International journal of food microbiology最新文献

{"title":"Cardamom and lemon balm nanoemulsion as a natural antimicrobial strategy against Listeria monocytogenes in Turkey meat","authors":"Mabrouk Sobhy ,&nbsp;Tamer Elsamahy ,&nbsp;Tariq Aziz ,&nbsp;Ashwag Shami ,&nbsp;Fahad Al-Asmari ,&nbsp;Fakhria A. Al-Joufi ,&nbsp;Esraa A. Abdelkarim ,&nbsp;Mahmoud Salah ,&nbsp;Haiying Cui ,&nbsp;Lin Lin","doi":"10.1016/j.ijfoodmicro.2025.111473","DOIUrl":"10.1016/j.ijfoodmicro.2025.111473","url":null,"abstract":"<div><div>The growing demand for safe and natural alternatives to synthetic food preservatives has driven interest in essential oil-based nanoformulations. This study aimed to develop and characterize a nanoemulsion containing cardamom and lemon balm essential oils (CEO-LBEO-NE), evaluate its antimicrobial efficacy against <em>Listeria monocytogenes</em>, elucidate its mechanism of action through assessment of membrane damage and intracellular leakage, and examine its application on turkey meat with attention to microbial safety, shelf life, and potential sensory impact. The CEO-LBEO-NE was synthesized using ultrasonication and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), revealing an average droplet size of 121.4 nm and a polydispersity index of 0.214. Antibacterial activity was assessed through agar-well diffusion, MIC/MBC determination, time-kill assays, and application on inoculated turkey meat. The CEO-LBEO-NE was compared with individual CEO, LBEO, and their conventional emulsion (CEO-LBEO-E) to assess relative antimicrobial performance. CEO-LBEO-NE demonstrated significantly higher antibacterial activity compared to CEO, LBEO, and their conventional emulsion (<em>p</em> &lt; 0.05), with MIC and MBC values of 6.25 mg/mL and 12.5 mg/mL, respectively. Mechanistic studies revealed a significant (<em>p</em> &lt; 0.0001) increase by 12.4-fold in nucleic acid leakage, a 7.4-fold increase in protein release (<em>p</em> &lt; 0.0001), and a significant (<em>p</em> = 0.0007) rise in extracellular potassium ion concentration from 1.42 ± 0.2 to 4.11 ± 0.46 ppm in the CEO-LBEO-NE group compared to the control, confirming pronounced bacterial membrane disruption, along with pronounced morphological disruption of L. <em>monocytogenes</em> cells. The surface coating of turkey meat using CEO-LBEO-NE significantly (<em>p</em> = 0.0136) reduced bacterial load and extended shelf life under refrigerated storage. Additionally, sensory analysis revealed insignificant variation in meat pH, color, the formation of methemoglobin and lipid oxidation compared to control (<em>p</em> &lt; 0.005) after treatment using CEO-LBEO-NE. These findings highlight the potential of CEO-LBEO-NE as a sustainable, natural antilisterial agent to improve food safety.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111473"},"PeriodicalIF":5.2,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the environmental response and assembly of rare and abundant taxa in zaopei employing daqu produced by different pressing patterns","authors":"Ping Huang ,&nbsp;Rongqing Zhou ,&nbsp;Zhiguo Huang ,&nbsp;Chongde Wu","doi":"10.1016/j.ijfoodmicro.2025.111471","DOIUrl":"10.1016/j.ijfoodmicro.2025.111471","url":null,"abstract":"<div><div><em>Baijiu</em> fermentation relies on complex microbial communities within <em>zaopei</em>, which are significantly shaped by the microbial starter <em>daqu</em>. This study investigated the rare and abundant taxa composition, and flavor characteristics of <em>zaopei</em> (fermented grains) employing <em>Nongxiangxing daqu</em> produced by different pressing patterns (mechanically pressed, artificially pressed) from microbial ecology perspective. Then, the origin, environmental response, assembly patterns and driving factors of rare and abundant taxa were revealed. The results indicated that both <em>Lactobacillus</em> and <em>Acetobacter</em> consistently dominated in rare bacteria and abundant bacteria of <em>zaopei</em>, the dominant abundant fungi were <em>Thermoascus</em> and <em>Issatchenkia</em>, while the dominant rare fungi were <em>Aspergillus</em> and <em>Pichia</em>. The microbial community of <em>zaopei</em> was significantly influenced by fungi originating from <em>daqu</em>, according to Fast expectation-maximization microbial source tracking (FEAST) analysis. Moreover, <em>daqu</em> significantly influenced the assembly process of abundant fungi taxa in <em>zaopei</em>, with the mechanically pressed <em>daqu</em> (MDQ) increased the proportion of heterogeneous selection. Moreover, water, starch and ethanol contents were important factors driving the rare bacteria assembly. Co-occurrence network analysis indicated that artificially pressed <em>daqu</em> (ADQ) enhanced microbial interactions in <em>zaopei</em>, which were closely related to rare bacteria. Meanwhile, Spearman's correlation between microorganisms and differential flavor compounds showed that fungal taxa (abundant <em>Clavispora</em>, rare <em>Pichia</em> and rare <em>Issatchenkia</em>) played a dominant role in flavor synthesis. These results contributed to a better understanding of the functional contributions of rare and abundant taxa in <em>baijiu</em> fermentation and provided theoretical support and technical guidance for regulating <em>baijiu</em> quality.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"445 ","pages":"Article 111471"},"PeriodicalIF":5.2,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacteriophage emulsion for prevention of Salmonella contamination in eggshells","authors":"Su Jin Jo ,&nbsp;Sang Guen Kim ,&nbsp;Sib Sankar Giri ,&nbsp;Sung Bin Lee ,&nbsp;Jae Hong Park ,&nbsp;Mae Hyun Hwang ,&nbsp;Da Sol Park ,&nbsp;Eun Jae Park ,&nbsp;Se Chang Park","doi":"10.1016/j.ijfoodmicro.2025.111470","DOIUrl":"10.1016/j.ijfoodmicro.2025.111470","url":null,"abstract":"<div><div><em>Salmonella</em> contamination of eggs poses a significant public health risk, contributing to foodborne illnesses worldwide and necessitating effective control measures to ensure food safety. Although chemical sanitization followed by refrigeration has been widely recommended to control bacterial contamination, it has limitations, including concerns over chemical residues, microbial resistance, and practical constraints in regions with limited cold-chain infrastructure. Bacteriophages are a promising alternative because of their specificity and ability to infect and lyse bacterial hosts. However, the application of phages to eggshells is hindered by rapid desiccation, which reduces their efficacy over time. In this study, we developed a bacteriophage-mineral oil emulsion to improve phage stability and enhance the antimicrobial efficacy on eggshell surfaces. A lytic <em>Salmonella</em> phage, pSe_SNUABM_01, was isolated, characterized, and incorporated into a mineral oil-based emulsion. The formulation was optimized by adjusting the oil-to-water ratio, mixing speed and emulsification duration. The 4:6 (<em>v</em>/v) oil-to-water ratio at 3000 rpm for 7 min demonstrated the highest stability after 21 days. On eggshell surfaces, the phage-emulsion coating significantly reduced <em>Salmonella</em> loads compared to untreated and conventionally coated eggs and maintained antibacterial activity over time. The emulsion also covered eggshell pores and cracks, thereby mitigating bacterial penetration. These findings suggest that phage emulsion coating could serve as a practical and effective strategy for reducing <em>Salmonella</em> contamination in eggshells, particularly in settings where refrigeration is not feasible. This approach combines physical protection with targeted antimicrobial activity, providing a viable alternative to conventional methods.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"445 ","pages":"Article 111470"},"PeriodicalIF":5.2,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a novel phage vB_YenP_WW2 for the inhibition against Yersinia enterocolitica biofilm and application in raw meat and milk","authors":"Zimeng Wang ,&nbsp;Ming Liu ,&nbsp;Tianxiang Xu ,&nbsp;Xiaoming Yuan ,&nbsp;Zekun Liu ,&nbsp;Hanfang Chen ,&nbsp;Jumei Zhang ,&nbsp;Yu Ding ,&nbsp;Qingping Wu ,&nbsp;Juan Wang","doi":"10.1016/j.ijfoodmicro.2025.111468","DOIUrl":"10.1016/j.ijfoodmicro.2025.111468","url":null,"abstract":"<div><div><em>Yersinia enterocolitica</em> is a significant zoonotic pathogen that causes severe gastrointestinal disease. In this study, vB_YenP_WW2 (WW2), a novel bacteriophage specific to <em>Y. enterocolitica</em>, was isolated and characterized. Stability analysis revealed that WW2 can retain its activity across a wide range of pH (4–12) and temperatures (4–60 °C). Host range analysis showed that WW2 exhibits broad lytic activity against various <em>Y. enterocolitica</em> strains, with a lysis rate of 27 %. Within 3 h, WW2 effectively reduced the bacterial load in raw meat and milk to undetectable levels. Additionally, WW2 significantly inhibited biofilm formation on polyethylene over 36 h and reduced biofilm formation by 70 % on stainless steel after 18 h of incubation. Compared to previously reported <em>Y. enterocolitica</em> phages, WW2 displayed a shorter latent period and stronger preventive effects against both <em>Y. enterocolitica</em> and its biofilms. These results suggested that WW2 holds promise as a novel antimicrobial agent against <em>Y. enterocolitica</em>.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111468"},"PeriodicalIF":5.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145250969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broad-host-range bacteriophages CBP1 and CBP2 with dual-species activity against Campylobacter jejuni and Campylobacter coli","authors":"Eunbyeol Ahn ,&nbsp;Jinshil Kim ,&nbsp;Joonbeom Kim ,&nbsp;Jeong In Hur ,&nbsp;Sangryeol Ryu ,&nbsp;Byeonghwa Jeon","doi":"10.1016/j.ijfoodmicro.2025.111469","DOIUrl":"10.1016/j.ijfoodmicro.2025.111469","url":null,"abstract":"<div><div><em>Campylobacter</em> spp., particularly <em>Campylobacter jejuni</em> and <em>Campylobacter coli</em>, are leading causes of foodborne illness worldwide, posing a significant public health challenge. Since the majority of <em>Campylobacter</em> infections are linked to contaminated poultry meat, the development of effective control strategies remains critical for food safety. Bacteriophage (phage) therapy has emerged as a promising biocontrol approach for enhancing food safety, yet its practical application has been limited by the narrow host specificity of most <em>Campylobacter</em> phages, which typically infect only specific strains or a single species. Here, we describe the isolation and characterization of two broad-host-range phages, CBP1 and CBP2, demonstrating remarkable dual-species infectivity against both <em>C. jejuni</em> and <em>C. coli</em>. These phages exhibited high infectivity across a phylogenetically diverse panel of <em>C. jejuni</em> and <em>C. coli</em> isolates from retail raw chicken, encompassing multiple clonal complexes. Notably, CBP1 and CBP2 effectively suppressed the growth of the predominant poultry-associated lineages, including CC-21 in <em>C. jejuni</em> and CC-828 in <em>C. coli</em>. Furthermore, the phages significantly reduced <em>Campylobacter</em> loads on artificially contaminated chicken meat, highlighting their practical potential as biocontrol agents in poultry production. Collectively, these findings demonstrate that CBP1 and CBP2 represent rare broad-host-range phages with dual-species activity, providing a versatile and effective intervention strategy for reducing <em>Campylobacter</em> contamination in poultry production systems.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111469"},"PeriodicalIF":5.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoemulsion enhances antimicrobial efficacy of Spanish marjoram essential oil against Listeria monocytogenes and E. coli O157:H7 on spinach leaves","authors":"Karolina Kraśniewska ,&nbsp;Małgorzata Gniewosz ,&nbsp;Achyut Adhikari","doi":"10.1016/j.ijfoodmicro.2025.111466","DOIUrl":"10.1016/j.ijfoodmicro.2025.111466","url":null,"abstract":"<div><div>Minimally processed vegetables due to the lack of thermal processing during manufacturing are at increasing risk of microbiological contamination. Effective disinfection strategies are therefore critical to ensure the safety of these products.</div><div>This study investigated the potential of Spanish marjoram essential oil (SMEO) nanoemulsion as a sustainable alternative to commercially used chlorine-based products for disinfecting minimally processed leafy greens. In the first stage of this study three SMEO nanoemulsion formulations were prepared using different concentrations of Tween 80 surfactant (0.5 % to 5 %) via ultrasonic homogenization. The nanoemulsions were characterized for particle size, polydispersity index, zeta potential, storage stability and antibacterial activity. Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were determined against <em>Listeria monocytogenes</em> and <em>Escherichia coli</em> O157:H7. Increasing Tween 80 concentration significantly improved nanoemulsion properties, reducing droplet size, enhancing homogeneity, and storage stability. The MIC and MBC values ranged from 0.78 to 1.56 mg/mL for all the formulations. Afterwords, selected SMEO nanoemulsion at 1xMICs and 2xMICs concentrations were compared to 0.02 % sodium hypochlorite (NaOCl) against <em>L. monocytogenes</em> and <em>E. coli</em> O157:H7 on spinach leaves. Both SMEO nanoemulsions exhibited significant antimicrobial activity, effectively reducing pathogen populations on produce surfaces with similar or better effectiveness compared to NaOCl. Furthermore, the application of the nanoemulsion did not adversely affect the color or visual quality of spinach leaves. This study supports the use of SMEO nanoemulsion as an effective and eco-friendly alternative to traditional chemical sanitizers for maintaining the safety and quality of fresh produce.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111466"},"PeriodicalIF":5.2,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frontier research on the risk of spoilage microorganisms in refrigerated marine fish: From regional to global perspectives","authors":"Gan Wu ,&nbsp;Zhaoyang Ding ,&nbsp;Jinfeng Wang ,&nbsp;Jing Xie","doi":"10.1016/j.ijfoodmicro.2025.111465","DOIUrl":"10.1016/j.ijfoodmicro.2025.111465","url":null,"abstract":"<div><div>Microbial spoilage is creating safety risks and significant wastage of refrigerated marine fish. Spoilage microorganisms possess distinct physiological adaptations that enable them to contribute to the spoilage of refrigerated marine fish, thereby complicating the accuracy of microbial risk predictions and the efficacy of control strategies. This review integrates research findings from diverse geographical regions to elucidate mechanisms of microbial spoilage and underscores the ongoing challenges in cross-regional collaborative studies. Omics serve as guiding tools for elucidating the molecular mechanisms by which metabolite mediate spoilage microorganisms-induced deterioration of flavor, texture, and safety. Quantitative Microbial Risk Assessment (QMRA) provides a critical framework for risk prediction, with its future development being intrinsically linked to the integration of omics data, rapid fluorescence sensing, and artificial intelligence (AI) for enhanced prediction and modeling. In conclusion, this review underscores the critical role of spoilage microorganisms in the deterioration of refrigerated marine fish, highlights the complex interplay between microbial ecology, cold adaptation, and spoilage potential, and emphasizes the necessity for collaborative global efforts. Advancing research on native microbial communities, molecular spoilage mechanisms, and AI-powered QMRA frameworks is paramount for reducing food waste, enhancing food safety risk assessment, and the sustainable development of preservation technology.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111465"},"PeriodicalIF":5.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “A large sampling study on the occurrence and characteristics of Pseudomonas aeruginosa and heterotrophic bacteria in mineral water over seasons and in different containers” [Int. J. Food Microbiol. 443 (2025) 111427 (2 December)]","authors":"Beatriz S. Silva ,&nbsp;Marianna M. Furtado ,&nbsp;Luísa Freire ,&nbsp;Sarah Lee ,&nbsp;Genesy P. Jorge ,&nbsp;Giovanna Daldosso ,&nbsp;Christian E. Silva ,&nbsp;Lúcio Vieira-Junior ,&nbsp;Wilson J.F. Lemos Junior ,&nbsp;Carlos Augusto F. Oliveira ,&nbsp;Marcelo Brocchi ,&nbsp;Anderson S. Sant'Ana","doi":"10.1016/j.ijfoodmicro.2025.111448","DOIUrl":"10.1016/j.ijfoodmicro.2025.111448","url":null,"abstract":"","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111448"},"PeriodicalIF":5.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145130712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effectiveness of slurry ice for reducing Campylobacter on free-range poultry carcasses","authors":"Cristina Calvo-Fernandez ,&nbsp;Brian Lassen ,&nbsp;Annette Nygaard Jensen ,&nbsp;Nao Takeuchi-Storm","doi":"10.1016/j.ijfoodmicro.2025.111464","DOIUrl":"10.1016/j.ijfoodmicro.2025.111464","url":null,"abstract":"<div><div><em>Campylobacter</em>, a leading cause of foodborne illnesses in the EU, presents significant challenges in free-range broilers due to their limited biosecurity and increased environmental exposure. IceGun® is a device designed to spray slurry ice on poultry carcasses to enhance chilling, and its effectiveness in reducing <em>Campylobacter</em> was evaluated in a Danish slaughterhouse specialising in free-range broilers. In each of four trials, forty carcasses from a <em>Campylobacter</em>-positive flock were randomly selected, and half were subjected to air chilling and <em>slurry ice</em> treatment, while the other half received only air chilling. Neck and leg skin samples were collected after chilling and analysed for <em>Campylobacter</em>. Selected <em>Campylobacter</em> isolates (<em>n</em> = 90) were whole-genome sequenced to assess genetic diversity. Additionally, the carcasses were packaged in modified atmosphere packaging (MAP), refrigerated over the shelf life period, and analysed for microbiological, chemical, and sensory parameters. Of the four flocks tested, slurry ice application significantly reduced <em>Campylobacter</em> concentrations on neck skin by 0.44 log₁₀ CFU/g, while effects on leg skin were less pronounced. <em>Slurry ice</em> treatment accelerated chilling without affecting product quality during the shelf life period under MAP and refrigeration. Genomic analyses revealed substantial genetic diversity among the isolates, with nine predominant sequence types (STs), including ST-52, associated with human infections. Some STs were present beyond the defined shelf life, suggesting resilience under refrigeration and MAP. Antibiotic resistance profiling showed a low prevalence of resistance genes among the isolates. The study highlights the dual benefits of slurry ice technology in improving food safety without compromising product quality in free-range broiler processing.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111464"},"PeriodicalIF":5.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of riboflavin and nicotinamide in vitamin B12 production by Propionibacterium freudenreichii","authors":"Bhawani Chamlagain ,&nbsp;Iida Loivamaa ,&nbsp;Ruoxi Zhang ,&nbsp;Emmi Hovilehto ,&nbsp;Paulina Deptula ,&nbsp;Minnamari Edelmann ,&nbsp;Susanna Kariluoto ,&nbsp;Vieno Piironen ,&nbsp;Pekka Varmanen","doi":"10.1016/j.ijfoodmicro.2025.111463","DOIUrl":"10.1016/j.ijfoodmicro.2025.111463","url":null,"abstract":"<div><div>Riboflavin (RF) serves as a precursor for the biosynthesis of 5,6-dimethylbenzimidazole (DMBI), the lower ligand of vitamin B12, in <em>Propionibacterium freudenreichii</em>. Nicotinamide (NAM) has been reported to enhance this biosynthetic pathway. In this study, we investigated the effect of RF and NAM supplementation on vitamin B12 production by <em>P. freudenreichii</em> DSM 20271 in barley malt extract-based model medium. A medium containing 10 % (<em>w</em>/<em>v</em>) concentrated malt extract supplemented with lactate and tryptone supported superior growth and B12 production. RF (1, 3 and 40 μM with 27 mM NAM), and NAM (0.1, 0.6 and 27 mM with 3 μM RF) were evaluated for their impact, with 100 μM DMBI used as a reference. RF concentrations ≥3 μM significantly enhanced B12 production, while NAM was effective only at 27 mM. Growth and metabolite profiles were largely unaffected, suggesting that increased B12 synthesis resulted from improved precursor availability rather than enhanced biomass. Transcriptomic analysis revealed significant downregulation of RF biosynthesis genes, consistent with feedback inhibition from exogenous RF, while B12 biosynthesis genes remained transcriptionally stable, indicating that the observed increase in B12 production is primarily regulated at the metabolic rather transcriptional level. These findings demonstrate that B12 production in <em>P. freudenreichii</em> can be enhanced using RF and NAM precursors, but practical applications must balance efficacy with NAM safety limits for use in B12-enriched fermented foods.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"444 ","pages":"Article 111463"},"PeriodicalIF":5.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}