Applied and Environmental Microbiology最新文献

{"title":"The role of <i>Pantoea stewartii</i> subsp. <i>stewartii</i> leucine-responsive regulatory protein (Lrp) during maize xylem growth.","authors":"Wilson M Farthing, Abigail M Heimbach, Ann M Stevens","doi":"10.1128/aem.00853-25","DOIUrl":"https://doi.org/10.1128/aem.00853-25","url":null,"abstract":"<p><p>The bacterium <i>Pantoea stewartii</i> subsp. <i>stewartii</i> (<i>Pss</i>) causes Stewart's wilt disease in maize. <i>Pss</i> is introduced into maize via the corn flea beetle vector, <i>Chaetocnema pulicaria</i>, when beetle feces enter wounds created during feeding. The infection begins in the apoplast of the leaf where <i>Pss</i> causes leaf blight. Subsequently, the bacteria move to the xylem and form a biofilm, preventing water transport. This causes wilting and leads to necrosis, consequently affecting both crop yield and survival. A previous Tn-Seq experiment identified genes essential for <i>Pss in planta</i> survival. One essential gene, <i>lrp</i>, encodes the global transcription factor leucine-responsive regulatory protein (Lrp). The Lrp protein family is found across many bacterial and archaeal species where it regulates multiple critical physiological functions. In <i>Pss</i>, Lrp is known to positively control motility and capsule production, which are important for the <i>in planta</i> lifestyle and virulence of <i>Pss</i>. In this study, the genes within the <i>Pss</i> Lrp regulon were defined through bioinformatic analyses of RNA-Seq data that measured differential gene expression between wild-type <i>Pss</i> and a <i>∆lrp</i> strain grown <i>in planta</i>. Lrp was found to regulate genes involved in capsule biosynthesis and nitrogen-associated assimilation and metabolism. Biolog plates were subsequently used to link the regulatory role of Lrp with regard to <i>Pss</i> metabolism by examining the capacity of <i>Pss</i> to grow using sole carbon or nitrogen sources <i>in vitro</i>. Collectively, this work has provided insights into how <i>Pss</i> recognizes and exploits the maize xylem environment.IMPORTANCEThe bacterium <i>Pantoea stewartii</i> subsp. <i>stewartii</i> (<i>Pss</i>) causes Stewart's wilt disease in maize when it forms a biofilm in the xylem that prevents water flow. Little is known about how <i>Pss</i> is able to colonize and grow within the maize xylem. Previous work identified the Lrp regulatory protein as being important for the survival of the bacterium inside maize. This study determined the genes whose transcription is under Lrp control and predicted the physiological functions associated with those genes to learn more about the bacterial growth inside the plant. The ability to transport and metabolize organic compounds containing nitrogen and the ability to produce capsule were found to be regulated by Lrp. Additional laboratory experiments demonstrated that Lrp also controls the metabolism of certain sole carbon and nitrogen sources. Together, these findings provide new insights into how Lrp enables <i>Pss</i> to respond to nutrient availability in the maize xylem environment.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0085325"},"PeriodicalIF":3.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144224084","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":"Correction for Van Fossen et al., \"Profiling sorghum-microbe interactions with a specialized photoaffinity probe identifies key sorgoleone binders in <i>Acinetobacter pittii</i>\".","authors":"Elise M Van Fossen, Jared O Kroll, Lindsey N Anderson, Andrew D McNaughton, Daisy Herrera, Yasuhiro Oda, Andrew J Wilson, William C Nelson, Neeraj Kumar, Andrew R Frank, Joshua R Elmore, Pubudu Handakumbura, Vivian S Lin, Robert G Egbert","doi":"10.1128/aem.00810-25","DOIUrl":"https://doi.org/10.1128/aem.00810-25","url":null,"abstract":"","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0081025"},"PeriodicalIF":3.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144224081","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":"Diverse <i>Sulfuriferula</i> spp. from sulfide mineral weathering environments oxidize ferrous iron and reduced inorganic sulfur compounds.","authors":"Kathryn K Hobart, Gabriel M Walker, Joshua M Feinberg, Jake V Bailey, Daniel S Jones","doi":"10.1128/aem.00216-25","DOIUrl":"https://doi.org/10.1128/aem.00216-25","url":null,"abstract":"<p><p>Microorganisms are important catalysts for the oxidation of reduced inorganic sulfur compounds. One environmentally important source of reduced sulfur is metal sulfide minerals that occur in economic mineral deposits and mine waste. Previous research found that <i>Sulfuriferula</i> spp. were abundant and active in long-term weathering experiments with simulated waste rock and tailings from the Duluth Complex, Northern Minnesota. We, therefore, isolated several strains of <i>Sulfuriferula</i> spp. from these long-term experiments and characterized their metabolic and genomic properties to provide insight into microbe-mineral interactions and the microbial biogeochemistry in these and other moderately acidic to circumneutral environments. The <i>Sulfuriferula</i> strains are all obligate chemolithoautotrophs capable of oxidizing inorganic sulfur compounds and ferrous iron. The strains grew over different pH ranges, but all grew between pH 4.5 and 7, matching the weathering conditions of the Duluth Complex rocks. All strains grew on the iron-sulfide mineral pyrrhotite (Fe_{1 - <i>x</i>}S, 0 < <i>x</i> < 0.125) as the sole energy source, as well as hydrogen sulfide and thiosulfate, which are products of sulfide mineral breakdown. Despite their metabolic similarities, each strain encodes a distinct pathway for the oxidation of reduced inorganic sulfur compounds as well as differences in nitrogen metabolism that reveal diverse genomic capabilities among the group. Our results show that <i>Sulfuriferula</i> spp. are primary producers that likely play a role in sulfide mineral breakdown in moderately acidic to circumneutral mine waste, and the metabolic diversity within the genus may explain their success in sulfide mineral-rich and other sulfidic environments.</p><p><strong>Importance: </strong>Metal sulfide minerals, such as pyrite and pyrrhotite, are one of the main sources of reduced sulfur in the global sulfur cycle. The chemolithotrophic microorganisms that break down these minerals in natural and engineered settings are catalysts for biogeochemical sulfur cycling and have important applications in biotechnological processes such as biomining and bioremediation. <i>Sulfuriferula</i> is a recently described genus of sulfur-oxidizing bacteria that are abundant primary producers in diverse terrestrial environments, including waste rock and tailings from metal mining operations. In this study, we explored the genomic and metabolic properties of new isolates from this genus, and the implications for their ecophysiology and biotechnological potential in ore and waste from economic mineral deposits.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0021625"},"PeriodicalIF":3.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144224082","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":"Donor-derived microbial engraftment and gut microbiota shifts associated with weight loss following fecal microbiota transplantation.","authors":"Yuting Ruan, Tongxi Zhu, Rui Yang, Fugui Su, Chiying An, Zhuping Hu, Xiaoli Li, Yue Li, Peizhao Chen, Xueni Shao, Junjie Qin, Hong Chen, Rongping Chen","doi":"10.1128/aem.00120-25","DOIUrl":"https://doi.org/10.1128/aem.00120-25","url":null,"abstract":"<p><p>Fecal microbiota transplantation (FMT) is a promising treatment for microbiota dysbiosis and may provide metabolic benefits for obesity. However, its mechanisms and variability in clinical outcomes remain poorly understood. This 12-week multicenter, single-arm study evaluated the efficacy of FMT for weight loss and explored the role of donor-derived microbial engraftment and functional shifts in mediating weight loss among overweight and obese individuals. Twenty-three participants (body mass index ≥24 kg/m²) without diabetes received three biweekly FMT sessions via a nasojejunal tube. Fecal samples from participants and donors were analyzed using metagenomic sequencing. By week 12, 52% of participants were classified as responders, achieving significant weight loss of ≥5% from baseline, with an average weight loss of 7.98 ± 2.69 kg (<i>P</i> < 0.001). In contrast, non-responders lost 2.90 ± 1.89 kg (<i>P</i> < 0.001). Responders exhibited a significantly higher proportion of donor-derived microbial strains post-FMT compared to non-responders (37.8% vs 15.2%, <i>P</i> = 0.020). Notably, key taxa, including <i>Phascolarctobacterium</i> (<i>P</i> = 0.034) and <i>Acidaminococcaceae</i> (<i>P</i> = 0.012), increased significantly in abundance in responders post-FMT, indicating successful microbial engraftment as a critical determinant of therapeutic success. These findings suggest that FMT is a viable intervention for weight loss in obese individuals. Successful donor-derived microbial engraftment strongly correlates with weight loss efficacy, highlighting the potential of microbiota-targeted therapies in obesity management and providing insights into the mechanisms underlying FMT outcomes.IMPORTANCEPrior research indicates that fecal microbiota transplantation (FMT) is a promising treatment for diseases related to microbiota imbalance, potentially providing metabolic benefits for obesity. However, the specific role of donor-derived microbial engraftment in driving clinical efficacy has remained unclear. In this study, we evaluated the efficacy of FMT in promoting weight loss and explored the role of donor-derived bacterial strains in this process. Our findings demonstrate that the successful engraftment of specific donor-derived taxa, such as <i>Phascolarctobacterium</i> and <i>Acidaminococcaceae</i>, is strongly associated with significant weight loss. This highlights the critical interplay between donor microbiota and recipient gut environment. These findings underscore the potential of microbiota-targeted therapies as a novel strategy for obesity management.CLINICAL TRIALSThis study is registered with the Chinese Clinical Trial Registry as ChiCTR1900024760.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0012025"},"PeriodicalIF":3.9,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214734","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":"Xylanolytic metabolism is regulated by coordination of transcription factors XynR and XylR in extremely thermophilic <i>Caldicellulosiruptorales</i>.","authors":"Mohamad J H Manesh, James R Crosby, Tunyaboon Laemthong, Ryan G Bing, Stefanie H Chen, Jason Vailionis, Tania N N Tanwee, Ying Zhang, Dmitry A Rodionov, Michael W W Adams, Robert M Kelly","doi":"10.1128/aem.00516-25","DOIUrl":"https://doi.org/10.1128/aem.00516-25","url":null,"abstract":"<p><p>Global transcription factors (TFs) control metabolic processes in bacteria to efficiently utilize available carbon. The order <i>Caldicellulosiruptorales</i> has drawn interest due to the ability of its members to degrade components of lignocellulosic biomass. Regulatory reconstruction of <i>Anaerocellum (f. Caldicellulosiruptor) bescii</i> identified two major global transcription factors for xylan utilization, XynR and XylR, and the corresponding putative transcription factor binding sites. Recombinant versions of XynR (LacI family) and XylR (ROK family) were subjected to fluorescence polarization (FP) and biolayer interferometry (BLI) analysis to confirm the predicted binding sites. Four XynR sites and two XylR sites were validated, accounting for 20 of 26 genes regulated by XynR and six of seven genes regulated by XylR. Bioinformatic analysis of the individual genes controlled by the two regulators showed an inter-dependent scheme for xylan conversion; the transport of xylooligosaccharides (XOS) is dependent on XylR, while enzymes responsible for hydrolysis are controlled by both regulators. For xylose catabolism by the xylose isomerase-xylulose kinase pathway, regulation is also split, with XylR controlling xylose isomerase and XynR controlling xylokinase. The XynR/XylR regulator pair within <i>A. bescii</i> is conserved in all sequenced species of <i>Caldicellulosiruptorales</i>, suggesting similarities in regulating linear xylan conversion. In other xylanolytic thermophiles, XylR homologs control xylan degradation, compared to just 6 out of 26 genes for <i>A. bescii</i>. These results show that two separate regulatory schemes (dual repression) are coordinated by <i>A. bescii</i> to effectively regulate the hemicellulose inventory and xylan catabolism.IMPORTANCETo take full advantage of extreme thermophiles as platform metabolic engineering microorganisms, the tools for genetic manipulation must be further developed, and strategies that exploit a better understanding of metabolic regulation need to be discerned. <i>Anaerocellum bescii</i>, the most studied of the extremely thermophilic fermentative anaerobic bacteria that can utilize microcrystalline cellulose, can degrade microcrystalline cellulose and hemicellulose and has been metabolically engineered to convert the resulting sugars to products such as ethanol and acetone. For xylan, in particular, two major global transcription factors (TFs), XynR and XylR, play a role in sugar metabolism, although their predicted regulatory interdependence from bioinformatics analysis has not been elucidated experimentally. Here, fluorescence polarization (FP) and biolayer interferometry (BLI) were used to explore this issue to support metabolic engineering efforts aimed at improving carbohydrate processing to industrial chemicals.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0051625"},"PeriodicalIF":3.9,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214736","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":"Crucial roles of intracellular cyclic di-GMP in impacting the genes important for extracellular electron transfer by <i>Geobacter metallireducens</i>.","authors":"Yongguang Jiang, Lin Sun, Lingyu Hou, Yidan Hu, Zhou Jiang, Yiran Dong, Hao Song, Liang Shi","doi":"10.1128/aem.00727-25","DOIUrl":"https://doi.org/10.1128/aem.00727-25","url":null,"abstract":"<p><p>To investigate the roles of intracellular c-di-GMP in bacterial extracellular electron transfer (EET), three <i>Geobacter metallireducens</i> strains with high (Gme-H), intermediate (Gme-C), and low (Gme-L) intracellular levels of c-di-GMP were constructed via the synthetic biology approach. Compared to Gme-C, Gme-H showed similar Fe(III) reduction rates, formed thicker biofilms on conductive and nonconductive surfaces, and produced more electricity, but showed delayed ability for electricity production. Gme-L formed thinner biofilms on nonconductive surfaces and reduced Fe(III)-citrate faster, but showed slower reduction of ferrihydrite in comparison to Gme-C. Although it produced electricity much faster, Gme-L produced less electricity and formed slightly less amounts of biofilms on anodes, as compared to Gme-C. The mRNA levels of multiple genes encoding <i>c</i>-type cytochromes (<i>c</i>-Cyts) and extracellular pilin protein PilA-N were differentially regulated in Gme-L or Gme-H in comparison to that in Gme-C. Expressions of the genes for PilA-N and extracellular <i>c</i>-Cyt Gmet2896 were increased by high c-di-GMP. Low c-di-GMP increased the gene expressions of the porin-cytochromes in the outer membrane. Further investigation also identified new c-di-GMP-regulated genes directly involved in the EET of <i>G. metallireducens</i>, such as those for the <i>c</i>-Cyts of extracellular Gmet0601, the periplasmic Gmet1703 and Gmet1809 on the cytoplasmic membrane, as deletions of these genes impaired bacterial reductions of extracellular ferrihydrite and anode. Thus, intracellular c-di-GMP impacted multiple genes of <i>G. metallireducens</i> whose protein products might transfer electrons from the cytoplasmic membrane, through the periplasm, across the outer membrane to and in the extracellular environment.IMPORTANCEBis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is ubiquitous in bacterial cells where it regulates a variety of bacterial processes, which range from biofilm formation, bacterial virulence to cell cycle progression. However, its role in regulating bacterial extracellular electron transfer is much less characterized. This investigation shows the crucial roles of intracellular c-di-GMP in impacting the extracellular electron transfer of the Gram-negative bacterium <i>Geobacter metallireducens</i>. The gene expressions of the multiheme <i>c</i>-type cytochromes in the bacterial cytoplasmic membrane, periplasm, outer membrane, and extracellular environment, as well as the gene expression of extracellular pilin protein PilA-N, are all impacted by c-di-GMP. Although how it impacts the expression of these genes is currently unclear, c-di-GMP affects the entire extracellular electron transfer process of <i>G. metallireducens</i> from the cytoplasmic membrane, through the periplasm and across the outer membrane to and in the extracellular environment.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0072725"},"PeriodicalIF":3.9,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214733","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":"Proline Stickland fermentation supports <i>C. difficile</i> spore maturation.","authors":"Zavier A Carter, Christopher E O'Brien, Shonna M McBride","doi":"10.1128/aem.00551-25","DOIUrl":"https://doi.org/10.1128/aem.00551-25","url":null,"abstract":"<p><p><i>Clostridioides difficile</i> is an anaerobic pathogen that thrives in the metabolically diverse intestinal environment. <i>C. difficile</i> is readily transmitted due to its transformation into a dormant spore form that is highly resistant to heat and disinfectants. Nutrient limitation is a key driver of spore formation; however, few metabolites have been directly shown to influence the regulation of <i>C. difficile</i> sporulation. A distinct aspect of <i>C. difficile</i> biology is the fermentation of amino acids through Stickland metabolism pathways, which are critical sources of energy for this pathogen. We hypothesized that as a preferred energy source, the amino acid proline may serve as a signal that regulates the initiation of sporulation or the development of spores. Using mutants in the proline reductase gene, <i>prdA</i>, and the proline-dependent regulator, <i>prdR,</i> we examined the impact of proline on <i>C. difficile</i> physiology and differentiation. Our results demonstrate that proline reductase is important for the development of mature spores and that excess proline can repress <i>C. difficile</i> sporulation through PrdR regulation. Furthermore, we discovered that the end product of proline reduction, 5-aminovalerate, can support the growth of <i>C. difficile</i> through an unidentified, PrdR-dependent mechanism.IMPORTANCE<i>C. difficile</i> is an anaerobic intestinal pathogen that disseminates in the environment as dormant, resilient spores. Nutrient limitation is known to stimulate spore production, but the contribution of specific nutrients to sporulation is poorly understood. In this study, we examined the contribution of proline and proline fermentation to spore formation. Our results demonstrate the effect of proline fermentation on spore quality and the importance of the proline reductase pathway on spore maturation.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0055125"},"PeriodicalIF":3.9,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214735","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":"Function and regulation of <i>pob</i> genes for 4-hydroxybenzoate catabolism in <i>Agrobacterium tumefaciens</i>.","authors":"Nan Xu, Wanyu Wang, Shuang Cheng, Jiaojiao Zuo, Minliang Guo","doi":"10.1128/aem.00255-25","DOIUrl":"https://doi.org/10.1128/aem.00255-25","url":null,"abstract":"<p><p><i>Agrobacterium tumefaciens</i> is a pathogen that causes tumors in plants. Phenolic acids present in the soil and rhizosphere may affect the interaction between <i>A. tumefaciens</i> and plants. An important pathway for microorganisms to degrade phenolic acids is the β-ketoadipate pathway, which has been annotated in the genome of <i>A. tumefaciens</i>. The ability of the PobA (atu4544) enzyme to catalyze the conversion of 4-hydroxybenzoate to protocatechuate was essential for cell growth using 4-hydroxybenzoate as the sole carbon source. The <i>pobA</i> gene is located upstream of <i>atu4545</i>, encoding an AraC transcription factor (PobR). Strains with deleted or supplemented <i>atu4545</i> exhibited similar growth characteristics on common and phenolic acid-containing carbon sources as strains with deleted or supplemented <i>atu4544</i>. Strains with a <i>pobA::lacZ</i> reporter fusion showed that PobR induced <i>pobA</i> expression. In addition, the use of a <i>pobR::lacZ</i> reporter fusion showed that PobR represses its expression. Electromobility shift assay revealed that the PobR regulator can bind specifically to DNA. The binding site was identified as CGTGCGATGGTGGATT. Deletions of <i>atu4544</i> (<i>pobA</i>) and <i>atu4545</i> (<i>pobR</i>) decreased <i>A. tumefaciens</i> pathogenicity by infecting carrot roots and kalanchoe leaves, with no effect on <i>virB</i> genes, and decreased bacterial biomass when phenolic acids were present. The collective findings demonstrate how transcriptional regulation by <i>A. tumefaciens</i> controls the metabolism of 4-hydroxybenzoate and imply that PobA and PobR aid in bacterial survival during host plant infection.IMPORTANCE<i>Agrobacterium tumefaciens</i> is a widely distributed environmental bacterium and a recognized phytopathogen. Phenolic acids influence the relationship between <i>A. tumefaciens</i> and plants. One of the most important phenolic acids found in soil is 4-hydroxybenzoate, which is generated by plants. Mutants defective in the <i>atu4544</i> and <i>atu4545</i> genes inhibit <i>A. tumefaciens</i> tumor development. The <i>atu4544</i>-encoded enzyme, PobA, can metabolize 4-hydroxybenzoate, and the expression of its gene is positively regulated by the transcription factor encoded by <i>atu4545</i>. The <i>atu4545</i> gene is subject to negative autoregulation. The binding site of atu4545 is CGTGCGATGGTCGGATT. Dual regulation of regulators for phenolic acid catabolism may aid in the maintenance of appropriate quantities of phenolic compounds. These results clarify the pathogenic mechanisms of <i>A. tumefaciens</i> and broaden the understanding of the metabolic control mechanisms of phenolic chemicals.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0025525"},"PeriodicalIF":3.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207421","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":"<i>Aeromonas</i> spp. as a fast-growing high-performance chassis for protein production.","authors":"Ming-Xuan Tang, Peng-Fei Meng, Ruo-Lin Huang, Xin Zheng, Chen-Chen Liang, Xuepiao Pu, Chen Wang, Ying Zhao, Yi-Qiu Zhang, Jia-Xin Liang, Yu-Xi Yan, Yanyu Xiao, Ying An, Xiaoye Liang, Yi Song, Jiuxin Qu, Bo Yu, Yu Xia, Tao Dong","doi":"10.1128/aem.00780-25","DOIUrl":"https://doi.org/10.1128/aem.00780-25","url":null,"abstract":"<p><p>Recombinant protein production is crucial for biotechnology and industrial processes. While <i>Escherichia coli</i> and other bacterial systems are effective, alternative systems can complement their limitations in specific applications. We introduce AMAX, a fast-growing high-performance bacterial chassis with target protein yields comprising 60-70% of total protein content. AMAX is compatible with common protein expression vectors, exhibits a growth rate comparable to <i>Vibrio natriegens</i>, and can adapt to diverse conditions, including co-production with <i>E. coli</i>, freshwater to seawater salinity, and contaminant phages. We also demonstrate the versatility of AMAX in producing several commercially valuable enzymes at high yield and purity. Transcriptomic and proteomic analyses highlight its robust regulatory networks and potential for outer membrane vesicle (OMV)-mediated cargo delivery. Safety evaluation using multiple eukaryotic models indicates it is nontoxic. These results demonstrate AMAX as a valuable tool for recombinant protein production.</p><p><strong>Importance: </strong>AMAX complements current systems by addressing challenges such as phage contamination and high GC-content protein expression, while offering rapid growth, high protein yields, and adaptability to saline environments. Its favorable biosafety profile and potential for OMV-based protein delivery further enhance its application, making it a versatile platform for sustainable and efficient bioproduction.</p>","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0078025"},"PeriodicalIF":3.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207419","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":"Erratum for Ivanova et al., \"Large-scale phenotypic and genomic analysis of <i>Listeria monocytogenes</i> reveals diversity in the sensitivity to quaternary ammonium compounds but not to peracetic acid\".","authors":"Mirena Ivanova, Martin Laage Kragh, Judit Szarvas, Elif Seyda Tosun, Natacha Friis Holmud, Alexander Gmeiner, Corinne Amar, Claudia Guldimann, TuAnh N Huynh, Renáta Karpíšková, Carmen Rota, Diego Gomez, Eurydice Aboagye, Andrea Etter, Patrizia Centorame, Marina Torresi, Maria Elisabetta De Angelis, Francesco Pomilio, Anders Hauge Okholm, Yinghua Xiao, Sylvia Kleta, Stefanie Lüth, Ariane Pietzka, Jovana Kovacevic, Franco Pagotto, Kathrin Rychli, Irena Zdovc, Bojan Papić, Even Heir, Solveig Langsrud, Trond Møretrø, Phillip Brown, Sophia Kathariou, Roger Stephan, Taurai Tasara, Paw Dalgaard, Patrick Murigu Kamau Njage, Annette Fagerlund, Frank Aarestrup, Lisbeth Truelstrup Hansen, Pimlapas Leekitcharoenphon","doi":"10.1128/aem.00956-25","DOIUrl":"https://doi.org/10.1128/aem.00956-25","url":null,"abstract":"","PeriodicalId":8002,"journal":{"name":"Applied and Environmental Microbiology","volume":" ","pages":"e0095625"},"PeriodicalIF":3.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207420","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}