Brazilian Journal of Microbiology最新文献

{"title":"Structural elucidation, antimicrobial activity, and cytotoxic potential of 6-methyl-1,3,8-trihydroxyanthraquinone and 1,8-dihydroxy-3-methylanthracenedione-9,10-dione compounds from mangrove derived rare actinobacterium Pseudonocardia parietis VLCH-6.","authors":"Chiranjeevi Chetapalli, Nagaraju Kumbha, Mary Swapna Mogili, Vijayalakshmi Muvva, Vengateshwaran Thasu Dinakaran","doi":"10.1007/s42770-026-02072-x","DOIUrl":"10.1007/s42770-026-02072-x","url":null,"abstract":"<p><p>Actinobacteria of mangrove habitats are the potential source of natural products. The work has been undertaken to optimize cultural conditions and elucidate the bioactive compounds produced by a mangrove derived potent rare actinobacterium. Pseudonocardia parietis VLCH-6 was proved as the potent actinobacterium strain, which was derived from the Machilipatnam mangrove habitats of Andhra Pradesh. This identification was based on polyphasic taxonomy, which included morphological, cultural, physiological, biochemical, and molecular approaches. During optimization process, ISP-2 (YMD) broth was recorded as suitable culture medium for enhanced metabolites yield. For maximum yield of the bioactive metabolites, glucose (2%) as carbon source and tryptone (1%) as nitrogen source were noticed. Further, after incubating the strain at 35⁰C for seven days, the optimum yield was observed when it was grown in a modified YMD culture medium that had been amended with NaCl (3%) and K₂HPO₄ (0.05%) to achieve a pH of 7. High antagonistic activity was demonstrated by the metabolites extracted from the optimized culture broth against a diverse array of pathogens. The isolation of two compounds with potential antimicrobial activity was achieved through column chromatography purification. The structures of bioactive compounds were elucidated through spectroscopic analysis including EIMS, FTIR, ¹H NMR and ¹³C NMR spectra. The two bioactive compounds were characterized as 6-methyl-1,3,8-trihydroxyanthraquinone and 1,8-dihydroxy-3-methylanthracenedione-9,10-dione. These compounds exhibited potential antimicrobial (MIC), anticancer activities against MCF-7 human breast cancer cell line and HEK293 human embryonic kidney cell line. This is the first publication on the characterization of bioactive chemicals produced by Pseudonocardia parietis VLCH-6.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13569816/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional action of Bacillus subtilis for Fusarium verticillioides biocontrol and growth promotion in corn seeds.","authors":"Melissa Tiemi Hirozawa, Mario Augusto Ono, Igor Massahiro de Souza Suguiura, Amanda Kaori Sugahara, Maria Inês Rezende, André Luiz Martinez de Oliveira, Elisabete Yurie Sataque Ono","doi":"10.1007/s42770-026-02080-x","DOIUrl":"10.1007/s42770-026-02080-x","url":null,"abstract":"<p><p>This study aimed to evaluate the in vitro antifungal activity and corn seed protective effect of two Bacillus subtilis isolates in two formulations, against Fusarium verticillioides, along with their indole acetic acid, siderophore production, and phosphate solubilization ability. Antifungal activity of two Bacillus subtilis isolates (NT1 and NT2) was investigated against F. verticillioides 97L in solid media and on corn seeds. Both B. subtilis isolates showed antifungal activity through production of diffusible antifungal compounds and NT2 showed the highest radial growth inhibition (61.7%). The seed treatments with B. subtilis based formulations, powder (P) and suspension (S), reduced the disease severity index compared to the control (P < 0.05), therefore they were efficient in inhibiting F. verticillioides 97L growth in corn seed and had no negative effects on seed germination and vigor. Concerning the vigor test, treatments with B. subtilis NT1(P) and NT2 (P) demonstrated a significant (P < 0.05) increase in shoot length and biomass production in comparison to the untreated seeds, which can be related to the ability of these isolates to produce indole acetic acid and to solubilize phosphate. None of the isolates produced siderophores. The B. subtilis isolates (NT1 and NT2) are promising biocontrol agents for developing new multifunctional formulations intended for management of corn disease caused by F. verticillioides as an alternative to chemical fungicides. Despite the efficacy observed in the current study, further research is required to evaluate the shelf-life and stability of the powder and suspension formulations under various storage conditions.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13569791/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148944401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenotypic characterization of raw milk-associated Pseudomonas spp.: biofilm formation across different temperatures, antimicrobial resistance, and cytotoxicity.","authors":"Maryam Montaseri, Mahkameh Ganji, Mina Rahiminejad, Mohammad Hosein Bastani","doi":"10.1007/s42770-026-02089-2","DOIUrl":"10.1007/s42770-026-02089-2","url":null,"abstract":"<p><p>This study investigated biofilm formation, antimicrobial resistance, and in vitro cytotoxicity in 31 Pseudomonas isolates recovered from raw milk, and assessed relationships among these traits. Biofilm formation was evaluated at 7, 15, 25, 37, and 42 °C using Congo Red Agar (CRA) and Crystal Violet (CV) assays. Antimicrobial susceptibility was determined by disk diffusion method, and cytotoxicity on Caco-2 cells was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Associations were assessed using Spearman's rank correlation with Benjamini-Hochberg false discovery rate (FDR) correction. The highest frequency of CRA-positive phenotypes occurred at 25 °C (90.3%), while all isolates were classified as biofilm producers by CV at this temperature; biofilm formation was also widely observed at 7 and 15 °C. Some isolates provisionally assigned to P. veronii, P. brenneri, and P. fluorescens showed strong biofilm-associated phenotypes in both CRA and CV assays at low temperatures. Cytotoxicity ranged from 0.11% to 42.8%. Multidrug resistance was detected in 90.3% of isolates, with a mean multiple antibiotic resistance (MAR) index of 0.52. CRA phenotypes were negatively correlated with cytotoxicity at 15 and 25 °C (P < 0.05). No significant associations were found between cytotoxicity and MAR index, individual antibiotic susceptibility, or quantitative CV measurements (P > 0.05). Most nominal associations between biofilm formation and individual antibiotics did not remain significant. These findings highlight substantial phenotypic diversity among raw milk-associated Pseudomonas and the ability of many isolates to maintain biofilm-forming phenotypes under dairy-relevant temperatures.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13569726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellulolytic potential of bacteria isolated from Australian marsupial herbivores.","authors":"Kaniz Fatema, Md Mezbaul Bahar, Mallavarapu Megharaj","doi":"10.1007/s42770-026-02090-9","DOIUrl":"10.1007/s42770-026-02090-9","url":null,"abstract":"<p><p>Cellulose, the most abundant renewable biopolymer on Earth, represents a key resource for biofuel production but requires efficient enzymatic hydrolysis to overcome its structural resistance. In this study, cellulose-degrading bacteria were isolated from fecal samples of two Australian marsupial herbivores: the koala (Phascolarctos cinereus) and the common wombat (Vombatus ursinus). Ten bacterial isolates were screened for cellulolytic activity; four strains exhibited substantial hydrolysis zones on carboxymethyl cellulose (CMC) agar and demonstrated elevated activity in fermentation broth. 16 S rRNA gene sequencing identified three isolates as Streptomyces spp. (K1, KFK6, KFWH) and one as Enterobacter sp. (KFWI). Optimization of cellulase production was conducted by varying incubation periods (24-168 h), pH (3.5-8.5), temperatures (27-50 °C), additives (NaCl, CaCl₂, ZnSO₄, MgSO₄, SDS, EDTA, Tween 80, Triton X-100), carbon sources (glucose, fructose, lactose, sucrose, CMC), and nitrogen sources (yeast extract, ammonium chloride, peptone, urea). K1, KFK6 and KFWI showed maximum CMCase production at 37 °C, whereas KFWH showed maximum production at 40 °C. The optimal pH was 7.5 for K1 and KFWI, and 6.5 for KFK6 and KFWH. Maximum enzyme production occurred at 72 h for K1 and KFWI, 120 h for KFK6, and 96 h for KFWH. These marsupial-derived isolates represent promising candidates for future studies on lignocellulosic biomass hydrolysis and other biotechnological applications.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13562478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lactic acid bacteria, potentially probiotic, in whole-grain pet biscuits: survival and technological potential of millet-based formulations (Pennisetum glaucum).","authors":"Wendy Carla Dantas Rocha, Isabel Luísa Ribeiro de Abreu Teixeira, Maria Eduarda Costa Campos, Taynan Jonatha Neves Costa, Isabella Maciel Costa, Debora Cristina Sampaio de Assis, Felipe Machado Trombete, Washington Azevedo da Silva, Erika Ramos de Alvarenga, Fabiola de Oliveira Paes Leme, Verônica Ortiz Alvarenga, Bruna Maria Salotti de Souza","doi":"10.1007/s42770-026-02091-8","DOIUrl":"10.1007/s42770-026-02091-8","url":null,"abstract":"<p><p>The relationship between humans and pets has driven the development of functional foods. This study aimed to develop pet biscuits containing Lacticaseibacillus paracasei GV17 and Lactococcus lactis GV103 and to evaluate the effects of wheat flour, millet flour, and a combination of both on the stability of lactic acid bacteria (LAB), resistance to simulated gastrointestinal tract (GIT) conditions, technological characteristics, and viability during storage. Three formulations were prepared using wheat flour (WF), millet flour (MF), and a mixture of flours (WMF), in which the GV17 and GV103 strains, as well as their combined culture (GV17.103), were incorporated into the biscuit cavities. The type of flour significantly influenced the physicochemical and technological characteristics of the formulations. A higher luminosity value was observed in the WF formulation (76.31), while the WMF showed greater hardness (46.18 N), indicating greater resistance to breakage. The MF presented higher lipid (24.80%) and fiber (5.76%) contents, WMF higher moisture (12.49%), and WF higher carbohydrate (55.95%). All formulations recover LAB counts to values above 7.0 log CFU/mL at the end of simulated digestion. WF103, MF103, and MF17.103 stood out for their storage stability. These results demonstrate that the tested matrices are suitable for the development of pet biscuits containing potentially probiotic LAB strains.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13562461/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arbovirus co-circulation and epidemiological convergence in a changing climate: challenges for surveillance, diagnosis and public health preparedness.","authors":"Gian Marco Ludovici, Alba Iannotti, Colomba Russo, Francesco Gargallo di Castel Lentini, Manousos E Kambouris, Mostafa Mohammed Atiyah, Sijo Asokan, Andrea Malizia, Marta Giovanetti","doi":"10.1007/s42770-026-02083-8","DOIUrl":"10.1007/s42770-026-02083-8","url":null,"abstract":"<p><p>Arboviral diseases are undergoing substantial epidemiological changes driven by climate change, urbanization, global mobility, vector expansion, and evolving ecological conditions. These processes increasingly favor the geographic overlap and co-circulation of multiple arboviruses, including in regions previously considered at limited risk. In this review, we describe this broader process as epidemiological convergence, referring to the progressive overlap of arboviral transmission systems across shared geographic, ecological, vector, host, and public health contexts. Such convergence creates interconnected challenges for clinical recognition, laboratory diagnosis, surveillance, and outbreak response. Diagnostic uncertainty is further amplified by overlapping clinical presentations, serological cross-reactivity, previous arboviral exposure, and co-infections or sequential infections. At the same time, pathogen-specific surveillance systems may inadequately capture increasingly complex transmission patterns, highlighting the need for integrated and interoperable approaches. One Health provides an essential framework for integrating human, animal, vector, and environmental dimensions of arboviral transmission. Complementarily, selected principles derived from Chemical, Biological, Radiological, Nuclear, and Explosive (CBRNE) preparedness may strengthen operational coordination, contingency planning, biosafety, risk communication, and response capacity during complex arboviral scenarios. However, their added value in arboviral settings requires further empirical evaluation. Addressing epidemiological convergence will ultimately require adaptable systems linking epidemiological understanding, diagnostic capacity, integrated surveillance, and operational preparedness.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13558541/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Encapsulation of probiotic Lactiplantibacillus plantarum S18 in sodium alginate: process optimization using Box-Behnken design for poultry feed application.","authors":"Wissam Hafir, Samia Hamma-Faradji, Zahra Azzouz, Abdellah Zikiou, Imen Trabelsi, Naourez Ktari, Riadh Ben Salah, Farida Bendali","doi":"10.1007/s42770-026-02059-8","DOIUrl":"10.1007/s42770-026-02059-8","url":null,"abstract":"<p><p>This study aimed to develop an effective method for encapsulating lactic acid bacteria (LAB) to improve their low survival rate under harsh environmental conditions. The strains were submitted to a battery of standard tests and criteria commonly used for determining their probiotic properties and attributes. A total of 22 LAB strains were isolated; the isolates were mostly resistant to ciprofloxacin, vancomycin and sulphamethoxazole/trimethoprim (clear zones = 0 mm), whereas S18 and S21 were sensitive and S19, S20 and S22 showed intermediate susceptibility (clear zones between 16 and 20 mm). They also demonstrated high tolerance to simulated gastro-intestinal tract conditions, maintaining viability in Man, Rogosa, and Sharpe (MRS) broth at gastric pH 2.5 and in the presence of 0.3% bile salts. In biofilm formation essays, 12 isolates showed strong adhesion to polystyrene microplates, and all selected strains exhibited significant inhibitory activity against tested pathogens. The strain displaying the best promising probiotic characteristics was identified through 16 S rRNA sequencing as Lactiplantibacillus plantarum S18. Encapsulation of this strain in sodium alginate was optimized using a box-benken design. The highest encapsulation efficiency (99.99%) was achieved using a bacterial cell concentration of 10⁸ CFU/ml, calcium chloride concentration of 1.540 M, a solidification time of 12 min, and a sodium alginate concentration of 2.15%. Overall, the findings demonstrate that sodium alginate-based encapsulation effectively preserves the stability and viability of Lactiplantibacillus plantarum S18, supporting its potential use as a probiotic additive in poultry feed.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13558532/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biotechnological valorization of rice waste from Trichoderma production through the development of a streptomyces-based biological soil conditioner.","authors":"Natacha Melo, Mateus Torres Nazari, Vera Analise Schommer, Valdecir Ferrari, Carlos Alberto Mendes Moraes, Regina Célia Espinosa Modolo, Fernando Joel Scariot, Ana Paula Longaray Delamare, Feliciane Andrade Brehm","doi":"10.1007/s42770-026-02039-y","DOIUrl":"10.1007/s42770-026-02039-y","url":null,"abstract":"<p><p>Sustainable soil management is vital for maintaining agricultural productivity while mitigating the environmental impacts of intensive pesticide use. This study evaluated the use of rice waste generated during Trichoderma asperelloides production as a substrate for the cultivation of Streptomyces sp. BEI-18 A through solid-state fermentation to obtain a biological soil conditioner. The rice waste from Trichoderma production (RWTP) underwent solid-state fermentation (SSF) for seven days, and the product was characterized according to the Brazilian Normative Instruction No. 35/2006 for soil conditioners and amendments. Biological analyses included colony-forming unit (CFU) counts, enzymatic activity (β-glucosidase and arylsulfatase), and respirometry. The conditioner was also applied to soil at different rates in maize (Zea mays L.) pot experiments to assess its effects on soil biological parameters. The application of the biological soil conditioner increased microbial abundance, enzymatic activity, and CO₂ release compared to the control, increasing β-glucosidase classification from moderate to adequate. Although physicochemical parameters did not meet the criteria for physical or chemical classification, the material met the requirements for classification as a biological soil conditioner. The results indicate that rice waste from T. asperelloides production can be reused as a substrate for producing bioinputs capable of enhancing soil biological activity.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13558514/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global expression profile of enterohemorrhagic Escherichia coli O157:H7 in phagosome of murine macrophages.","authors":"Nahuel Agustín Riviere, Lin Jiang, Xiuju Wu, Pablo Farace, Lu Guo, Libia Yael Smith, Wanderson Marques Da Silva, Ángel Adrián Cataldi, Ke Xing, Jinlong Bei, Mariano Larzábal","doi":"10.1007/s42770-026-02048-x","DOIUrl":"10.1007/s42770-026-02048-x","url":null,"abstract":"<p><p>Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes foodborne outbreaks leading to hemolytic uremic syndrome (HUS) via Shiga toxin (Stx). During HUS pathogenesis, EHEC O157:H7 is phagocytized by intestinal macrophages, although only a small proportion of internalized bacteria survive within the phagosome. To investigate this persistence, we performed global RNA-seq analysis of intracellular EHEC O157:H7 within murine macrophage phagosomes, complemented by in vitro assays simulating key phagosomal stressors. Our results reveal that EHEC employs a sophisticated survival strategy characterized by metabolic reprogramming and stress resistance. Inside macrophages, EHEC activates the SOS pathway, synthesizes membrane lipids, and engages NO detoxification mechanisms while repressing energetically costly virulence systems -motility, Type 3 Secretion System (T3SS), and Type 6 Secretion System (T6SS)-to prioritize survival. Notably, Shiga toxin gene regulation proved highly context-dependent: phagocytosis selectively upregulated the stx2a A subunit via the SOS response, whereas stx1a remained uninduced, likely restrained by NO-mediated repression. In contrast, under in vitro multi-stress conditions (pH 4.5) engaged the AR2-AR5 acid resistance systems and triggered robust expression of both stx1a subunits (A and B). These findings highlight the dynamic, stress-specific regulatory networks EHEC relies on to persist within the host.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13553990/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148910559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Turnover of microbial specialists and generalists shapes deterministic assembly and network stability along a salinity-alkalinity gradient in inland wetland soils.","authors":"Jie Wei, Fan Chang, Haomin Yang, Yan Sun, Zhi Li, Jun Li, Nannan Liu, Zhuan Hao","doi":"10.1007/s42770-026-02073-w","DOIUrl":"10.1007/s42770-026-02073-w","url":null,"abstract":"<p><p>Salinity-alkalinity gradients impose strong environmental filtering on soil microbial communities, yet the respective roles of generalist and specialist taxa in community assembly and stability remain insufficiently understood in wetland ecosystems. Here, bacterial and fungal communities were investigated across low, moderate, and high saline-alkaline zones in the Luyang Lake wetland, China. Amplicon sequencing was integrated with niche breadth analysis, community assembly inference, co-occurrence network analysis, cohesion metrics, and partial least squares path modeling to assess how generalists and specialists responded to environmental variation and contributed to microbial stability. Bacteria contained a larger generalist pool, whereas fungi were relatively enriched in specialists. Generalists were positively associated with nutrient availability and negatively associated with saline-alkaline stress, while bacterial specialists showed the opposite trend. Niche breadth decreased with increasing salinity-alkalinity, especially in bacteria, and this narrowing was accompanied by stronger deterministic assembly, mainly homogeneous selection. Network analysis further suggested that generalists contributed more to overall community connectivity, whereas specialists became more important for network organization under stronger saline-alkaline stress. Path modeling indicated that bacterial and fungal community stability was associated with distinct response pathways. Overall, salinity-alkalinity reorganized microbial communities by reducing niche breadth, strengthening deterministic assembly, and shifting the relative contributions of generalists and specialists to community stability. These findings improve our understanding of how niche strategy mediates microbial assembly and stability in saline-alkaline wetland soils.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13550284/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148905148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}