International Microbiology最新文献

{"title":"Copper homeostasis networks in pseudomonas aeruginosa and the organocopper metabolite fluopsin C.","authors":"Dongwon Choi, Tariqul Islam","doi":"10.1007/s10123-026-00837-w","DOIUrl":"https://doi.org/10.1007/s10123-026-00837-w","url":null,"abstract":"<p><p>Copper is an essential redox-active trace element that serves as a catalytic cofactor in many bacterial enzymes; however, excess intracellular copper is highly cytotoxic due to mismetallation of metalloproteins and copper-driven redox cycling that promotes reactive oxygen species generation through Fenton-like chemistry. To prevent these destructive effects, bacteria maintain near-zero levels of free cytosolic copper through tightly coordinated copper homeostasis networks. This review summarizes current understanding of bacterial copper stress physiology with a focus on the exceptionally copper-tolerant opportunistic pathogen Pseudomonas aeruginosa. This organism deploys a multilayered detoxification strategy that includes periplasmic copper surveillance and export mediated by the CopRS-PcoBA system, as well as highly sensitive cytoplasmic copper sensing that activates CueR-regulated efflux modules. A distinctive feature of the P. aeruginosa copper homeostasis network is the biosynthesis of the organometallic copper complex fluopsin C via a copper-responsive biosynthetic operon and its subsequent export through a dedicated efflux pump. This pathway supports a model in which fluopsin C functions as a copper-sequestering metabolite that stabilizes Cu(I), suppresses redox-mediated toxicity, and enables safe copper removal as a ligand-bound complex. Beyond its physiological role in copper detoxification, fluopsin C exhibits broad-spectrum antibacterial and antifungal activity and pronounced cytotoxicity toward mammalian tumor cell lines, consistent with a mechanism involving membrane disruption and ionophore-like copper shuttling. These properties suggest potential utility of fluopsin C as a metal-based, membrane-active antimicrobial in localized or formulation-controlled applications. Despite renewed interest in fluopsin C, optimization of its production remains limited, underscoring the need for future cultivation and bioprocess studies to improve yield and enable broader experimental and translational evaluation.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient cyanide degradation by Aspergillus welwitschiae LOT1 isolated from industrial waste.","authors":"Olusola T Lawal, Samuel T Osunpidan, David M Sanni","doi":"10.1007/s10123-026-00824-1","DOIUrl":"https://doi.org/10.1007/s10123-026-00824-1","url":null,"abstract":"<p><p>Cyanide is a potent cytotoxin and neurotoxin largely derived from anthropogenic activities and can accumulate in the environment through industrial wastewater, posing serious ecological and health risks. This study evaluated the cyanide degradation capacity of intact Aspergillus welwitschiae LOT1 biomass under varying physicochemical and nutritional conditions. Cyanide degradation refers to the biochemical breakdown of cyanide into simpler compounds, whereas detoxification describes the conversion of cyanide into less toxic metabolites. Cyanide removal by A. welwitschiae LOT1 was influenced by pH, temperature, substrate concentration, inoculum size, and co-metabolites, with optimal degradation occurring at pH 12 (~ 80% efficiency), 50 °C (~ 36%), and an initial cyanide concentration of 60 mM (~ 75%). Agricultural wastes, particularly corn stalk, enhanced degradation efficiency (~ 84%) compared with refined sugars, while the combination of 40 mM cyanide and 40 mM glucose produced approximately 85% degradation. HPLC analysis confirmed substantial cyanide removal and detected formamide, ammonia, and carbon dioxide as detoxification products, supporting an enzymatic transformation pathway. Although alkaline conditions may contribute to abiotic cyanide loss, enhanced removal in inoculated cultures suggests biological involvement. Future studies should focus on the molecular characterisation of degradation enzymes and on the evaluation of A. welwitschiae LOT1 in pilot-scale and field-based bioremediation systems.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the antifungal and antioxidant activity of Agaricus bisporus extract using gamma radiation: implications for shelf-life extension of fresh-cut apples.","authors":"Mohamed S Abd El-Al, Doaa A Emam, Eman Araby, Abeer A Khattab","doi":"10.1007/s10123-026-00806-3","DOIUrl":"https://doi.org/10.1007/s10123-026-00806-3","url":null,"abstract":"<p><p>Fresh-cut fruits are highly perishable due to enzymatic browning and microbial spoilage following tissue disruption. This study investigated whether γ-irradiation of the edible mushroom Agaricus bisporus enhances its antioxidant and antifungal properties and whether the treated extract can be applied as a natural preservative for fresh-cut apples. Ethanolic extracts of A. bisporus were irradiated at 0-8.0 kGy and evaluated against six apple-spoiling fungi (Penicillium expansum, P. chrysogenum, Botrytis cinerea, Fusarium oxysporum, Aspergillus flavus, and A. niger). Among the tested solvents, ethanol yielded the most potent extract, showing a 14-mm inhibition zone against P. chrysogenum. Irradiation at 6.0 kGy significantly increased total phenolic content (3.25 mg GAE g⁻¹) and DPPH scavenging activity (46.3% at 100 µg mL⁻¹) (p < 0.05). The 6.0 kGy extract inhibited fungal enzymes-protease (40%), cellulase (35%), and lipase (45%)-and caused hyphal deformation, as observed by SEM. Sorbitol protection assays indicated cell-wall targeting. GC-MS profiling revealed irradiation-induced modifications in the fatty acid and sterol compositions. When applied at 10% (w/v) to fresh-cut apples stored at 4 °C for 10 days, the irradiated extract reduced browning, retained firmness, and decreased fungal and bacterial counts by 1.3 and 1.6 log CFU g⁻¹, respectively. Overall, mild γ-irradiation (6.0 kGy) enhanced the bioactivity and preservative potential of A. bisporus extract, supporting its application as a natural, clean-label agent for fresh-cut produce preservation.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147815328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to: Nanoformulation of peppermint (Mentha Piperita L.) and rosemary (Rosmarinus officinalis L.) essential oils: antibacterial effects.","authors":"Sahar Teimouri, Mahmoud Pouryousef Miandoab, Leila Jabalameli, Shahram Aramideh, Azam Haddadi","doi":"10.1007/s10123-026-00823-2","DOIUrl":"https://doi.org/10.1007/s10123-026-00823-2","url":null,"abstract":"","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147815397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-guided antimicrobial potential of Bacillus stercoris from coastal sand with activity against multidrug-resistant bacteria, including MRSA.","authors":"Camilla Andrade Silva Valença, Bruno Andrade, Marcus Viana, Ana Andrea Teixeira Barbosa, Silvio Santana Dolabella, Patrícia Severino, Guillaume Ménard, Yoann Augagneur, Bertram Brenig, Eliana B Souto, Vasco Azevedo, Eric Guedon, Sona Jain","doi":"10.1007/s10123-026-00836-x","DOIUrl":"https://doi.org/10.1007/s10123-026-00836-x","url":null,"abstract":"<p><p>Coastal beach environments harbor diverse bacterial communities, yet their antimicrobial potential remains largely unexplored. This study evaluates the antimicrobial potential of a bacterial isolate 2AT10 from Brazilian beach sand through in vitro, in silico, and ex vivo assays. Isolate 2AT10, a rod-shaped Gram-positive bacterium, exhibited broad-spectrum antimicrobial activity, with its culture supernatants showing greater efficacy against Gram-positive bacteria, including multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial activity from two differently processed supernatants decreased after heat treatment, enzymatic digestion, and pH changes, suggesting similar proteolytic profiles. Fourier-transform infrared spectroscopy (FTIR) revealed peaks corresponding to C = O and NO₂ groups, indicating the presence of amide functional groups. Importantly, the supernatants did not cause irritation in the ex vivo chorioallantoic membrane assay. Genomic analysis identified isolate 2AT10 as Bacillus stercoris, harboring genes encoding subtilosin A, bacilysin, bacillibactin, bacillaene and lactococcin-like bacteriocins, all associated with antimicrobial activity. A mutation in the sboA gene, involved in subtilosin A biosynthesis and previously linked to in vitro hemolytic activity and enhanced activity against Gram-positive bacteria, was also detected. Molecular docking and dynamics analyses suggested a possible interaction between lactococcin-like bacteriocin and a membrane component of the S. aureus phosphotransferase system transporter, possibly increasing membrane permeability.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147815359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative pathogenomics and in silico analysis of energy metabolism in Acinetobacter baumannii ST195 and novel Turkish isolates encoding blaOXA-23, blaOXA-66, and blaOXA-852.","authors":"Marwah S H Al-Khalidi, Ahmet E Yetiman, Mikail Akbulut, Pınar Sağıroğlu","doi":"10.1007/s10123-026-00828-x","DOIUrl":"https://doi.org/10.1007/s10123-026-00828-x","url":null,"abstract":"","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green-synthesized metal oxide nanoparticles enhance the antibacterial activity of Portulaca oleracea through foliar nano-elicitation.","authors":"Ayesha Arif, Sadaf Anwaar, Nyla Jabeen, Tauseef Anwar, Huma Qureshi, Hossam S El-Beltagi, Ibtisam M Alsudays, Khalid H Alamer, Shavkat Durxadjayev, Nazih Y Rebouh, Khudiyev Orkhan, Shuqurillo Ziyadov, Mohammed S Alotaibi, Mohd Asif Shah","doi":"10.1007/s10123-026-00829-w","DOIUrl":"https://doi.org/10.1007/s10123-026-00829-w","url":null,"abstract":"<p><p>Acne-associated and other skin-related bacterial infections are increasingly difficult to manage because of antimicrobial resistance and the need for safer therapeutic alternatives. Portulaca oleracea is a medicinal plant with recognized bioactive potential, yet its antibacterial activity can potentially be enhanced through nano-elicitation. Unlike studies that examine nanoparticles as direct antimicrobials, this work investigated green-synthesized metal oxide nanoparticles as foliar elicitors to improve the antibacterial potential of P. oleracea extracts. This approach links sustainable nanoparticle synthesis with medicinal-plant priming to generate extracts with greater activity against acne-associated pathogens. Zinc oxide, magnesium oxide, and alpha-iron oxide nanoparticles were synthesized using aqueous Psidium guajava leaf extract and verified by standard physicochemical characterization. P. oleracea plants received foliar applications of 100 ppm nanoparticle suspensions under greenhouse conditions, after which methanolic aerial-part extracts were evaluated against Staphylococcus aureus, Escherichia coli, and Cutibacterium acnes. Iron oxide treatment produced the strongest response without visible phytotoxicity. By day 25, FeNP-treated plants reached 10.7 ± 0.7 cm in height and 12 ± 1 leaves, compared with 9.1 ± 0.6 cm and 10 ± 1 leaves in untreated controls. Extracts from FeNP-treated plants also showed the highest antibacterial activity, with inhibition zones of 20.0 ± 1.7 mm against S. aureus, 15.7 ± 1.5 mm against E. coli, and 18.3 ± 1.5 mm against C. acnes. These findings show that foliar nano-elicitation, particularly with FeNPs, can enhance plant growth and strengthen the antibacterial potential of P. oleracea. Because phytochemical changes were inferred indirectly from FTIR patterns and antibacterial response rather than direct metabolite quantification, future studies should perform quantitative phytochemical profiling and confirm extract potency through MIC and MBC assays.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Allium cepa mediated green synthesis of ZnO nanoparticles with antibacterial antibiofilm and synergistic activity against uropathogenic multidrug resistant Escherichia coli.","authors":"Saba Sana, Turki M Dawoud, Zoya Maheen, Qaiser Farid Khan, Shagufta Irshad, Sikander Ali, Layyaba Nazir, Tawaf Ali Shah, Rahman Shahzaib Saleem, Tousif Husain, Molalign Assefa","doi":"10.1007/s10123-026-00835-y","DOIUrl":"https://doi.org/10.1007/s10123-026-00835-y","url":null,"abstract":"","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 characterization of ureolytic bacteria driving microbially induced calcite precipitation in cement contaminated soil.","authors":"Daniel Mulu Mengistu, Daniel Girma Hordofa","doi":"10.1007/s10123-026-00833-0","DOIUrl":"https://doi.org/10.1007/s10123-026-00833-0","url":null,"abstract":"","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal trends in Group B Streptococcus colonization, serotype distribution, and antimicrobial resistance among pregnant women in the Brazilian Amazon across the COVID-19 pandemic, 2018-2023.","authors":"Anjo Gabriel Carvalho, Mayra Gyovana Leite Belém, Erilene de Lima Sinos, Marcos Eduardo Passos da Silva, Renata Santos Rodrigues, Izabelly Vitória Gotara Ramos, Gil Guibson Mota Amaral, Luccas Manoel de Melo Suica, Valcimar Ferreira Batista, Núcia Cristiane da Silva Lima, Mariana Delfino Rodrigues, Roger Lafontaine Mesquita Taborda, Najla Benevides Matos","doi":"10.1007/s10123-026-00832-1","DOIUrl":"https://doi.org/10.1007/s10123-026-00832-1","url":null,"abstract":"","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}