic biomass is a sustainable feedstock for bioethanol production, but its industrial utilization is hindered by fermentation inhibitors generated during biomass pretreatment, including furfural, acetic acid, and formic acid. Developing robust thermotolerant yeasts capable of maintaining high ethanol productivity under these inhibitory conditions is essential for economically viable bioprocesses. This study evaluated the growth, viability, and fermentative performance of the thermotolerant yeast <i>Pichia kudriavzevii</i> LC671435 in the presence of major lignocellulosic inhibitors at 42 °C. The strain exhibited remarkable tolerance, remaining viable at concentrations of up to 35 mM furfural, 100 mM acetic acid, and 50 mM formic acid. Under these conditions, ethanol production reached 40.4 g/L (79.2% theoretical yield) in the presence of 35 mM furfural, 41.2 g/L (80.8% theoretical yield) with 80 mM acetic acid, and 39.3 g/L (77.1% theoretical yield) with 50 mM formic acid. Ethanol productivity remained above 2.0 g/L/h during the first 16 h of fermentation across all inhibitor treatments. Although combined inhibitor cocktails reduced fermentation efficiency, the strain consistently maintained ethanol production and retained fermentative activity over four consecutive repeated-batch fermentations although ethanol production progressively declined. These findings demonstrate that <i>P. kudriavzevii</i> LC671435 combines thermotolerance with broad inhibitor tolerance, enabling efficient ethanol production under conditions relevant to lignocellulosic biorefineries. This unique multi-stress-tolerant feature of <i>P. kudriavzevii</i> LC671435 makes it a potential strain for second-generation bioethanol production as well as positions it as a suitable candidate for investigating the molecular basis underlying the robust stress tolerance.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nematicidal and plant growth-promoting potential of the cell-free culture supernatant of Bacillus megaterium in tomato under Meloidogyne incognita infection: an in vitro and in vivo study","authors":"Anchita Singh,&nbsp;Nitika Kapoor,&nbsp;Puja Ohri","doi":"10.1007/s00203-026-05189-7","DOIUrl":"10.1007/s00203-026-05189-7","url":null,"abstract":"<div><p>This study evaluated the nematicidal efficacy and plant growth-promoting potential of the cell-free bacterial culture supernatant (BCS) of <i>Bacillus megaterium</i> in mitigating <i>Meloidogyne incognita</i>-induced stress in <i>Solanum lycopersicum</i> under both in vitro and in vivo conditions. Mortality bioassay revealed that cell-free BCS induced a clear dose- and time-dependent nematicidal response, with maximum juvenile mortality of 100% observed at 100% concentration within 96 h (<i>p</i> &lt; 0.001). <i>B. megaterium</i> was characterized for plant growth-promoting and biocontrol traits including indole−3-acetic acid (IAA) synthesis, ammonia production, phosphate solubilization, hydrogen cyanide (HCN) production and protease activity. The experiments conducted on 10-day-old seedlings (in vitro<i>)</i> and 45-day-old plants (in vivo) revealed that nematode infestation impaired morphological attributes, reduced photosynthetic pigments and elevated stress indices. However, cell-free BCS treatment markedly reduced galling, enhanced growth parameters, lowered stress markers and modulated antioxidant responses along with increased levels of secondary metabolites. Confocal microscopy analyses revealed enhanced cell viability and increased glutathione accumulation in cell-free BCS treated seedlings. This study provides new insights into morphological, biochemical and physiological responses of <i>M. incognita</i>-stressed <i>S. lycopersicum</i> treated with cell-free BCS and highlights the potential of <i>B. megaterium</i> as a sustainable biocontrol and plant growth- promoting agent under controlled conditions.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and genomic characterization of Bacillus X32: a potent phosphate-solubilizing bacterium with growth-promoting effects on navel orange seedlings","authors":"Wenyuan Zhao,&nbsp;Tao Peng,&nbsp;Haojie Cao,&nbsp;Huimin Huang,&nbsp;Ming Chen,&nbsp;Shuijing Yu","doi":"10.1007/s00203-026-05173-1","DOIUrl":"10.1007/s00203-026-05173-1","url":null,"abstract":"<div><p>Phosphorus is an essential element for plant growth. However, in nature, most phosphorus exists in the form of insoluble compounds that plants cannot directly absorb, leading to phosphorus deficiency in agricultural systems. With increasing demand for economic crops such as citrus and the decline in soil fertility due to current management practices, there is a growing need for environmentally friendly fertilizers to improve and restore soil conditions. In this study, a highly efficient phosphate‑solubilizing strain X32 was isolated from the rhizosphere soil of Gannan navel oranges. Systematic genomic analysis identified it as a putative novel species within the genus Bacillus, showing the closest phylogenetic relationship to <i>Bacillus spizizenii</i>. However, both the average nucleotide identity (ANI = 93.18%) and digital DNA‑DNA hybridization (dDDH = 50.4%) values fell below the established thresholds for species delineation, indicating significant genomic differentiation. Whole‑genome sequencing further revealed that strain X32 harbors multiple functional genes potentially related to phosphorus metabolism, including inorganic phosphate‑solubilizing genes (e.g., <i>gdh</i> and <i>gltA</i>), phosphate transport genes (e.g., <i>glpT</i>, <i>pstA</i>, <i>pstB</i>, <i>pstC</i>), and phosphorus mineralization genes (e.g., <i>phoA</i>,<i> phoD</i>). Pot experiment results demonstrated that inoculation with strain X32 significantly promoted the growth of navel orange seedlings, as evidenced by marked increases in both aboveground and belowground fresh and dry weights, as well as plant height. Additionally, strain X32 significantly enhanced the activities of antioxidant enzymes (SOD, CAT, POD) and regulated the content of chlorophyll b in seedling leaves, these changes suggest that strain X32 may enhance stress resistance in plants and influence photosynthetic pigment composition, though direct measurements of photosynthetic performance are needed for confirmation. This study provides a theoretical basis for developing microbial fertilizers with efficient phosphorus solubilization and plant growth-promoting functions, which may help reduce dependence on phosphorus fertilizers and promote sustainable agricultural development.</p></div>","PeriodicalId":8279,"journal":{"name":"Archives of Microbiology","volume":"208 12","pages":""},"PeriodicalIF":3.4,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148918181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}