Journal of Bacteriology最新文献

{"title":"Iron-based microbial interactions: the role of iron metabolism in the cheese ecosystem.","authors":"Rina Mekuli, Mahtab Shoukat, Eric Dugat-Bony, Pascal Bonnarme, Sophie Landaud, Dominique Swennen, Vincent Hervé","doi":"10.1128/jb.00539-24","DOIUrl":"https://doi.org/10.1128/jb.00539-24","url":null,"abstract":"<p><p>Iron is involved in various microbial metabolisms and interactions and is an essential micronutrient for most microorganisms. This review focuses on the cheese ecosystem, in which iron is sparse (median concentration of 2.9 mg/kg based on a literature survey) and of limited bioavailability due to the presence of various metal-binding agents in the cheese matrix. Cheese microorganisms overcome this low bioavailability of iron by producing and/or importing ferric iron-specific chelators called siderophores. We introduce these siderophores and their specific transporters, which play a key role in ecological interactions and microbial metabolism. We discuss the impact of iron on all the major taxa (fungi, bacteria, and viruses) and functional groups (starters, ripening microorganisms, and pathogens) present and interacting in cheese, from the community to individual levels. We describe the ways in which cheese-ripening microorganisms use iron and the effects of iron limitation on major metabolic pathways, including the tricarboxylic acid (TCA) cycle and amino-acid biosynthesis. The cheese ecosystem is a relevant <i>in situ</i> model for improving our understanding of iron biochemistry and its putative role in microbe-microbe interactions. Yet, this review highlights critical gaps in our understanding of iron's role in cheese from fundamental ecological and biochemical perspectives to applied microbiology, with broader implications for the quality, safety, and organoleptic properties of cheese.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0053924"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The TerC family metal chaperone MeeY enables surfactin export in <i>Bacillus subtilis</i>.","authors":"Bixi He, Ankita J Sachla, Sadie B Ruesewald, Daniel B Kearns, John D Helmann","doi":"10.1128/jb.00088-25","DOIUrl":"https://doi.org/10.1128/jb.00088-25","url":null,"abstract":"<p><p>TerC family proteins are widely conserved integral membrane proteins with functions related to metal transport. In <i>Bacillus subtilis</i>, the TerC proteins MeeF and MeeY play overlapping roles in the metalation of manganese-requiring membrane and extracellular enzymes. TerC proteins interact with the secretion translocon SecYEG and metalate proteins either during or after protein translocation. Here, we demonstrate that swarming motility is dependent on MeeY. This swarming defect can be complemented extracellularly and is correlated with a loss of surfactin. Surfactin export is mediated by SwrC, an RND family efflux pump previously shown to interact with MeeY in co-immunoprecipitation studies. The amendment of the growth medium with manganese has long been known to enhance surfactin production. We suggest a model in which surfactin export is enhanced by the MeeY-dependent metalation of the surfactin lipopeptide during export.IMPORTANCE<i>Bacillus subtilis</i> produces surfactin, a powerful detergent-like compound that functions in intercellular communication, surface motility, and as a broad-spectrum antimicrobial agent. Production of surfactin, a cyclic lipopeptide, depends on a non-ribosomal peptide synthase followed by export by SwrC, a member of the resistance-nodulation-cell division (RND) family of export proteins. Here, we demonstrate that surfactin production additionally requires MeeY, a TerC family membrane protein that exports manganese ions to support the function of secreted and membrane metalloenzymes. We propose that MeeY interacts with SwrC to facilitate metal binding to the surfactin lipopeptide during export from the cell. These results may explain the long-appreciated role that divalent metal ions play in surfactin production during industrial fermentation.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0008825"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144003846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defining the networks that connect RNase III and RNase J-mediated regulation of primary and specialized metabolism in <i>Streptomyces venezuelae</i>.","authors":"Meghan A D Pepler, Emma L Mulholland, Freddie R Montague, Marie A Elliot","doi":"10.1128/jb.00024-25","DOIUrl":"https://doi.org/10.1128/jb.00024-25","url":null,"abstract":"<p><p>RNA metabolism involves coordinating RNA synthesis with RNA processing and degradation. Ribonucleases play fundamental roles within the cell, contributing to the cleavage, modification, and degradation of RNA molecules, with these actions ensuring appropriate gene regulation and cellular homeostasis. Here, we employed RNA sequencing to explore the impact of RNase III and RNase J on the transcriptome of <i>Streptomyces venezuelae</i>. Differential expression analysis comparing wild-type and RNase mutant strains at distinct developmental stages revealed significant changes in transcript abundance, particularly in pathways related to multicellular development, nutrient acquisition, and specialized metabolism. Both RNase mutants exhibited dysregulation of the BldD regulon, including altered expression of many cyclic-di-GMP-associated enzymes. We also observed precocious chloramphenicol production in these RNase mutants and found that in the RNase III mutant, this was associated with PhoP-mediated regulation. We further found that RNase III directly targeted members of the PhoP regulon, suggesting a link between RNA metabolism and a regulator that bridges primary and specialized metabolism. We connected RNase J function with translation through the observation that RNase J directly targets multiple ribosomal protein transcripts for degradation. These findings establish distinct but complementary roles for RNase III and RNase J in coordinating the gene expression dynamics critical for <i>S. venezuelae</i> development and specialized metabolism.</p><p><strong>Importance: </strong>RNA processing and metabolism are mediated by ribonucleases and are fundamental processes in all cells. In the morphologically complex and metabolically sophisticated <i>Streptomyces</i> bacteria, RNase III and RNase J influence both development and metabolism through poorly understood mechanisms. Here, we show that both ribonucleases are required for the proper expression of the BldD developmental pathway and contribute to the control of chloramphenicol production, with an interesting connection to phosphate regulation for RNase III. Additionally, we show that both RNases have the potential to impact translation through distinct mechanisms and can function cooperatively in degrading specific transcripts. This study advances our understanding of RNases in <i>Streptomyces</i> biology by providing insight into distinct contributions made by these enzymes and the intriguing interplay between them.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0002425"},"PeriodicalIF":2.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The adjacent ATP-binding protein-encoding genes of the <i>Enterococcus faecalis</i> phosphate-specific transport (<i>pst</i>) locus have non-overlapping cellular functions.","authors":"Christopher M Healy, Evelyn A Pham, Keane J Dye, Candace N Rouchon, Biko McMillan, Kristi L Frank","doi":"10.1128/jb.00033-25","DOIUrl":"https://doi.org/10.1128/jb.00033-25","url":null,"abstract":"<p><p>The widely conserved <i>pst-phoU</i> operon encodes a low-velocity, high-affinity, ATP-dependent importer for inorganic phosphate (Pi). The <i>pstB</i> gene encodes the ATPase that powers the import of Pi into the cell. In some Firmicutes, including the gastrointestinal commensal and opportunistic pathogen <i>Enterococcus faecalis</i>, the <i>pst-phoU</i> locus contains adjacent <i>pstB</i> genes. In this work, we compared the functionality of <i>E. faecalis pstB1</i> and <i>pstB2. E. faecalis pstB1</i> and <i>pstB2</i> share sequence similarities with verified PstB ATPases from <i>Escherichia coli</i> and <i>Streptococcus pneumoniae</i> and only share ~60% amino acid identity with each other. Deletion of <i>pstB1</i> was associated with a growth defect in low Pi-containing chemically defined medium (CDM), reduced Pi uptake, and a moderate increase in alkaline phosphatase (AP) activity. Deletion of <i>pstB2</i> fully inhibited growth in CDM regardless of inorganic phosphorus source but did not hinder growth in rich, undefined medium. The Δ<i>pstB2</i> mutant also exhibited a significant increase in AP activity that was associated with extracellular Pi accumulation. Overexpression of <i>pstB2</i> in the <i>pstB1</i> mutant was sufficient to restore growth in low-Pi CDM, Pi uptake, and AP activity, but this was not recapitulated with overexpression of <i>pstB1</i> in the Δ<i>pstB2</i> mutant. Deletion of either <i>pstB</i> paralog increased expression of the tandem paralog, and overexpression of <i>pstB2</i> in Δ<i>pstB2</i> reduced <i>pstB1</i> expression. These results suggest that the <i>E. faecalis pstB2</i>-encoded ATPase is required for Pi import, while the <i>pstB1</i>-encoded ATPase has an accessory role in Pi import that can be duplicated by the presence of excess PstB2.</p><p><strong>Importance: </strong>Phosphate is critical for all microbial life. In many bacteria, inorganic phosphate (Pi) is imported by the high-affinity, low-velocity Pst-PhoU system. The <i>pstB</i> gene encodes the ATPase that powers Pi import. The <i>pst-phoU</i> operon in many Firmicutes, including the human commensal and opportunistic pathogen <i>Enterococcus faecalis</i>, contains adjacent <i>pstB</i> genes, <i>pstB1</i> and <i>pstB2</i>. No studies on the relative biological contributions of tandem <i>pstB</i> paralogs in any microbe have been published. This genetic study indicates that <i>E. faecalis pstB1</i> and <i>pstB2</i> do not have equivalent functions. The <i>pstB2</i> gene encodes an ATPase that is required for Pi import, while the ATPase encoded by <i>pstB1</i> has an accessory role in Pi import that can be duplicated by the presence of excess PstB2.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0003325"},"PeriodicalIF":2.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143985451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colony morphotype variation in <i>Burkholderia:</i> implications for success of applications and therapeutics.","authors":"Pauline M L Coulon, Kirsty Agnoli, Garry S A Myers","doi":"10.1128/jb.00521-24","DOIUrl":"https://doi.org/10.1128/jb.00521-24","url":null,"abstract":"<p><p>The <i>Burkholderia</i> genus includes both environmental and pathogenic isolates known for their phenotypic plasticity and adaptability. <i>Burkholderia</i> spp. are intrinsically resistant to many antibiotics, often requiring prolonged therapies during infection. A key feature of <i>Burkholderia</i> spp. is colony morphotype variation (CMV), which allows for rapid adaptation to environmental changes and influences virulence, antibiotic resistance, and pathogenicity by impacting the expression of key virulence factors such as lipopolysaccharides, extracellular DNA, efflux pumps, and flagella. While alternative treatments, such as vaccines and phage therapies, hold promise, CMV has the potential to undermine their efficacy by modifying essential therapeutic targets. Despite its importance, the prevalence and underlying mechanisms of CMV remain poorly understood, leaving critical gaps in our knowledge that may hinder the development of sustainable solutions for managing <i>Burkholderia</i> infections. Addressing these gaps is crucial not only for improving infection management but also for enabling the safe reuse of <i>Burkholderia</i> in biotechnology, where their plant growth-promoting and bioremediation properties are highly valuable. Our goal is to raise awareness within the scientific community about the significance of CMV in <i>Burkholderia</i>, highlighting the urgent need to uncover the mechanisms driving CMV. A deeper understanding of CMV's role in virulence and resistance is essential to developing robust, long-term therapeutic strategies.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0052124"},"PeriodicalIF":2.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144006767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the gut microbiota's role in obesity: key metabolites, microbial species, and therapeutic insights.","authors":"Majid Iqbal, Qian Yu, Jingqun Tang, Juanjuan Xiang","doi":"10.1128/jb.00479-24","DOIUrl":"https://doi.org/10.1128/jb.00479-24","url":null,"abstract":"<p><p>Obesity, characterized by excessive fat accumulation, stems from an imbalance between energy intake and expenditure, with the gut microbiota playing a crucial role. This review highlights how gut microbiota influences metabolic pathways, inflammation, and adipose tissue regulation in obesity. Specific bacteria and metabolites, such as lipopolysaccharides (LPS) and short-chain fatty acids (SCFAs), modulate gut permeability, inflammation, and energy harvest, impacting obesity development. Certain gut bacteria, including <i>Clostridium XIVb</i>, <i>Dorea</i> spp., <i>Enterobacter cloacae</i>, and <i>Collinsella aerofaciens</i>, promote obesity by increasing energy harvest, gut permeability, and inflammatory response through LPS translocation into the bloodstream. Conversely, beneficial bacteria like <i>Akkermansia muciniphila</i>, <i>Lactobacillus</i> spp., and <i>Bifidobacterium</i> spp. enhance gut barrier integrity, regulate SCFA production, and modulate fasting-induced adipose factor, which collectively support metabolic health by reducing fat storage and inflammation. Metabolites such as SCFAs (acetate, propionate, and butyrate) interact with G-protein coupled receptors to regulate lipid metabolism and promote the browning of white adipose tissue (WAT), thus enhancing thermogenesis and energy expenditure. However, LPS contributes to insulin resistance and fat accumulation, highlighting the dual roles of these microbial metabolites in both supporting and disrupting metabolic function. Therapeutic interventions targeting gut microbiota, such as promoting WAT browning and activating brown adipose tissue (BAT), hold promise for obesity management. However, personalized approaches are necessary due to individual microbiome variability. Further research is essential to translate these insights into microbiota-based clinical therapies.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0047924"},"PeriodicalIF":2.7,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid screening and identification of genes involved in bacterial extracellular membrane vesicle production using a curvature-sensing peptide.","authors":"Hiromu Inoue, Kenichi Kawano, Jun Kawamoto, Takuya Ogawa, Tatsuo Kurihara","doi":"10.1128/jb.00497-24","DOIUrl":"https://doi.org/10.1128/jb.00497-24","url":null,"abstract":"<p><p>Bacteria secrete extracellular membrane vesicles (EMVs). Physiological functions and biotechnological applications of these lipid nanoparticles have been attracting significant attention. However, the details of the molecular basis of EMV biogenesis have not yet been fully elucidated. In our previous work, an N-terminus-substituted FAAV peptide labeled with nitrobenzoxadiazole (NBD; nFAAV5-NBD) was developed. This peptide can sense the curvature of a lipid bilayer and selectively bind to EMVs even in the presence of cells. Here, we applied nFAAV5-NBD to a genome-wide screening of hyper- and hypo-vesiculation transposon mutants of a Gram-negative bacterium, <i>Shewanella vesiculosa</i> HM13, to identify the genes involved in EMV production. We analyzed the transposon insertion sites in hyper- and hypo-vesiculation mutants and identified 16 and six genes, respectively, with a transposon inserted within or near them. Targeted gene-disrupted mutants of the identified genes showed that the lack of putative dipeptidyl carboxypeptidase, glutamate synthase β-subunit, LapG protease, metallohydrolase, RNA polymerase sigma-54 factor, inactive transglutaminase, PepSY domain-containing protein, and Rhs-family protein caused EMV overproduction. On the other hand, disruption of the genes encoding putative phosphoenolpyruvate synthase, d-hexose-6-phosphate epimerase, NAD-specific glutamate dehydrogenase, and sensory box histidine kinase/response regulator decreased EMV production. This study demonstrates the utility of a novel screening method using a curvature-sensing peptide for mutants with altered EMV productivity and provides information on the genes related to EMV production.IMPORTANCEConventional methods for isolation and quantification of extracellular membrane vesicles (EMVs) are generally time-consuming. nFAAV5-NBD can detect EMVs in the culture without separating EMVs from cells. <i>In situ</i> detection of EMVs using this peptide facilitated screening of the genes related to EMV production. We succeeded in identifying various genes associated with EMV production of <i>Shewanella vesiculosa</i> HM13, which would contribute to the elucidation of bacterial EMV formation mechanisms. Additionally, the hyper-vesiculating mutants obtained in this study would be valuable for EMV applications, such as secreting useful substances as EMV cargoes and producing artificially functionalized EMVs.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0049724"},"PeriodicalIF":2.7,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Bacillus subtilis</i> MurJ and Amj Lipid II flippases are not essential for growth.","authors":"Kiera Englehart, Jonathan Dworkin","doi":"10.1128/jb.00078-25","DOIUrl":"https://doi.org/10.1128/jb.00078-25","url":null,"abstract":"<p><p>Identification of the protein that mediates transbilayer transport of the undecaprenyl-pyrophosphate (Und-PP) linked peptidoglycan precursor Lipid II has long been a subject of investigation. Candidates belonging to both the MOP (multidrug/oligosaccharidyl-lipid/polysaccharide) and SEDS (shape, elongation, division and sporulation) families of transmembrane proteins have been proposed, exhibiting characteristics consistent with mediating this process, including genetic essentiality and biochemical activity. While MOP family proteins including MurJ are widely considered to be the primary Lipid II transporter, questions still remain including a role for the SEDS proteins in this process. We and others previously showed that a <i>Bacillus subtilis</i> strain lacking all four MurJ homologs is viable, thereby implicating a separate mode of Lipid II transport across the membrane. However, a subsequent report of synthetic essentiality between <i>B. subtilis</i> MurJ and the flippase Amj suggested that they are necessary and sufficient. Here, we show that this effect is alleviated by excess synthesis of the enzyme responsible for Und-PP production. Thus, the inviability of a <i>murJ-amj</i> double mutant strain is not due to the essentiality of these enzymes for flipping Lipid II but is instead most likely a consequence of a reduction of free Und-PP levels. This result is consistent with a non-MOP-dependent pathway for Lipid II transport across the cytoplasmic membrane to enable cell wall peptidoglycan synthesis.IMPORTANCEThe assembly of peptidoglycan (PG), the typically essential polymer that provides structural integrity to bacterial cells, begins with the synthesis of the Lipid II monomer in the cytoplasm and along the cytoplasmic face of the inner membrane. Lipid II is then translocated across the membrane to the extracellular site of polymerization. The mechanistic basis for this process remains unclear, with genetic and/or biochemical evidence pointing to two different families of conserved membrane proteins. Here, we present genetic evidence that only one of these two families is essential in <i>Bacillus subtilis</i>.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0007825"},"PeriodicalIF":2.7,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial peptide plectasin recombinantly produced in <i>Escherichia coli</i> disintegrates cell walls of gram-positive bacteria, as proven by transmission electron and atomic force microscopy.","authors":"Matthias Müller, Sigrid Mayrhofer, Wisnu Arfian A Sudjarwo, Martin Gibisch, Christopher Tauer, Eva Berger, Cécile Brocard, José L Toca-Herrera, Gerald Striedner, Rainer Hahn, Monika Cserjan-Puschmann","doi":"10.1128/jb.00456-24","DOIUrl":"https://doi.org/10.1128/jb.00456-24","url":null,"abstract":"<p><p>Plectasin, an antimicrobial peptide, was initially isolated from the saprophytic fungus <i>Pseudoplectania nigrella</i>. This peptide, a member of the cysteine-stabilized α-helix and β-sheet family, has demonstrated potent antimicrobial activity against gram-positive pathogens, including strains resistant to conventional antibiotics. Our CASPON platform process enables the production of substantial quantities of plectasin, facilitating investigations on the activity and the mode of action of this recombinantly produced peptide. To this end, we developed an activity assay that reflects the growth inhibition of selected model bacteria, allowing for statistical analysis and evaluation of reproducibility. The mode of action was investigated using transmission electron microscopy and atomic force microscopy. The latter provided new insights into alterations in the cell surface of gram-positive bacteria treated with plectasin at the single-cell level. While the cell diameter remained unaltered, the roughness increased by up to twofold, and the cell stiffness decreased by approximately one-third in the four gram-positive bacterial strains tested. Statistical analysis of these morphological changes provides further insights into the effects and efficiency of antimicrobial peptides targeting pathogen cell walls.</p><p><strong>Importance: </strong>The rise of antibiotic-resistant bacteria is a major threat to global health. Antimicrobial peptides (AMPs) offer a promising way to combat this. With the CASPON technology, we produced the AMP plectasin comprising three disulfide bonds using <i>Escherichia coli</i>. The activity of purified plectasin with and without a CASPON fusion tag was determined for four gram-positive and four gram-negative bacteria. As anticipated, only gram-positive bacteria showed a growth inhibition response to un-tagged plectasin. Plectasin treatment on gram-positive bacteria was visualized via electron microscopy. Evaluation of atomic force microscopy indicated that plectasin treatment led to increased roughness but maintained thickness. Based on our study, we assume that the CASPON technology can be employed in the future for the production and characterization of medical-grade AMPs.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0045624"},"PeriodicalIF":2.7,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlled burn: interconnections between energy-spilling pathways and metabolic signaling in bacteria.","authors":"Nicolaus Jakowec, Steven E Finkel","doi":"10.1128/jb.00542-24","DOIUrl":"https://doi.org/10.1128/jb.00542-24","url":null,"abstract":"<p><p>Bacterial energy-spilling pathways-such as overflow metabolism and futile cycles-have been considered inefficient forms of metabolism that result from poor regulatory control or function as mechanisms to cope with excess energy. However, mounting evidence places these seemingly wasteful reactions at the fulcrum between metabolic signaling and stress adaptation in bacteria. Specifically, energy-spilling pathways may mediate the metabolic reprogramming observed when cells encounter growth-limiting constraints (i.e., nutrient limitation). Recent insights spotlight microbial metabolism as an intricate signaling network that coordinates physiological programming with energy and nutrient conditions. Such intracellular metabolic cross stalk is pivotal to survival in competitive, fluctuating environments that bacteria frequently encounter in nature. In light of this paradigm of metabolic signaling, energy-spilling pathways are increasingly recognized as regulatory strategies that enable metabolic rewiring in response to stress. Overflow metabolism or futile cycles may generate secondary metabolites with signaling properties, alter the flux of metabolic pathways and the rate of nutrient acquisition, or stimulate regulatory nodes to trigger specific metabolic programs in response to environmental challenges. Furthermore, the observation of such expensive pathways under laboratory conditions purported to be \"energy limiting\" may in fact suggest energy sufficiency, compelling us to rethink how we model energy limitation and starvation for bacteria.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0054224"},"PeriodicalIF":2.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143752781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}