Microbiological research最新文献_第2页

The contribution of root border cells as a defense barrier against soil-borne pathogen Verticillium dahliae: Insights from the host cotton and the non-host corn 根缘细胞对土壤病原菌大丽花黄萎病的防御屏障的贡献：来自寄主棉花和非寄主玉米的见解

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-23 DOI: 10.1016/j.micres.2026.128452

Sen Zhang , Xiaoyu Wang , Dan Zhang , Ruichi Hua, Yijin Yan, Juan Yang, Jinhu Ma, Jie Wang, Xiaohuan Yang

Verticillium wilt can be caused by the soil-borne fungal pathogen Verticillium dahliae (V. dahliae). It is a destructive vascular pathogen that infects more than 200 plant species, including economically important crops such as cotton. The disease induces severe symptoms such as wilting, chlorosis, and necrosis, ultimately resulting in substantial yield losses. Conventional management strategies, including chemical fungicides and crop rotation, have exhibited limited effectiveness against V. dahliae, emphasizing the urgent need to elucidate innate plant resistance mechanisms for breeding Verticillium-resistant varieties. In this study, the defense mechanisms of root border cells (RBCs) against V. dahliae were investigated. Fluorescence microscopy and cryo-scanning electron microscopy demonstrated that RBCs were viable and free cells, exhibiting round, intermediate, and elongated morphologies. In vitro co-culture assays revealed that viable RBCs isolated from cotton or corn markedly suppressed the growth of V. dahliae, whereas heat-inactivated RBCs lost this antifungal capacity, confirming that the defense mechanism was viability-dependent. Further analysis indicated that under V. dahliae stress, RBCs secreted a thickened mucilage layer enriched in pectin and extracellular DNA (exDNA), which encapsulated fungal hyphae and formed a physical barrier. Metabolomic profiling of RBC secretions from both cotton and corn identified a conserved set of metabolites, including compounds involved in flavone and flavonol biosynthesis, valine, leucine, and isoleucine metabolism, and phenylpropanoid biosynthesis, which could contribute to chemical defense against pathogens. These findings demonstrate the cellular and molecular mechanisms underlying RBC-mediated inhibition of V. dahliae infection and provide insights for developing Verticillium wilt resistance breeding strategies in cotton.

黄萎病可由土壤传播的真菌病原菌大丽花黄萎病（vdahliae）引起。它是一种破坏性的维管病原体，感染200多种植物，包括经济上重要的作物，如棉花。该病引起严重的症状，如萎蔫、黄化和坏死，最终导致大量产量损失。传统的管理策略，包括化学杀菌剂和作物轮作，对大丽花弧菌的有效性有限，因此迫切需要阐明植物的先天抗性机制，以培育抗黄萎病的品种。本研究探讨了根缘细胞对大丽花的防御机制。荧光显微镜和冷冻扫描电镜显示红细胞是有活力的游离细胞，表现出圆形、中间和细长的形态。体外共培养实验表明，从棉花或玉米中分离的活红细胞明显抑制大丽花弧菌的生长，而热灭活红细胞则失去了这种抗真菌能力，证实了防御机制依赖于活力。进一步分析表明，在大丽弧菌胁迫下，红细胞分泌一层增厚的富含果胶和细胞外DNA （exDNA）的粘液层，包裹真菌菌丝，形成物理屏障。棉花和玉米红细胞分泌物的代谢组学分析发现了一组保守的代谢物，包括与黄酮和黄酮醇生物合成、缬氨酸、亮氨酸和异亮氨酸代谢以及苯丙素生物合成有关的化合物，这些化合物可能有助于抵抗病原体的化学防御。这些发现揭示了红血球介导的抑制大丽花枯萎病的细胞和分子机制，并为制定棉花抗黄萎病育种策略提供了见解。

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引用次数: 0

The effect of Sinorhizobium meliloti volatilomes and synthetic long-chain methylketones on soil and Medicago truncatula microbiomes 中华根瘤菌挥发物和合成长链甲酮对土壤和苜蓿微生物群的影响

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-20 DOI: 10.1016/j.micres.2026.128456

Pieter van Dillewijn , Lydia M. Bernabéu-Roda , Virginia Cuéllar , Rafael Núñez , Otto Geiger , Isabel M. López-Lara , María J. Soto

Bacterial volatile compounds play important roles in intra- and interkingdom interactions but little is known about their effects on soil and plant microbiomes. The legume symbiont Sinorhizobium meliloti (Sm) releases volatile methylketones (MKs), one of which acts as an infochemical among bacteria and hampers plant-bacteria interactions. Inactivation of the fatty acyl-CoA ligase FadD in Sm moderately enhances MK production. To further explore the ecological role of MKs on soil and plant bacterial communities, we aimed at obtaining an MK-overproducing Sm strain by deleting the 3-oxoacyl-CoA thiolase-encoding fadA gene. Analyses of the Sm wild-type (WT) and fad mutant volatilomes identified seventeen compounds, primarily consisting of MKs and fatty acid methyl esters (FAMEs). The fadA mutant released more MKs than the fadD mutant, and substantially more than the WT, whereas FAME emission was increased in the fadD mutant. Exposure of natural soil and the Medicago truncatula rhizosphere to WT and fadA volatilomes or synthetic volatile MKs did not significantly alter bacterial alpha or beta diversity but certain genera responded differentially to each condition. Interestingly, Sm volatilomes significantly affected root endosphere Ensifer/Sinorhizobium populations by maintaining their abundance over time, in contrast to control conditions or exposure to synthetic volatile MKs. This study provides new insights on the synthesis of rhizobial volatile compounds and represents the first exploration of the effects of rhizobial volatilomes on soil and plant bacterial communities, contributing to a deeper understanding of the complex molecular bases underlying plant-bacteria interactions.

细菌挥发性化合物在王国内和王国间的相互作用中发挥重要作用，但对其对土壤和植物微生物组的影响知之甚少。豆科植物共生体Sinorhizobium meliloti （Sm）释放挥发性甲基酮（mk），其中一种甲基酮在细菌中起信息化学作用，阻碍植物与细菌的相互作用。Sm中脂肪酰基辅酶a连接酶FadD的失活适度地促进MK的产生。为了进一步探索mk对土壤和植物细菌群落的生态作用，我们旨在通过删除编码fadA基因的3-氧酰基辅酶a硫酶获得一个过量生产mk的Sm菌株。对Sm野生型（WT）和fad突变体挥发物的分析鉴定出17种化合物，主要由mk和脂肪酸甲酯（FAMEs）组成。fadA突变体比fadD突变体释放更多的mk，并且比WT多得多，而fadD突变体的FAME释放增加。自然土壤和苜蓿根际暴露于WT和fadA挥发物或合成挥发物mk对细菌α和β多样性的影响不显著，但某些属对每种条件的反应存在差异。有趣的是，与对照条件或暴露于合成挥发性mk相比，Sm挥发物随着时间的推移保持其丰度，从而显著影响根内圈Ensifer/Sinorhizobium种群。该研究为根瘤菌挥发性化合物的合成提供了新的见解，并首次探索了根瘤菌挥发性物质对土壤和植物细菌群落的影响，有助于更深入地了解植物与细菌相互作用的复杂分子基础。

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引用次数: 0

Cobalamin-mediated protection of Faecalibacterium duncaniae against oxidative stress: Insights from proteomic and membrane fatty acid profiles 钴胺介导的粪杆菌抗氧化应激保护：来自蛋白质组学和膜脂肪酸谱的见解

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-20 DOI: 10.1016/j.micres.2026.128455

Maria Alejandra de Angel Fontalvo , Simon Ménard , Rime Chebbo , Jasmina Vidic , Alban Amoros , Christine Péchoux , Lydie Oliveira Correia , Sébastien Dupont , Florence Dubois-Brissonnet , Laurent Beney , Bonastre Oliete , Jean-Marc Chatel , Sandrine Auger

Faecalibacterium species are keystone commensals of the human gut, contributing to intestinal homeostasis, immune modulation, and epithelial health. However, their extreme sensitivity to oxygen and reactive oxygen species renders them highly vulnerable during inflammatory conditions, severely limiting their therapeutic application. Understanding the molecular mechanisms underlying their oxidative stress responses is therefore critical for harnessing these bacteria as next-generation probiotics to restore gut health. In this study, we investigated oxidative stress responses in Faecalibacterium duncaniae A2–165 using comprehensive proteomic and membrane fatty acid profiling. We demonstrated that increasing hydrogen peroxide (H₂O₂) concentrations extend the lag phase of growth and affect survival during the first hour of exposure, notably altering the redox potential. Exposure to H₂O₂ triggered a remodeling of the proteome, including detoxification systems, metal transporters, DNA repair systems, transcriptional regulators, and enzymes involved in cobalamin biosynthesis. Complementary RT-qPCR analyses revealed coordinated and time-dependent transcriptional activation of genes involved in oxidative stress response. Remarkably, cobalamin supplementation enhanced bacterial growth, mitigated H₂O₂-induced stress, and lowered superoxide levels in F. duncaniae, highlighting its direct antioxidant activity. By analyzing membrane fatty acid profiles, we showed that cobalamin preserves membrane fluidity, counteracting oxidative stress induced by H₂O₂ in F. duncaniae. These findings reveal the multifaceted strategies employed by F. duncaniae to withstand oxidative stress and provide a foundation for future efforts to optimize its production at industrial scales and its therapeutic potential as a next-generation probiotic.

粪杆菌是人类肠道的重要共生体，有助于肠道稳态、免疫调节和上皮健康。然而，它们对氧气和活性氧的极端敏感性使得它们在炎症条件下非常脆弱，严重限制了它们的治疗应用。因此，了解其氧化应激反应的分子机制对于利用这些细菌作为下一代益生菌来恢复肠道健康至关重要。在这项研究中，我们利用综合蛋白质组学和膜脂肪酸谱研究了粪杆菌A2-165的氧化应激反应。我们证明，过氧化氢（H₂O₂）浓度的增加延长了生长的滞后期，并在暴露的第一个小时内影响了存活，特别是改变了氧化还原电位。暴露于h2o2会引发蛋白质组的重塑，包括解毒系统、金属转运体、DNA修复系统、转录调节因子和参与钴胺素生物合成的酶。互补的RT-qPCR分析揭示了参与氧化应激反应的基因的协调和时间依赖性转录激活。值得注意的是，补充钴胺素可以促进细菌生长，减轻h2o2诱导的应激，降低f.d caniae中的超氧化物水平，突出其直接抗氧化活性。通过分析膜脂肪酸谱，我们发现钴胺素保持了膜的流动性，抵消了F. duncaniae中h2o2诱导的氧化应激。这些发现揭示了duncaniae抵御氧化应激的多方面策略，并为未来在工业规模上优化其生产及其作为下一代益生菌的治疗潜力提供了基础。

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引用次数: 0

Comparative pan-genomics and in vivo validation identify genetic factors important for virulence of Salmonella enterica serovar Gallinarum and serovar Enteritidis in the avian host 比较泛基因组学和体内验证确定了鸡肠炎沙门氏菌血清型和肠炎沙门氏菌血清型在禽宿主体内毒力的重要遗传因素

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-19 DOI: 10.1016/j.micres.2026.128453

Xiao Fei , Jennifer Moussa , Priscila Regina Guerra , Sajid Nisar , Yibing Ma , Weizhe Wang , Mauro M.S. Saraiva , Heng Li , Zhemin Zhou , John Elmerdahl Olsen

Salmonella enterica subspecies enterica serovar Gallinarum biovar Gallinarum (SGa) and Pullorum (SPu) are avian-specific pathogens causing systemic disease, while S. Enteritidis (SEnt) is a broad host range serovar causing gastroenteritis. The genomic mechanisms underlying this difference in host range and pathogenicity remain incompletely understood. Here, we performed a large-scale pan-genome analysis of 5440 poultry-derived genomes (4927 SEnt, 106 SGa, 407 SPu) integrated with functional chicken and macrophage experiments. Compared with SEnt, avian-specific SGa and SPu exhibited extensive pseudogenization and shared 87 genes absent in SEnt, organized into four major genomic clusters (PG_1–PG_4) enriched in type VI secretion system genes and prophage-derived elements. Conserved SNPs distinguishing SGa/SPu from SEnt were enriched in carbohydrate and nitrogen metabolism pathways, suggesting potential metabolic divergences during infection. Infection experiments in chickens using deletion mutants revealed that deletions of genes in SPI-2 (ssaE, ssaT) and fimbrial genes (stfA, safA) were important for systemic infection of chicken with both SGa and SEnt, despite pseudogenization of fimbrial operons in SGa. Mutants in SPI-13 and SPI-14 were only significantly attenuated in SGa. The specific prophage region PG_3 was important for systemic infection in SGa, while a distinct prophage element (ENT_2) enhanced infection in SEnt. Together, these findings bridge comparative genomics with experimental validation, identifying genomic degradation, prophage acquisition, and serovar-specific pathogenicity islands as putative mechanisms underlying avian host specificity and systemic pathogenesis in Salmonella.

肠沙门氏菌亚种肠沙门氏菌血清型（enterica serovar Gallinarum biovar Gallinarum, SGa）和鸡痢沙门氏菌（Pullorum, SPu）是引起全身性疾病的禽类特异性病原体，而肠炎沙门氏菌（SEnt）是引起肠胃炎的广泛宿主血清型。这种宿主范围和致病性差异背后的基因组机制尚不完全清楚。在此，我们结合功能鸡和巨噬细胞实验，对5440个家禽衍生基因组（4927个SEnt， 106个SGa， 407个SPu）进行了大规模泛基因组分析。与send相比，禽类特异性SGa和SPu具有广泛的假原性，并共享了send中缺失的87个基因，这些基因被组织成4个主要的基因组簇（PG_1-PG_4），富含VI型分泌系统基因和噬菌体衍生元件。区分SGa/SPu和SEnt的保守snp在碳水化合物和氮代谢途径中富集，表明感染期间可能存在代谢差异。用缺失突变体对鸡进行的感染实验表明，尽管SGa的毛膜操纵子会假原化，但SPI-2基因（ssaE、ssaT）和毛膜基因（stfA、safA）的缺失对SGa和SEnt的鸡的全身感染都很重要。SPI-13和SPI-14突变体仅在SGa中显著减弱。特异性前噬菌体区PG_3对SGa的全身感染很重要，而特异性前噬菌体元件（ENT_2）对send的感染有促进作用。总之，这些发现将比较基因组学与实验验证结合起来，确定了基因组降解、原噬菌体获得和血清特异性致病性岛是沙门氏菌禽宿主特异性和系统性发病机制的假定机制。

{"title":"Comparative pan-genomics and in vivo validation identify genetic factors important for virulence of Salmonella enterica serovar Gallinarum and serovar Enteritidis in the avian host","authors":"Xiao Fei , Jennifer Moussa , Priscila Regina Guerra , Sajid Nisar , Yibing Ma , Weizhe Wang , Mauro M.S. Saraiva , Heng Li , Zhemin Zhou , John Elmerdahl Olsen","doi":"10.1016/j.micres.2026.128453","DOIUrl":"10.1016/j.micres.2026.128453","url":null,"abstract":"<div><div><em>Salmonella enterica</em> subspecies <em>enterica</em> serovar Gallinarum biovar Gallinarum (SGa) and Pullorum (SPu) are avian-specific pathogens causing systemic disease, while <em>S</em>. Enteritidis (SEnt) is a broad host range serovar causing gastroenteritis. The genomic mechanisms underlying this difference in host range and pathogenicity remain incompletely understood. Here, we performed a large-scale pan-genome analysis of 5440 poultry-derived genomes (4927 SEnt, 106 SGa, 407 SPu) integrated with functional chicken and macrophage experiments. Compared with SEnt, avian-specific SGa and SPu exhibited extensive pseudogenization and shared 87 genes absent in SEnt, organized into four major genomic clusters (PG_1–PG_4) enriched in type VI secretion system genes and prophage-derived elements. Conserved SNPs distinguishing SGa/SPu from SEnt were enriched in carbohydrate and nitrogen metabolism pathways, suggesting potential metabolic divergences during infection. Infection experiments in chickens using deletion mutants revealed that deletions of genes in SPI-2 (<em>ssaE</em>, <em>ssaT</em>) and fimbrial genes (<em>stfA</em>, <em>safA</em>) were important for systemic infection of chicken with both SGa and SEnt, despite pseudogenization of fimbrial operons in SGa. Mutants in SPI-13 and SPI-14 were only significantly attenuated in SGa. The specific prophage region PG_3 was important for systemic infection in SGa, while a distinct prophage element (ENT_2) enhanced infection in SEnt. Together, these findings bridge comparative genomics with experimental validation, identifying genomic degradation, prophage acquisition, and serovar-specific pathogenicity islands as putative mechanisms underlying avian host specificity and systemic pathogenesis in <em>Salmonella</em>.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"306 ","pages":"Article 128453"},"PeriodicalIF":6.9,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Protective role of the gut microbiota against Listeria monocytogenes: From colonization resistance to therapeutic approaches 肠道菌群对单核增生李斯特菌的保护作用：从定植抗性到治疗方法

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-19 DOI: 10.1016/j.micres.2026.128454

Junnan Huang , Xuejuan Xia , Jing Lu , Xuanyu Chen , Keyao Ye , Jia Yu , Zhuosi Li , Yue Ma , Xiaojie Qin , Yangtai Liu , Xiang Wang , Hai Chi , Guannan Li , Chang Liu , Qingli Dong

Listeria monocytogenes (LM) is a significant foodborne pathogen with considerable resilience in diverse environments. Following ingestion via contaminated food, LM can breach the intestinal barrier and infect target organs, causing systemic infection. This breach represents a critical step in its pathogenesis. The gut microbiota, a key component of intestinal defense, can restrict the colonization and invasion of the pathogen through mechanisms such as nutrient competition and bacteriocin production. In response, LM has evolved counterstrategies to enhance its survival and invasiveness in the gut environment. Furthermore, the efficacy of the gut microbiota in resisting LM is influenced by multiple factors, such as population differences and dietary habits, leading to variations in susceptibility to infection among individuals. Currently, antibiotic therapy for listeriosis faces limitations, highlighting the need for alternative control and therapeutic strategies. This review systematically summarizes the mechanisms by which the gut microbiota resists LM, the adaptive strategies of the pathogen, and the factors influencing this interaction. It also discusses current microbiota-based preventive and therapeutic approaches, aiming to provide a theoretical foundation for future research.

单核细胞增生李斯特菌（LM）是一种重要的食源性病原体，在不同的环境中具有相当的适应力。LM通过受污染的食物摄入后，可突破肠道屏障，感染目标器官，引起全身性感染。这一突破是其发病机制的关键一步。肠道微生物群是肠道防御的关键组成部分，可以通过营养竞争和细菌素产生等机制限制病原体的定植和入侵。因此，LM进化出了对抗策略来提高其在肠道环境中的生存和侵袭性。此外，肠道菌群抵抗LM的效果受到多种因素的影响，如人群差异和饮食习惯，导致个体对感染的易感性存在差异。目前，李斯特菌病的抗生素治疗面临局限性，强调需要替代控制和治疗策略。本文系统综述了肠道菌群抵抗LM的机制、病原菌的适应策略以及影响这种相互作用的因素。讨论了目前基于微生物群的预防和治疗方法，旨在为未来的研究提供理论基础。

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引用次数: 0

Natural product honokiol exerts anti-methicillin resistant Staphylococcus aureus infection activity by targeting pyruvate kinase to inhibit glucose metabolism 天然产物厚朴酚通过靶向丙酮酸激酶抑制葡萄糖代谢，发挥抗耐甲氧西林金黄色葡萄球菌感染活性

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-15 DOI: 10.1016/j.micres.2026.128451

Jingwen Bai, Jinjin Zheng, Chi Wei, Bin Yu, Jingwen Sun, Ziyang Feng, Yu Yang

The global spread of methicillin-resistant Staphylococcus aureus (MRSA) urgently demands novel therapeutic strategies. This study demonstrates that honokiol (HNK), a natural biphenolic compound, is a potent and broad-spectrum agent against MRSA, including clinical isolates. HNK exhibited rapid bactericidal activity, effectively disrupted biofilms, and in a murine abscess model, significantly promoted wound healing while reducing pro-inflammatory cytokines, with excellent biocompatibility. Through an integrated multi-omics, biochemical, and biophysical approach, we identified pyruvate kinase (PYK), the terminal enzyme of glycolysis, as the primary cellular target. Remarkably, HNK employs a dual-targeting strategy, concurrently inhibiting PYK enzyme activity and downregulating pyk gene transcription. Molecular docking, dynamics simulations, and computational mutagenesis delineated the precise binding mode and validated key interaction residues. This concerted attack triggers a catastrophic metabolic cascade severe obstruction of glycolytic flux, impairment of the TCA cycle, profound depletion of ATP/NADH, and oxidative stress ultimately leading to bacterial death and virulence attenuation. Our findings not only elucidate a novel antibacterial mechanism centered on the simultaneous transcriptional and functional inhibition of a metabolic hub but also provide a structural basis for drug design, positioning HNK as a valuable lead compound against multidrug-resistant staphylococcal infections. The definitive genetic validation of PYK as the essential target remains the critical next step to advance this therapeutic strategy.

耐甲氧西林金黄色葡萄球菌（MRSA）的全球传播迫切需要新的治疗策略。本研究表明，作为一种天然双酚类化合物，honokiol （HNK）是一种有效的广谱抗MRSA药物，包括临床分离株。HNK具有快速杀菌活性，有效破坏生物膜，并在小鼠脓肿模型中显著促进伤口愈合，同时减少促炎细胞因子，具有良好的生物相容性。通过综合多组学、生化和生物物理方法，我们确定了糖酵解的末端酶丙酮酸激酶（pyruvate kinase， PYK）是主要的细胞靶点。值得注意的是，HNK采用双靶向策略，同时抑制PYK酶活性和下调PYK基因转录。分子对接，动力学模拟和计算诱变描绘了精确的结合模式和验证了关键的相互作用残基。这种协同攻击引发了灾难性的代谢级联反应：糖酵解通量严重受阻，TCA循环受损，ATP/NADH严重耗竭，氧化应激最终导致细菌死亡和毒力衰减。我们的研究结果不仅阐明了一种以代谢中心同时转录和功能抑制为中心的新型抗菌机制，而且为药物设计提供了结构基础，将HNK定位为抗多药耐药葡萄球菌感染的有价值的先导化合物。PYK作为基本靶点的明确遗传验证仍然是推进这种治疗策略的关键下一步。

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引用次数: 0

Genomic insights into high-yield carotenoid production from renewable resources in radiation-resistant Deinococcus yunweiensis KCTC3955 and its optimization through fed-batch fermentation 耐辐射云维Deinococcus yunweiensis KCTC3955可再生资源高产类胡萝卜素的基因组学研究及其分批补料发酵优化

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-14 DOI: 10.1016/j.micres.2026.128443

Chi Young Hwang , Eui-Sang Cho , Soyoung Jeong , Jong-Hyun Jung , Myung-Ji Seo

The environmental impacts of climate change highlight the need for sustainable bioprocesses using low-cost feedstocks. Microbial fermentation offers an eco-friendly method to produce value-added compounds from renewable resources. Deinoxanthin, a unique carotenoid pigment produced by radiation-resistant bacteria, Deinococcus, has pharmaceutical and food industry applications. However, most microorganisms preferentially utilize glucose as their primary carbon source, limiting their capacity to ferment byproducts or waste-derived resources effectively. Here, we hypothesized that identifying microbial hosts capable of metabolizing a broader range of nutrients could improve fermentation efficiency. Through whole-genome sequencing, we identified that D. yunweiensis KCTC3955 possesses multiple nutrient transporters and is capable of efficiently utilizing glycerol and various nitrogen sources for carotenoid production. Using one-factor-at-a-time and response surface methodologies, we optimized conditions with glycerol, achieving a 4.45-fold increase in carotenoid yield. Notably, key biosynthetic genes (dxr, idi, ispF, ispH, and cruF) were highly up-regulated under mixed nutrient conditions. Fed-batch fermentation with mixed renewable resources such as glycerol and corn steep liquor reached 23.22 mg/L carotenoid production and 15.48 mg/L/day productivity after 36 h, representing over 11- and 15-fold improvements compared to non-optimized conditions. These results highlight D. yunweiensis KCTC3955 as a strong candidate for carotenoid production from mixed renewable substrates

气候变化对环境的影响凸显了使用低成本原料的可持续生物工艺的必要性。微生物发酵提供了一种从可再生资源中生产增值化合物的环保方法。Deinoxanthin是一种独特的类胡萝卜素色素，由耐辐射细菌Deinococcus产生，在制药和食品工业中有应用。然而，大多数微生物优先利用葡萄糖作为主要的碳源，限制了它们有效发酵副产物或废物来源资源的能力。在这里，我们假设鉴定能够代谢更广泛营养物质的微生物宿主可以提高发酵效率。通过全基因组测序，我们发现D. yunweiensis KCTC3955具有多种营养转运蛋白，能够有效利用甘油和各种氮源生产类胡萝卜素。利用单因素-一次法和响应面法，我们优化了甘油的条件，使类胡萝卜素的产量提高了4.45倍。值得注意的是，在混合营养条件下，关键的生物合成基因（dxr、idi、ispF、ispH和cruF）高度上调。混合可再生资源（如甘油和玉米浸泡液）的补料分批发酵在36 h后，类胡萝卜素的产量达到23.22 mg/L，产量达到15.48 mg/L/d，比未优化的条件分别提高了11倍和15倍。这些结果表明，D. yunweiensis KCTC3955是混合可再生基质生产类胡萝卜素的强有力的候选者

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引用次数: 0

Recent advances in gold and zinc oxide nanoparticles: Antibiofilm action, mechanisms beyond ROS generation, and in vivo efficacy 金和氧化锌纳米颗粒的最新进展：抗生物膜作用、ROS生成机制和体内疗效

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-13 DOI: 10.1016/j.micres.2026.128441

Prasanga M. Kumarage , Tasbiha Gul , Nicholas J. Green , Samuel J.T. Wardell , M. Azam Ali , Minati Choudhury , Daniel Pletzer

Gold (Au) and zinc oxide (ZnO) nanoparticles (AuNPs/ZnONPs, respectively) are well-established antimicrobial nanomaterials with broad-spectrum activity and multifaceted mechanisms of action. This review highlights recent advances, focusing on their antibiofilm activity, novel antimicrobial mechanisms, and therapeutic potential in in vivo infection models. Beyond traditional antibacterial effects, these nanoparticles exhibit potent antibiofilm activity and disrupt multiple cellular targets, including cell wall biosynthesis, membrane transport and efflux pumps, energy metabolism, biofilm formation, quorum sensing pathways, and DNA replication and repair, thereby targeting microorganisms on several fronts simultaneously. In vivo studies, particularly biofilm-relevant infection models, remain comparatively limited; however, available evidence indicates that AuNPs/ZnONPs can reduce bacterial burden, promote wound healing, and improve survival, positioning them as promising candidates for next-generation therapeutics. However, despite promising outcomes, challenges such as nanoparticle cytotoxicity, stability, and delivery efficiency remain significant hurdles to clinical translation. Careful optimization of nanoparticle physicochemical properties, along with the development of advanced functionalization and targeting strategies, will be crucial for enhancing the therapeutic index and safety. Moreover, combining these nanoparticles with existing antibiotics and leveraging computational tools, including artificial intelligence, could accelerate the design of next-generation nanotherapeutics.

金（Au）和氧化锌（ZnO）纳米颗粒（AuNPs/ZnONPs）是公认的具有广谱活性和多方面作用机制的抗菌纳米材料。本文综述了近年来的研究进展，重点是它们的抗生物膜活性、新的抗菌机制和体内感染模型的治疗潜力。除了传统的抗菌作用外，这些纳米颗粒还表现出强大的抗生物膜活性，并破坏多种细胞靶标，包括细胞壁生物合成、膜运输和外排泵、能量代谢、生物膜形成、群体感应途径以及DNA复制和修复，从而同时针对多个方面的微生物。体内研究，特别是与生物膜相关的感染模型，仍然相对有限；然而，现有证据表明，AuNPs/ZnONPs可以减少细菌负担，促进伤口愈合，提高生存率，使其成为下一代治疗药物的有希望的候选者。然而，尽管结果令人鼓舞，但纳米颗粒的细胞毒性、稳定性和递送效率等挑战仍然是临床转化的重大障碍。精心优化纳米颗粒的物理化学性质，以及先进的功能化和靶向策略的发展，对于提高治疗指数和安全性至关重要。此外，将这些纳米颗粒与现有抗生素结合起来，并利用包括人工智能在内的计算工具，可以加速下一代纳米疗法的设计。

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引用次数: 0

Automated high-throughput microscopy screening unveiled new Listeria monocytogenes genes involved in cell infection 自动化高通量显微镜筛选揭示了新的单核细胞增生李斯特菌基因参与细胞感染

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-13 DOI: 10.1016/j.micres.2026.128442

Ângela Alves , Diana Meireles , Chiara Suriano , Ricardo Monteiro , Rute Oliveira , Beatriz G. Bernardes , Sandra Sousa , Rita Pombinho , Didier Cabanes

To uncover novel genetic factors required for Listeria monocytogenes cell infection, we developed an automated high-throughput microscopy screening pipeline that integrates GFP-expressing bacteria with machine learning-based image analysis. Using this approach, we screened a mariner transposon library comprising 4224 L. monocytogenes EGDe mutants and identified 58 with significantly reduced numbers of intracellular bacteria. Sequencing revealed 24 unique insertion sites corresponding to 14 genes, including previously known virulence factors and nine novel candidates not previously implicated in cell infection. These genes encode the protease chaperone ClpX, the ferric uptake regulator Fur, the sensor histidine kinase LisK, the peptide chain release factor 2 PrfB, proteins involved in proline and purine biosynthesis (ProAB, PurAB), and Lmo2217, a protein of unknown function. Among these, the targeted deletion of the adenylosuccinate synthetase gene, purA, resulted in impaired growth in minimal medium, severely reduced proliferation in epithelial and macrophage cell lines, and attenuated virulence in mice. Unexpectedly, PurA was also essential for bacterial internalization into cells. Supplementation with AMP or adenine, but not ATP, rescued the invasion capacity of the ΔpurA mutant. Mechanistically, purA deletion induced a reduction in the levels of surface-associated GAPDH, a putative plasminogen-binding protein, likely contributing to the observed invasion defect. Overall, these findings highlight the power of automated high-throughput microscopy screening to dissect host–pathogen interactions, identify novel L. monocytogenes genes required for cell infection, and uncover an unexpected role for PurA in maintaining GAPDH surface localization and promoting bacterial entry into host cells.

为了揭示单核增生李斯特菌细胞感染所需的新遗传因素，我们开发了一种自动化的高通量显微镜筛选管道，该管道将表达gfp的细菌与基于机器学习的图像分析相结合。利用这种方法，我们筛选了一个包含4224 L的水手转座子文库。单核细胞增生EGDe突变，鉴定出58个细胞内细菌数量显著减少。测序显示了14个基因对应的24个独特的插入位点，包括先前已知的毒力因子和9个以前未涉及细胞感染的新候选基因。这些基因编码蛋白酶伴侣蛋白ClpX，铁摄取调节因子Fur，传感器组氨酸激酶LisK，肽链释放因子2 PrfB，参与脯氨酸和嘌呤生物合成的蛋白质（ProAB, PurAB）和Lmo2217，一种功能未知的蛋白质。其中，腺苷琥珀酸合成酶基因purA的靶向缺失导致在微量培养基中生长受损，上皮细胞和巨噬细胞的增殖严重减少，小鼠的毒力减弱。出乎意料的是，PurA对于细菌内化到细胞中也是必不可少的。补充AMP或腺嘌呤，而不是ATP，恢复了ΔpurA突变体的入侵能力。从机制上讲，purA缺失导致表面相关GAPDH（一种假定的纤溶酶原结合蛋白）水平降低，可能导致观察到的侵袭缺陷。总的来说，这些发现突出了自动化高通量显微镜筛选的力量，以解剖宿主-病原体相互作用，鉴定细胞感染所需的新的单核细胞增生L.菌基因，并揭示PurA在维持GAPDH表面定位和促进细菌进入宿主细胞中的意想不到的作用。

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引用次数: 0

Endophytic fungus-induced phenazine-1-carboxylic acid production in Pseudomonas aeruginosa enhances biocontrol of rice spikelet rot disease 内生真菌诱导铜绿假单胞菌产非那嗪-1-羧酸增强水稻穗腐病的生物防治作用

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2026-01-10 DOI: 10.1016/j.micres.2026.128439

Shi-Yi Huang , Zi-Han Zhao , Jia-Yan Xu , Yaseen Ullah , Yan-Jun Fei , Xiang-Yu Zhang , Xiao-Han Wu , Hui-Jun Jiang , Kai Sun , Xin-Yue Xu , Yong Zhang , Wei Zhang , Chuan-Chao Dai

Rice spikelet rot disease (RSRD) is a late-stage disease that affects rice spikes, leading to grain discoloration, deformation, and a reduced seed-setting rate. Recent studies suggest that the endophytic fungus Phomopsis liquidambaris plays a crucial role in reshaping the microbial community within rice spikes, promoting the enrichment of functionally active microorganisms with potent antagonistic properties, such as Pseudomonas aeruginosa. These beneficial microbes can effectively suppress pathogen infection, thus mitigating the impact of RSRD. Despite these findings, the interaction between Ph. liquidambaris and the key antagonistic microorganism P. aeruginosa remains unclear. In this study, we found that Ph. liquidambaris and P. aeruginosa acted synergistically to reduce the RSRD incidence, disease severity, and grain fumonisin content by 56.15, 44.44, and 23.65 %, respectively. To further investigate the underlying mechanism, we conducted coculture experiments, which revealed that Ph. liquidambaris stimulated P. aeruginosa to increase the production of phenazine-1-carboxylic acid (PCA), a key antimicrobial compound. PCA significantly inhibited the growth of Fusarium proliferatum and suppressed fumonisin biosynthesis. Pot experiments further confirmed its efficacy in preventing and controlling RSRD. Overall, this study demonstrated that fungalbacterial interactions stimulate the production of antimicrobial compounds, offering new insights into their potential for pathogen suppression and plant disease control.

水稻穗腐病（RSRD）是一种影响水稻穗的晚期疾病，导致籽粒变色、变形和结实率降低。最近的研究表明，内生真菌Phomopsis liquidambaris在重塑水稻穗内微生物群落，促进具有强拮抗特性的功能活性微生物（如铜绿假单胞菌）的富集方面起着至关重要的作用。这些有益微生物能够有效抑制病原菌感染，从而减轻RSRD的影响。尽管有这些发现，Ph. liquidambaris与关键拮抗微生物P. aeruginosa之间的相互作用仍不清楚。在本研究中，我们发现Ph. liquidambaris和P. aeruginosa协同作用，分别降低了56.15%、44.44%和23.65% %的RSRD发病率、疾病严重程度和谷物伏马菌素含量。为了进一步研究其潜在机制，我们进行了共培养实验，发现Ph. liquidambaris刺激P. aeruginosa增加了关键抗菌化合物phenazine-1-羧酸（PCA）的产量。PCA显著抑制了增生镰刀菌的生长，抑制了伏马菌素的合成。盆栽试验进一步证实了其防治RSRD的有效性。总的来说，这项研究表明，真菌与细菌的相互作用刺激了抗菌化合物的产生，为它们在抑制病原体和植物疾病控制方面的潜力提供了新的见解。

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引用次数: 0