Applied and Environmental Microbiology最新文献

{"title":"Acidification by nitrogen metabolism triggers extracellular biopolymer production in an oleaginous yeast.","authors":"Henrique Sepúlveda Del Rio Hamacek, Oksana Tingajeva, Katharina Ostertag, Alīna Reķēna, Aleksandr Illarionov, Piia Jõul, Paola Monteiro de Oliveira, Giselle de La Caridad Martín-Hernández, Bettina Müller, Nemailla Bonturi, Volkmar Passoth, Petri-Jaan Lahtvee, Rahul Kumar","doi":"10.1128/aem.00947-25","DOIUrl":"https://doi.org/10.1128/aem.00947-25","url":null,"abstract":"<p><p>The oleaginous yeast <i>Rhodotorula toruloides</i> is a natural producer of lipids and carotenoids. However, its potential as a producer of extracellular biopolymers remains unexplored. Hence, we aimed to evaluate the <i>R. toruloides</i> CCT0783 for extracellular biopolymer production. We found that the carbon-to-nitrogen ratio influenced exopolysaccharide (EPS) production, reaching 5.84 ± 0.45 g/L under glucose-rich conditions. We characterized the crude biopolymer using FTIR and GC-MS, identifying polysaccharide peaks, wherein EPS consisted of (%) glucose (88.83 ± 4.87), galactose (5.50 ± 1.50), mannose (4.80 ± 1.57), and xylose and arabinose (0.87 ± 0.04) monomers. The dried EPS also contained a fractional presence of protein (1.0%). Interestingly, inorganic, but not organic, nitrogen metabolism was associated with the acidification of the culture environment and simultaneous EPS production. A comparison of cultivation conditions revealed that EPS was produced when metabolic activity contributed to the culture media acidification to a pH of approximately 2. Finally, a comparative bioinformatics analysis allowed us to map the putative EPS biosynthesis and transport pathways, as well as regulators of intracellular pH maintenance. In conclusion, our study demonstrates <i>R. toruloides'</i> potential as an extracellular microbial biopolymer producer, enabling its consideration for extracellular bioproduction, besides its typically reported intracellular products.IMPORTANCEMicrobial biopolymers have been extensively studied for their impact on the environment and on health. However, developing a biotechnology process for producing such biopolymers remains challenging despite their potential for valuable applications. Considering this opportunity, we investigated the oleaginous yeast <i>Rhodotorula toruloides</i> as a producer of extracellular biopolymers, which, to date, is mostly used as a cell factory for intracellular bioproducts, namely, lipids and carotenoids. Our study identifies the conditions and maps pathways that allow exopolysaccharide (EPS) production in this yeast. These biopolymers, besides highlighting <i>R. toruloides</i> potential for extracellular production, could be deployed in diverse applications, from gelling agents in pharmaceuticals to emulsifiers in the food industry. Furthermore, our comparative bioinformatics analysis provides a foundational resource that could enable the development of <i>Rhodotorula</i> cell factories for extracellular bioproduction.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0094725"},"PeriodicalIF":3.7,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145231305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biocontainment efficacy redefined.","authors":"Linda F Bisson","doi":"10.1128/aem.01610-25","DOIUrl":"https://doi.org/10.1128/aem.01610-25","url":null,"abstract":"<p><p>Biocontainment of genetically modified microorganisms (GMMs) is thought to be essential to maintain the genetic integrity and lineages of native organisms of the same species in the environment as well as to minimize any ecological risk from release of a novel genetic construct. <i>Saccharomyces cerevisiae</i>, a common agent used in food and beverage production, additionally necessitates preventing any risk to human health from accidental penetrance of the GMM in technological sites or lineages. Multiple factors need to be considered in the design of a GMM with the potential for escape to avoid unwanted consequences. Biocontainment efficacy requires understanding the full spectrum of potential ways in which release of a GMM could occur and the impact of that escape from containment on the environment. In an <i>Applied and Environmental Microbiology</i> article by N. A. Lamb et al. (91:e00741-25, 2025, https://doi.org/10.1128/aem.00741-25), the authors make the case for a more comprehensive evaluation of biocontainment of GMMs destined for industrial use and raise the critical need of developing and using sound design strategies to assure biocontainment efficacy. The authors demonstrate through analysis of mutants evading genetic biocontainment that existing design strategies have not been adequately evaluated. Although beyond the scope of this research study, sound design strategies should include minimizing the impact to the ecosystem should unintended release of the GMM occur. Potential impact of release requires a deeper understanding of the genomic plasticity of wild and domestic lineages of <i>S. cerevisiae</i>. Fortunately, an extensive analysis of the biodiversity of yeast strains isolated from natural and technological ecosystems and their genetic interactions has been conducted and may be useful in redefining concepts of biocontainment efficacy.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0161025"},"PeriodicalIF":3.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial community analysis of treponeme-associated hoof disease in free-ranging elk (<i>Cervus canadensis</i>): evidence for a polybacterial etiology with geographic consistency.","authors":"Elizabeth W Goldsmith, Kyle R Taylor, Margaret A Wild, Sushanta Deb, Tarah Sullivan, Eric Lofgren, Kyle R Garrison, Gregory M Schroeder, Carrington Hilson, Nicole L Walrath, Julia D Burco, Emma Lantz, Steven N Winter, Devendra H Shah","doi":"10.1128/aem.00888-25","DOIUrl":"https://doi.org/10.1128/aem.00888-25","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Treponeme-associated hoof disease (TAHD) is an emerging infectious disease in free-ranging elk (&lt;i&gt;Cervus canadensis&lt;/i&gt;) characterized by ulcerative and necrosuppurative pododermatitis with spirochete bacteria that leads to lameness and apparent increased mortality. While TAHD is hypothesized to have a polybacterial etiology, the causative agents remain poorly characterized, particularly across its geographic range. In this study, we developed a histologic categorization system for hoof lesions and employed 16S rRNA gene amplicon sequencing to characterize bacterial communities in samples from 129 free-ranging elk across regions with endemic or sporadic TAHD and where TAHD remains undetected. Differential abundance analysis revealed strong associations between TAHD-positive lesions and the bacterial genera &lt;i&gt;Treponema&lt;/i&gt;, unidentified &lt;i&gt;Spirochaetaceae&lt;/i&gt;, &lt;i&gt;Mycoplasma&lt;/i&gt;, and &lt;i&gt;Fusobacterium&lt;/i&gt;, along with their respective families and amplicon sequence variants. Many of these TAHD-associated operational taxonomic units (OTUs) were also more frequently detected at increased abundance in more severe, histologic lesions of pododermatitis. Correlation analysis demonstrated a strong positive association between &lt;i&gt;Treponema&lt;/i&gt; and &lt;i&gt;Mycoplasma&lt;/i&gt; in TAHD lesions, suggesting a more significant role of &lt;i&gt;Mycoplasma&lt;/i&gt; in TAHD's etiology than previously recognized. Additionally, we identified novel TAHD-associated OTUs, including &lt;i&gt;Corynebacterium freneyi-xerosis&lt;/i&gt;, that warrant further investigation. Comparative analysis of TAHD-positive lesions from endemic and sporadic areas revealed minimal differences in the microbial community. These findings advance our understanding of the bacterial contributors to TAHD, highlighting putative pathogens for further investigation and as potential targets for diagnostic development.IMPORTANCEWhile detection of &lt;i&gt;Treponema&lt;/i&gt; is a hallmark of treponeme-associated hoof disease (TAHD), a comprehensive understanding of other bacterial contributors is necessary to improve diagnostic testing and inform control measures. Our study confirmed strong associations between &lt;i&gt;Spirochaetaceae&lt;/i&gt; and TAHD lesions and revealed a previously underappreciated role of &lt;i&gt;Mycoplasma&lt;/i&gt; in TAHD's etiology. &lt;i&gt;Treponema&lt;/i&gt; and &lt;i&gt;Mycoplasma&lt;/i&gt; were significantly enriched in TAHD-positive lesions, absent from TAHD-negative tissues, and strongly and positively correlated with each other, suggesting a potential synergistic relationship. By developing and applying a histologic categorization system, we characterized shifts in bacterial communities as lesion severity progressed. Comparisons of TAHD-positive lesions from endemic and sporadic regions revealed minimal differences in the microbial composition, indicating strong geographic consistency. These findings enhance our understanding of TAHD's etiology and provide a foundation for future research, including the development of improved diagnostic tests and ta","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0088825"},"PeriodicalIF":3.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoinactivation of influenza viruses by modulated indoor daylight spectrum and intensity.","authors":"Michael Zhao, Kinga Vojnits, Man In Lam, Sam Yeo, Piers MacNaughton, Sepideh Pakpour","doi":"10.1128/aem.00973-25","DOIUrl":"https://doi.org/10.1128/aem.00973-25","url":null,"abstract":"<p><p>Influenza claims over 290,000 lives annually, and the annual flu season remains a major public health challenge. Within the domain of health-focused architectural design, indoor daylight emerges as a potential shield against microbial threats. Yet, a significant gap in our understanding remains: the effect of indoor daylight on viruses. To bridge this knowledge gap, we used a living lab setup to investigate the impact of modulated indoor daylight on the stability of genomic material and persistence of infectivity of enveloped influenza A and B viruses, along with the non-enveloped bacteriophage MS2 on an environmental surface of glass. Indoor daylight modulation showed capacity for viral inactivation with differential activity depending on spectrum, intensity, and duration of exposure. Intensity was the most impactful, significantly reducing the infectivity of influenza A virus and both the infectivity and amount of recoverable genomic material of influenza B virus following 8 h of exposure. Even at low-intensity light, comparable to light passing through traditional blinds, spectrum-modulated, blue-enriched light significantly reduced the infectivity of influenza A and B within 8 h. Moreover, for all viruses, the infectivity declined before the stability of genomic material, suggesting a mechanism of photoinactivation via the disruption of viral proteins involved in infection. This research emphasizes the paramount importance of considering daylighting conditions as a strategic approach to control infectious disease transmission in built environments. Our findings not only underscore this significance but also offer innovative pathways to transform indoor spaces into safer, healthier environments for everyone.IMPORTANCEThis study examined the interplay between indoor daylighting and viruses, specifically influenza A, influenza B, and MS2 bacteriophage in a simulated indoor environment on a surface material of glass. It demonstrated that indoor daylight modulation was able to inactivate influenza A and B following 8 h of exposure at high-intensity and low-intensity blue-enriched light; however, the stability of genomic material of influenza A was unaffected until at least 24 h of exposure. These results, which focus on differences between stability of genomic material and infectivity, provide deeper insight into viral photoinactivation mechanisms, and the use of a living-lab setup lays the foundation for a framework for healthy building design using indoor daylight modulation for infection control.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0097325"},"PeriodicalIF":3.7,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A distinct subpopulation of membrane vesicles in <i>Pseudomonas putida</i> is enriched in enzymes for lignin catabolism.","authors":"Allison Z Werner, Richard J Giannone, Matthew J Keller, Christine Plavchak, Dana L Carper, Paul E Abraham, Rebecca A Wilkes, Ludmilla Aristilde, Davinia Salvachúa, S Kim Ratanathanawongs Williams, Robert L Hettich, Gregg T Beckham","doi":"10.1128/aem.01617-25","DOIUrl":"https://doi.org/10.1128/aem.01617-25","url":null,"abstract":"<p><p>Bacterial membrane vesicles (MVs) mediate diverse microbial processes and are emerging as powerful biomedical tools, but MV population heterogeneity remains an open question. Here, we separate, enumerate, and characterize two MV populations from the soil bacterium <i>Pseudomonas putida</i> during growth with or without lignin-derived carbon, a major carbon source from plant cells in the rhizosphere. Small MVs (MV-S, diameter ~100 nm) were produced from all cultures, whereas large MVs (MV-L, diameter ~300 nm) were observed during the late stationary phase of lignin cultivations. MV-S contained selectively packaged proteins with diverse physiological functions, whereas the MV-L proteome was smaller and largely enriched in outer membrane proteins. Interestingly, enzymes known to mediate the catabolism of lignin-derived aromatic compounds were enriched in MV-S. Overall, this study highlights the need for careful consideration of MV populations in microbial systems.IMPORTANCEMembrane vesicles (MVs) are extracellular lipid bodies that can be generated by single-cell microbes and contain biological cargo. Since their discovery, MVs have been shown to exhibit multiple functions, including nutrient acquisition, pathogenesis, and signaling. In soil, the breakdown of plants releases aromatic compounds from lignin, and it has been previously shown that a model bacterium that consumes aromatic compounds forms MVs with enzymes responsible for the consumption of aromatic compounds. Intriguingly, a small population and a large population of MVs were observed, and it was not known if they served the same or different functions. Here, MVs isolated from bacterial growth experiments on lignin were fractionated and characterized, revealing that distinct MV populations have distinct cargo and, thus, distinct functions.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0161725"},"PeriodicalIF":3.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 the bacterial and fungal diversity in habitats of Corsica Island.","authors":"Sonia Aghzaf, Jean-Pierre Poli, Marion Brunel, Jean Costa, Vannina Lorenzi, Elodie Guinoiseau, Liliane Berti","doi":"10.1128/aem.00756-25","DOIUrl":"https://doi.org/10.1128/aem.00756-25","url":null,"abstract":"<p><p>Indoor environments may impact human health significantly since microbial diversity made of various bacteria, fungi, and other microorganisms constitutes the habitat's microbiome. These microorganisms originate from diverse sources, such as the environment, humans, and pets. Understanding such microbial diversity is crucial for assessing related health impacts. The aim of this study was to investigate bacterial and fungal microorganisms from different surfaces in a set of houses on Corsica Island (southeastern France). We conducted sampling and high-throughput sequencing of PCR-amplified microbial DNA from 40 habitats (eight different surfaces tested for each) located on diverse regions of the island. Following nucleic acid recovery, we performed PCR targeting V3-V4 regions of 16S rRNA for bacteria and ITS1 region for fungi. Bioinformatics processing allowed the identification of distinct microbial species and the analysis of their distribution. Our findings highlighted that the most represented bacterial genera in the Corsican homes tested were <i>Ralstonia</i> (16.9%), <i>Staphylococcus</i> (4.8%), <i>Corynebacterium</i> (2.7%), <i>Enhydrobacter</i> (6.8%), and <i>Methylorubrum</i> (6.0%). Regarding fungal diversity, the most common genera identified were <i>Dipodascaceae</i> (21.6%), <i>Rhodotorula</i> (10.9%), <i>Aspergillus</i> (8.9%), <i>Clavispora</i> (7.3%), and <i>Candida</i> (6.8%). Our results also showed differences in microbial composition among the habitats studied, while a higher bacterial and fungal diversity was observed in rural habitats and in those with pets.IMPORTANCEThis study provides valuable insights into the microbial diversity present in indoor environments of Corsican homes, specifically highlighting bacterial and fungal communities on various household surfaces. By identifying the predominant microbial genera and revealing differences linked to habitat characteristics, such as rural settings and pet ownership, this research enhances our understanding of how indoor microbial communities vary.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0075625"},"PeriodicalIF":3.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antifungal and other bioactive properties of the volatilome of <i>Streptomyces scabiei</i>.","authors":"Nudzejma Stulanovic, Djulia Bensaada, Loïc Belde, Delphine Adam, Marc Hanikenne, Jean-François Focant, Pierre-Hugues Stefanuto, Sébastien Rigali","doi":"10.1128/aem.00863-25","DOIUrl":"https://doi.org/10.1128/aem.00863-25","url":null,"abstract":"<p><p>Volatile compounds (VCs) produced by most host-associated bacteria remain largely unexplored despite their potential roles in suppressing microbial competitors and facilitating host colonization. This study investigated the volatilome of <i>Streptomyces scabiei</i> 87-22, the model species for causative agents of common scab in root and tuber crops, under culture conditions that completely inhibited fungal growth, including the phytopathogens <i>Alternaria solani</i> and <i>Gibberella zeae</i>. Bicameral assays confirmed that these effects were partially due to VCs. Using gas chromatography coupled with time-of-flight mass spectrometry, 36 VCs were unambiguously identified as products of <i>S. scabiei</i> 87-22 metabolic activity. These included mainly ketones and aromatic compounds (both benzene derivatives and heterocycles), along with smaller contributions from other chemical families, including sulfur-containing compounds, nitriles, esters, terpenoids, an amide, and an aldehyde. A literature survey suggests that many of these VCs possess antibacterial, antifungal, anti-oomycete, nematocidal, and insecticidal effects, while the bioactivity of others remains speculative, having been identified only within complex volatile mixtures. Among those with known antifungal properties, dimethyl trisulfide, 2-heptanone, and creosol inhibited the growth of the fungal pathogens tested in this study. In addition, we reveal here that 3-penten-2-one is also a strong inhibitor of fungal growth. Remarkably, despite <i>S. scabiei</i> 87-22 being defined as a pathogen, some of its VCs were associated with plant growth promotion and defense stimulation. Overall, our work highlights the remarkable potential of <i>S. scabiei</i> 87-22 to produce VCs with diverse antagonistic activities and suggests that its ecological function in nature is likely more complex than the current view, exclusively centered on its pathogenicity.</p><p><strong>Importance: </strong>This study reveals that <i>Streptomyces scabiei</i>, the bacterium causing common scab in root and tuber crops, produces a wide variety of volatile chemicals with surprising benefits. These natural compounds can inhibit the growth of other harmful microbes, including fungal plant pathogens. Some of these chemicals are already known to fight pests and diseases, while others, like 3-penten-2-one, are newly discovered as potential antifungals. Even more unexpectedly, some of the identified compounds may help plants grow or boost their defenses. Combined with previous work, our findings challenge the idea that <i>S. scabiei</i> is purely harmful and suggest it might, under certain conditions, stimulate plant defense and can act protectively in its environment.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0086325"},"PeriodicalIF":3.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tellurite and selenite processing by tellurite resistant marine microbes.","authors":"Patrick Ollivier, Thomas Hanson, Emmanuel Tessier, David Amouroux, Thomas Church","doi":"10.1128/aem.00881-25","DOIUrl":"https://doi.org/10.1128/aem.00881-25","url":null,"abstract":"<p><p>Understanding microbial transformations of the group VIa/16 metalloids tellurium and selenium is important for the remediation of contaminated environments and has been proposed as a green route for Se/Te nanoparticle synthesis. We previously isolated several strains of aerobic tellurite resistant marine yeast and bacteria. Here, we explored the capability of these strains to metabolize selenite and mixtures of tellurite and selenite to quantify fate and identify volatile metabolic products. The experimental results indicate that selenite is metabolized differently than tellurite by the yeast <i>Rhodotorula mucilaginosa</i> and bacteria <i>Bacillus</i> spp. and <i>Virgibacillus halodenitrificans</i>. The production of volatile Se compounds appears to be positively correlated with selenite resistance. However, selenite fate, e.g., the proportion of volatilized or precipitated Se, was not predictable from tellurite resistance or fate of the same strain. Under non-aerated conditions, when cultures were provided mixtures of selenite and tellurite, tellurite strongly influenced the fate of selenite and the types of volatile products made. Tellurite in oxyanion mixtures appears to strongly inhibit Se volatilization and drive speciation to less complex Se volatiles. Mixtures boosted the production of Te and Se precipitates by <i>Bacillus</i> sp. strain 6A and the production of Te precipitates by <i>Rhodotorula mucilaginosa</i> strains 13B and decreased the production of both volatile Te and Se compounds. Dimethylselenide and dimethyltelluride are acutely toxic by inhalation and oral exposure, so understanding their production is a key consideration in any biologically based manufacture of Se/Te containing nanoparticles.IMPORTANCEMany microbes are remarkably resistant to high concentrations of both selenite and tellurite while producing less toxic and bioavailable elemental forms, providing opportunities for the remediation of contaminated environments and green biosynthesis of Se/Te nanoparticles. The toxicity of volatile tellurite and selenite compounds produced during microbial processing may limit the development of remediation and biosynthesis technologies. The precise biochemical mechanisms governing Te and Se fate are still unclear. The data presented here demonstrate that combining Se and Te influenced the tolerance of marine microbes (<i>Rhodotorula mucilaginosa</i> 13B and <i>Bacillus</i> sp. strain 6A) to tellurite, significantly increasing precipitation as a product while limiting volatilization with the implication that combined Se/Te microbial remediation and/or nanoparticle synthesis may be less problematic than single element processes.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0088125"},"PeriodicalIF":3.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planetary microbiology: microbes, planets, and the search for life.","authors":"Betül Kaçar","doi":"10.1128/aem.00241-25","DOIUrl":"https://doi.org/10.1128/aem.00241-25","url":null,"abstract":"<p><p>Life on Earth has been shaped by transformative microbial innovations and singularities that redefined planetary systems, from oxygenic photosynthesis to biological nitrogen fixation. These unique events, occurring only once in life's tractable history, laid the foundation for the complex ecosystems and global biogeochemical cycles around us today. The Planetary Microbiology collection in <i>Applied and Environmental Microbiology</i> explores how modern microbiological tools reveal the origins, early evolution, and planetary impacts of these microbial breakthroughs. Spanning deep-time studies, extreme environments, and astrobiology, contributions in this issue link biosignatures and ancient microbes to the search for extraterrestrial life. By bridging molecular, ecological, and planetary scales, planetary microbiology illuminates life's past while critically informing strategies for the environmental and exploration challenges of our future.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0024125"},"PeriodicalIF":3.7,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of simulated microgravity on biological features and virulence of the fungal pathogen <i>Cryptococcus neoformans</i>.","authors":"Tanaporn Phetruen, Salinthip Thongdechsri, Muthita Khongthongdam, Sittiporn Channumsin, Krai Meemon, Sittinan Chanarat","doi":"10.1128/aem.01435-25","DOIUrl":"https://doi.org/10.1128/aem.01435-25","url":null,"abstract":"<p><p><i>Cryptococcus neoformans</i> is a fungal pathogen that causes cryptococcal meningitis, mainly in immunocompromised individuals, such as those with HIV. Its recent detection on the International Space Station raises concerns about potential health risks in space, where immune systems may be compromised. However, its behavior in space-like conditions remains unclear. In this study, we examined the effects of simulated microgravity on <i>C. neoformans</i>. We found that the condition enhanced the fungus's resistance to membrane and osmotic stress and increased key virulence factors, including capsule formation, melanin production, and urease activity. Using <i>Caenorhabditis elegans</i> as a host model, infections under simulated microgravity were more pathogenic. These findings highlight the potential for increased fungal virulence in space and underscore the need to understand microbial risks for astronaut health and safety in long-term space missions.IMPORTANCEFungi have long been recognized for their remarkable ability to adapt to a wide range of environmental conditions, including extreme environments, such as space habitats. Understanding how fungal organisms, especially pathogenic fungi, adapt to these harsh conditions is crucial for gaining insight into their tolerance mechanisms and the potential emergence of virulence. Our research demonstrates that the pathogenic fungus <i>Cryptococcus neoformans</i> not only survives in space-like conditions but also exhibits increased stress tolerance, enhanced expression of key virulence factors, and elevated pathogenicity in animal models. These findings carry significant practical implications because concerns about fungal contamination in space or other extreme environments may be heightened by the potential for fungi to develop increased virulence through natural adaptation.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0143525"},"PeriodicalIF":3.7,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}