Dairy starter cultures are often optimized for rapid acidification, but the relationship between growth rate and secondary metabolite (e.g. flavour) formation is unclear. We here investigated this relationship by modulating the growth rate of L. cremoris NCDO712 using partial translation inhibition (allowing growth at slower rates) or by varying temperatures in defined media and milk. Subsequently the proteome was conserved by full translational inhibition and cells were incubated in defined medium or in a cheese model system for up to 14 days to assess volatile compound formation. Proteome analysis of the cells revealed three protein clusters: ribosome-related (A), metabolism-related (B), and core (constant). Partial translation inhibition of the pre-cultures in defined media increased ribosome-related proteins and decreased amino acid metabolism proteins, including those involved in 3-methylbutanal formation. However, temperature-driven growth rate changes and partial translation inhibition in milk showed minimal changes in ribosome-related and metabolic protein fractions. Crucially, slower pre-culture growth significantly reduced key flavour compound production (up to 30-fold). These findings demonstrate that rapid growth does not necessarily sacrifice metabolic protein levels in L. cremoris NCDO712, and that pre-culture growth rates can influence secondary metabolite production, independent of enzyme levels.
{"title":"Growth rate influences flavour formation in Lactococcus cremoris independently of metabolic protein levels","authors":"Avis Dwi Wahyu Nugroho , Berdien van Olst , Douwe Molenaar , Siming Li , Adriano Guiso , Sjef Boeren , Michiel Kleerebezem , Herwig Bachmann","doi":"10.1016/j.ijfoodmicro.2026.111662","DOIUrl":"10.1016/j.ijfoodmicro.2026.111662","url":null,"abstract":"<div><div>Dairy starter cultures are often optimized for rapid acidification, but the relationship between growth rate and secondary metabolite (e.g. flavour) formation is unclear. We here investigated this relationship by modulating the growth rate of <em>L. cremoris</em> NCDO712 using partial translation inhibition (allowing growth at slower rates) or by varying temperatures in defined media and milk. Subsequently the proteome was conserved by full translational inhibition and cells were incubated in defined medium or in a cheese model system for up to 14 days to assess volatile compound formation. Proteome analysis of the cells revealed three protein clusters: ribosome-related (A), metabolism-related (B), and core (constant). Partial translation inhibition of the pre-cultures in defined media increased ribosome-related proteins and decreased amino acid metabolism proteins, including those involved in 3-methylbutanal formation. However, temperature-driven growth rate changes and partial translation inhibition in milk showed minimal changes in ribosome-related and metabolic protein fractions. Crucially, slower pre-culture growth significantly reduced key flavour compound production (up to 30-fold). These findings demonstrate that rapid growth does not necessarily sacrifice metabolic protein levels in <em>L. cremoris</em> NCDO712, and that pre-culture growth rates can influence secondary metabolite production, independent of enzyme levels.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"451 ","pages":"Article 111662"},"PeriodicalIF":5.2,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098681","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}
Pub Date : 2026-01-27DOI: 10.1016/j.ijfoodmicro.2026.111663
Lou Xinhao , Zhang Jinyi , Jin Xuewu , Cai Qilong , Liu Runqi , Gang Wang , O. Olaniran Ademola , Xu Jianhong , Dong Fei
To confirm the most susceptible stage of Fusarium infection and evaluate the pathogenicity of different chemotypes of Fusarium isolates are essential for managing Fusarium head blight (FHB). Extensive research has been conducted on wheat and barley, while there has been limited studies in rice. A 2-year greenhouse experiment was conducted to reveal the effects of infection timing and chemotype of Fusarium asiaticum on FHB severity and mycotoxin accumulation in four rice varieties. The results showed that all the rice varieties could be infected at 0, 3, 6, 9, and 12 days after anthesis (daa) by R3 (the 3-acetyldeoxynivalenol chemotype) and R5 (the nivalenol chemotype). The area under the disease progress curve (AUDPC), total trichothecenes, and fungal biomass caused by R3 were obviously lower than that caused by R5 across all varieties. Moreover, susceptible varieties exhibited higher values for these parameters than resistant varieties following inoculation with R3 or R5. Notably, the most seriously symptoms, highest total trichothecenes accumulation, and greatest fungal biomass were observed when inoculation at 3 daa, which was significantly higher than that at other inoculation timing (P < 0.05), and tended to be 3 daa > 6 daa > 0 daa > 9 daa > 12 daa. In addition, a significantly positive correlation (P < 0.01) was observed between AUDPC and total trichothecenes, AUDPC and fungal biomass, and total trichothecenes and fungal biomass, respectively.
确定镰刀菌感染的最敏感阶段和评价不同化学型镰刀菌分离物的致病性是防治镰刀菌头疫病的必要条件。对小麦和大麦进行了广泛的研究，而对水稻的研究却很有限。通过2年温室试验，研究了亚洲镰刀菌侵染时间和化学型对4个水稻品种赤霉病严重程度和霉菌毒素积累的影响。结果表明，所有水稻品种均可在开花后0、3、6、9和12 d分别被3-乙酰脱氧雪腐镰刀菌醇R3和雪腐镰刀菌醇R5感染。在所有品种中，由R3引起的疾病进展曲线下面积（AUDPC）、总菌数和真菌生物量均明显低于由R5引起的。此外，接种R3或R5后，易感品种的这些参数值均高于抗性品种。值得注意的是，接种3 d时症状最严重，毛孢子总积累量最高，真菌生物量最大，显著高于其他接种时间（P < 0.05），并趋向于接种3 d >； 6 d > 0 d > 9 d > 12 d。此外，AUDPC与总菌群生物量、与真菌生物量、总菌群生物量呈极显著正相关（P < 0.01）。
{"title":"Effect of infection timing and chemotype of Fusarium asiaticum on fusarium head blight and mycotoxin accumulation in rice","authors":"Lou Xinhao , Zhang Jinyi , Jin Xuewu , Cai Qilong , Liu Runqi , Gang Wang , O. Olaniran Ademola , Xu Jianhong , Dong Fei","doi":"10.1016/j.ijfoodmicro.2026.111663","DOIUrl":"10.1016/j.ijfoodmicro.2026.111663","url":null,"abstract":"<div><div>To confirm the most susceptible stage of <em>Fusarium</em> infection and evaluate the pathogenicity of different chemotypes of <em>Fusarium</em> isolates are essential for managing Fusarium head blight (FHB). Extensive research has been conducted on wheat and barley, while there has been limited studies in rice. A 2-year greenhouse experiment was conducted to reveal the effects of infection timing and chemotype of <em>Fusarium asiaticum</em> on FHB severity and mycotoxin accumulation in four rice varieties. The results showed that all the rice varieties could be infected at 0, 3, 6, 9, and 12 days after anthesis (daa) by R3 (the 3-acetyldeoxynivalenol chemotype) and R5 (the nivalenol chemotype). The area under the disease progress curve (AUDPC), total trichothecenes, and fungal biomass caused by R3 were obviously lower than that caused by R5 across all varieties. Moreover, susceptible varieties exhibited higher values for these parameters than resistant varieties following inoculation with R3 or R5. Notably, the most seriously symptoms, highest total trichothecenes accumulation, and greatest fungal biomass were observed when inoculation at 3 daa, which was significantly higher than that at other inoculation timing (<em>P</em> < 0.05), and tended to be 3 daa > 6 daa > 0 daa > 9 daa > 12 daa. In addition, a significantly positive correlation (<em>P</em> < 0.01) was observed between AUDPC and total trichothecenes, AUDPC and fungal biomass, and total trichothecenes and fungal biomass, respectively.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111663"},"PeriodicalIF":5.2,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074452","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}
Pub Date : 2026-01-25DOI: 10.1016/j.ijfoodmicro.2026.111658
Luana Virgínia Souza , Andressa Falqueto , Valéria Quintana Cavicchioli , Almir Custodio Batista Junior , João Victor Ataíde Oliveira , Andréa Rodrigues Chaves , Cíntia Minafra , Cinzia Caggia , Cinzia Lucia Randazzo , Antonio Fernandes de Carvalho , Luís Augusto Nero
The dairy industry has increasingly seeking natural strategies to enhance food safety and quality. Fungal contamination remains a major challenge due to spoilage, economic losses, and mycotoxin production, making bioprotective microbial cultures a promising alternative. This study aimed to investigate the antifungal potential of five Lactiplantibacillus plantarum strains (M3.1, M3.3, M3.6, R3.2, and R3.6) against Aspergillus niger and Penicillium chrysogenum. All strains significantly inhibited fungal growth, as demonstrated by in vitro assays and reductions in fungal biomass. Scanning electron microscopy (SEM) revealed severe morphological damage to fungal spores, including surface disruption, deformation, and shrinkage. Metabolomic analyses identified the production of organic acids, including lactic, acetic, succinic, malic, propionic, butyric, and formic acids, using high-performance liquid chromatography (HPLC), as well as 35 additional metabolites, mainly amino acids, fatty acids, cyclic dipeptides, phenolic compounds, and esters, using high-performance liquid chromatography–mass spectrometry (HPLC-MS), revealing a synergistic and multifactorial antifungal mechanism. In a cheese model system, all strains completely inhibited P. chrysogenum, while strains M3.3, M3.6, and R3.2 fully inhibited A. niger. These findings demonstrate the strong antifungal activity of L. plantarum strains and support their application as bioprotective cultures in dairy products.
{"title":"Metabolomic profiling of antifungal Lactiplantibacillus plantarum strains and their inhibition of Aspergillus niger and Penicillium chrysogenum in a cheese matrix","authors":"Luana Virgínia Souza , Andressa Falqueto , Valéria Quintana Cavicchioli , Almir Custodio Batista Junior , João Victor Ataíde Oliveira , Andréa Rodrigues Chaves , Cíntia Minafra , Cinzia Caggia , Cinzia Lucia Randazzo , Antonio Fernandes de Carvalho , Luís Augusto Nero","doi":"10.1016/j.ijfoodmicro.2026.111658","DOIUrl":"10.1016/j.ijfoodmicro.2026.111658","url":null,"abstract":"<div><div>The dairy industry has increasingly seeking natural strategies to enhance food safety and quality. Fungal contamination remains a major challenge due to spoilage, economic losses, and mycotoxin production, making bioprotective microbial cultures a promising alternative. This study aimed to investigate the antifungal potential of five <em>Lactiplantibacillus plantarum</em> strains (M3.1, M3.3, M3.6, R3.2, and R3.6) against <em>Aspergillus niger</em> and <em>Penicillium chrysogenum</em>. All strains significantly inhibited fungal growth, as demonstrated by in vitro assays and reductions in fungal biomass. Scanning electron microscopy (SEM) revealed severe morphological damage to fungal spores, including surface disruption, deformation, and shrinkage. Metabolomic analyses identified the production of organic acids, including lactic, acetic, succinic, malic, propionic, butyric, and formic acids, using high-performance liquid chromatography (HPLC), as well as 35 additional metabolites, mainly amino acids, fatty acids, cyclic dipeptides, phenolic compounds, and esters, using high-performance liquid chromatography–mass spectrometry (HPLC-MS), revealing a synergistic and multifactorial antifungal mechanism. In a cheese model system, all strains completely inhibited <em>P. chrysogenum</em>, while strains M3.3, M3.6, and R3.2 fully inhibited <em>A. niger</em>. These findings demonstrate the strong antifungal activity of <em>L. plantarum</em> strains and support their application as bioprotective cultures in dairy products.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111658"},"PeriodicalIF":5.2,"publicationDate":"2026-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074358","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}
Pub Date : 2026-01-23DOI: 10.1016/j.ijfoodmicro.2026.111659
Sávio Sandes , Naiara Figueiredo , Sumaia Pires , Debora Assis , Silvia Pedroso , Maria José Paiva , Elisabeth Neumann , Veronica O. Alvarenga , Carmen J. Contreras-Castillo , Anderson S. Sant'Ana
Beef is a highly perishable product due to its high moisture content, neutral pH, and rich nutrient profile, which favor microbial growth and spoilage. While vacuum packaging extends shelf life by limiting aerobic bacteria, it may promote the proliferation of anaerobic and facultative anaerobic spoilage organisms, leading to blown pack spoilage. This study investigated the effects of lactic acid spraying on split carcasses categorized by two pH levels (high or ideal) on microbial succession and volatile organic compound (VOC) production in vacuum-packaged sirloins, stored at 0 °C, 4 °C, and 7 °C for up to 120 days. Using culture-based methods, 16S rRNA gene sequencing, and VOC profiling, it has been found that lactic acid treatment significantly reduced initial bacterial loads, especially in high-pH split carcasses (P < 0,05), and modulated microbial communities over time. Treated samples exhibited a lower incidence of blown pack spoilage (BPS) under specific storage time–temperature conditions. Nevertheless, bacterial changes under specific time–temperature storage conditions were characterized by a microbiota dominated by Lactococcus, Lactobacillus, Leuconostoc, Enterococcus, Carnobacterium, Hafnia–Obesumbacterium, and Serratia, regardless type of treatment. Overall microbial diversity was not significantly affected; however, the composition of dominant bacterial genera and VOC profiles differed between treated and non-treated groups, suggesting that specific bacterial taxa and compounds may serve as indicators of spoilage progression in vacuum-packed meat under defined storage conditions.
{"title":"Lactic acid spraying on split carcasses reshapes microbial succession and reduces the occurrence of blown pack spoilage in vacuum-packaged beef stored at different temperatures over extended shelf life","authors":"Sávio Sandes , Naiara Figueiredo , Sumaia Pires , Debora Assis , Silvia Pedroso , Maria José Paiva , Elisabeth Neumann , Veronica O. Alvarenga , Carmen J. Contreras-Castillo , Anderson S. Sant'Ana","doi":"10.1016/j.ijfoodmicro.2026.111659","DOIUrl":"10.1016/j.ijfoodmicro.2026.111659","url":null,"abstract":"<div><div>Beef is a highly perishable product due to its high moisture content, neutral pH, and rich nutrient profile, which favor microbial growth and spoilage. While vacuum packaging extends shelf life by limiting aerobic bacteria, it may promote the proliferation of anaerobic and facultative anaerobic spoilage organisms, leading to blown pack spoilage. This study investigated the effects of lactic acid spraying on split carcasses categorized by two pH levels (high or ideal) on microbial succession and volatile organic compound (VOC) production in vacuum-packaged sirloins, stored at 0 °C, 4 °C, and 7 °C for up to 120 days. Using culture-based methods, 16S rRNA gene sequencing, and VOC profiling, it has been found that lactic acid treatment significantly reduced initial bacterial loads, especially in high-pH split carcasses (<em>P</em> < 0,05), and modulated microbial communities over time. Treated samples exhibited a lower incidence of blown pack spoilage (BPS) under specific storage time–temperature conditions. Nevertheless, bacterial changes under specific time–temperature storage conditions were characterized by a microbiota dominated by <em>Lactococcus</em>, <em>Lactobacillus</em>, <em>Leuconostoc</em>, <em>Enterococcus</em>, <em>Carnobacterium</em>, <em>Hafnia–Obesumbacterium</em>, and <em>Serratia</em>, regardless type of treatment. Overall microbial diversity was not significantly affected; however, the composition of dominant bacterial genera and VOC profiles differed between treated and non-treated groups, suggesting that specific bacterial taxa and compounds may serve as indicators of spoilage progression in vacuum-packed meat under defined storage conditions.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111659"},"PeriodicalIF":5.2,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146062908","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}
Pub Date : 2026-01-23DOI: 10.1016/j.ijfoodmicro.2026.111660
Boqin Zhang , Mengbo Wang , Jia Zheng , Chenxi Yu , Chunhui Wei , Junyu Ren , Shouying Sun , Guoming Wang , Jinhua Wang , Yanping Lu , Liangcai Lin , Cuiying Zhang
Pichia kudriavzevii is a dominant yeast species in Chinese baijiu fermentation, yet its intraspecific diversity remains underexplored. This study used metabolomics and metagenomics analysis to investigate the impact of four distinct P. kudriavzevii strains (PK12, PK25, PK97, and PK360) on the metabolite profiles and microbial community structure in a controlled baijiu solid-state fermentation. Metabolomics analysis identified 49 key volatile compounds and 2792 non-volatile metabolites. Strain PK97 exhibited exceptional capacity for butanoic acid metabolism, inducing a 55.27-fold increase in butanoic acid and a 30.54-fold enhancement in ethyl butanoate production. Strain PK25 specialized in acetoin biosynthesis, while PK360 maximized 2-phenylethanol production. Metagenomic analysis uncovered that strains PK12, PK25, and PK360 promoted Lactobacillus acetotolerans population, increasing its relative abundance to 67.39%, 58.57%, and 71.79%, respectively. In contrast, strain PK97 orchestrated a dramatic ecological shift, elevating Enterobacter mori abundance from 0.56% to 17.60%, transforming the community from Lactobacillus-dominated to Enterobacteriaceae-enriched. Integration of metabolomic and metagenomic data revealed that strain PK97's promotion of Enterobacter mori correlated with significant upregulation of key enzymes including α-amylase (EC 3.2.1.1), enoyl-CoA hydratase (EC 4.2.1.17), and succinyl-CoA synthetase (EC 6.2.1.5), creating a metabolic environment favoring enhanced starch hydrolysis, altered TCA cycle flux, and butanoic acid accumulation. Strain PK25 specifically upregulated acetyl-CoA hydrolase (EC 3.1.2.1), facilitating acetic acid and acetoin formation. Strain PK360 enhanced glucose pyrophosphorylase (EC 2.7.7.9) and asparagine synthetase (EC 6.3.1.1) activities, accelerating galactose metabolism and amino acid transformations. These findings illustrate the impact of P. kudriavzevii intraspecific diversity on reshaping microbial ecology and flavor chemistry in Chinese baijiu, offering novel insights for targeted fermentation control and quality enhancement strategies in baijiu production.
{"title":"Strain-specific impacts of Pichia kudriavzevii on metabolite profiles and microbial community dynamics in Chinese Baijiu fermentation: Integrated metabolomics and metagenomics analysis","authors":"Boqin Zhang , Mengbo Wang , Jia Zheng , Chenxi Yu , Chunhui Wei , Junyu Ren , Shouying Sun , Guoming Wang , Jinhua Wang , Yanping Lu , Liangcai Lin , Cuiying Zhang","doi":"10.1016/j.ijfoodmicro.2026.111660","DOIUrl":"10.1016/j.ijfoodmicro.2026.111660","url":null,"abstract":"<div><div><em>Pichia kudriavzevii</em> is a dominant yeast species in Chinese baijiu fermentation, yet its intraspecific diversity remains underexplored. This study used metabolomics and metagenomics analysis to investigate the impact of four distinct <em>P. kudriavzevii</em> strains (PK12, PK25, PK97, and PK360) on the metabolite profiles and microbial community structure in a controlled baijiu solid-state fermentation. Metabolomics analysis identified 49 key volatile compounds and 2792 non-volatile metabolites. Strain PK97 exhibited exceptional capacity for butanoic acid metabolism, inducing a 55.27-fold increase in butanoic acid and a 30.54-fold enhancement in ethyl butanoate production. Strain PK25 specialized in acetoin biosynthesis, while PK360 maximized 2-phenylethanol production. Metagenomic analysis uncovered that strains PK12, PK25, and PK360 promoted <em>Lactobacillus acetotolerans</em> population, increasing its relative abundance to 67.39%, 58.57%, and 71.79%, respectively. In contrast, strain PK97 orchestrated a dramatic ecological shift, elevating <em>Enterobacter mori</em> abundance from 0.56% to 17.60%, transforming the community from <em>Lactobacillus</em>-dominated to <em>Enterobacteriaceae</em>-enriched. Integration of metabolomic and metagenomic data revealed that strain PK97's promotion of <em>Enterobacter mori</em> correlated with significant upregulation of key enzymes including α-amylase (EC 3.2.1.1), enoyl-CoA hydratase (EC 4.2.1.17), and succinyl-CoA synthetase (EC 6.2.1.5), creating a metabolic environment favoring enhanced starch hydrolysis, altered TCA cycle flux, and butanoic acid accumulation. Strain PK25 specifically upregulated acetyl-CoA hydrolase (EC 3.1.2.1), facilitating acetic acid and acetoin formation. Strain PK360 enhanced glucose pyrophosphorylase (EC 2.7.7.9) and asparagine synthetase (EC 6.3.1.1) activities, accelerating galactose metabolism and amino acid transformations. These findings illustrate the impact of <em>P. kudriavzevii</em> intraspecific diversity on reshaping microbial ecology and flavor chemistry in Chinese baijiu, offering novel insights for targeted fermentation control and quality enhancement strategies in baijiu production.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111660"},"PeriodicalIF":5.2,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146062927","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}
Pub Date : 2026-01-23DOI: 10.1016/j.ijfoodmicro.2026.111661
Hao Zhou , Lijun Yan , Boyang Xu , Ling Zhang , Ruijuan Wang , Qin Chen , Xingjiang Li
Pit mud serves as a habitat for functional bacteria involved in Baijiu fermentation. While pH is recognized as a key driver of bacterial succession in pit mud, the underlying pattern remains insufficiently characterized. This study systematically investigated the relationship between pH and bacterial communities in pit mud by integrating dataset analysis with pH gradient experiments. The results revealed strong correlations between pH and the key bacterial families, which occurred not only across the time dimension but also in relation to spatial heterogeneity or artificial disturbance. Along the pH gradient, heterogeneous selection may govern bacterial succession. As pH increased, the appearance of Oscillospiraceae signaled the onset of bacterial succession, while the near disappearance of Lactobacillaceae indicated enhanced stability. Six representative genera were further studied, revealing distinct genomic features that changed consistently with pH. During bacterial succession, the abundance of Lactobacillus declined, which predominantly carries genes associated with lactate and acetate metabolism. In contrast, the abundance of Caproicibacterium, which possesses a complete gene cluster for reverse β-oxidation, increased. The pH gradient experiments confirmed that pH influences bacterial assembly mainly through heterogeneous selection, which appeared to be facilitated both by the lactate-utilizing ability of Caproicibacterium and the pH-mediated suppression of Lactobacillus. These findings advance the theoretical understanding of pit mud aging and contribute to the optimization of Baijiu fermentation.
{"title":"Heterogeneous selection driven by pH determines the successional pattern of bacterial communities in pit mud used for Baijiu fermentation","authors":"Hao Zhou , Lijun Yan , Boyang Xu , Ling Zhang , Ruijuan Wang , Qin Chen , Xingjiang Li","doi":"10.1016/j.ijfoodmicro.2026.111661","DOIUrl":"10.1016/j.ijfoodmicro.2026.111661","url":null,"abstract":"<div><div>Pit mud serves as a habitat for functional bacteria involved in Baijiu fermentation. While pH is recognized as a key driver of bacterial succession in pit mud, the underlying pattern remains insufficiently characterized. This study systematically investigated the relationship between pH and bacterial communities in pit mud by integrating dataset analysis with pH gradient experiments. The results revealed strong correlations between pH and the key bacterial families, which occurred not only across the time dimension but also in relation to spatial heterogeneity or artificial disturbance. Along the pH gradient, heterogeneous selection may govern bacterial succession. As pH increased, the appearance of <em>Oscillospiraceae</em> signaled the onset of bacterial succession, while the near disappearance of <em>Lactobacillaceae</em> indicated enhanced stability. Six representative genera were further studied, revealing distinct genomic features that changed consistently with pH. During bacterial succession, the abundance of <em>Lactobacillus</em> declined, which predominantly carries genes associated with lactate and acetate metabolism. In contrast, the abundance of <em>Caproicibacterium</em>, which possesses a complete gene cluster for reverse β-oxidation, increased. The pH gradient experiments confirmed that pH influences bacterial assembly mainly through heterogeneous selection, which appeared to be facilitated both by the lactate-utilizing ability of <em>Caproicibacterium</em> and the pH-mediated suppression of <em>Lactobacillus</em>. These findings advance the theoretical understanding of pit mud aging and contribute to the optimization of Baijiu fermentation.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111661"},"PeriodicalIF":5.2,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146062840","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}
Pub Date : 2026-01-23DOI: 10.1016/j.ijfoodmicro.2026.111657
Wenqi Yang , Xiangrong Wang , Shuilin Liu , Le An , Anqi Ren , Xinran Lv , Jianrong Li , Xuepeng Li , Meihui Li
Food spoilage typically arises from bacterial consortia rather than individual species. Pseudomonas fluorescens and Hafnia alvei employ quorum sensing (QS)-mediated biofilm formation to accelerate spoilage in salmon. This study constructed a dual-species biofilm model of P. fluorescens and H. alvei to simulate the actual spoilage environment in salmon, and investigated the anti-biofilm potential of penicillin V acylase (LpPVA) from Lactiplantibacillus plantarum YP4–1-2 against mono- and dual-species systems. The results showed that a more compact dual-species biofilm with elevated levels of AHLs, higher metabolic activity, and greater extracellular polymeric substances (EPS) was observed when P. fluorescens and H. alvei were co-cultured at a ratio of 1:1. In salmon juice, the inhibitory effect of LpPVA against P. fluorescens, H. alvei, and dual-species biofilm were significantly higher than that in the LB medium, reaching 66.93%, 70.71%, and 63.66% respectively. LpPVA also significantly reduced AHL levels and suppressed both metabolic activity and EPS production in P. fluorescens, H. alvei, and dual-species biofilms, with inhibitory rates on AHLs of 97.23%, 95.18% and 98.30%, respectively; on metabolic activity of 50.16%, 47.08% and 51.16%, respectively; and on extracellular polysaccharides and proteins of 75.78% and 40.10%, 78.63% and 46.01%, 67.42% and 50.68%, respectively. Additionally, LpPVA down-regulated QS-related genes and biofilm-related genes to inhibit biofilm formation. The study demonstrates that the interactions between P. fluorescens and H. alvei in a dual-species promoted the formation of complex biofilm structures by increasing AHLs, and their sensitivity to LpPVA provides a novel strategy for controlling multi-species contamination in aquatic products.
{"title":"Dual-species biofilm formation of Pseudomonas fluorescens and Hafnia alvei and their susceptibility to penicillin V acylase from Lactiplantibacillus plantarum YP4-1-2","authors":"Wenqi Yang , Xiangrong Wang , Shuilin Liu , Le An , Anqi Ren , Xinran Lv , Jianrong Li , Xuepeng Li , Meihui Li","doi":"10.1016/j.ijfoodmicro.2026.111657","DOIUrl":"10.1016/j.ijfoodmicro.2026.111657","url":null,"abstract":"<div><div>Food spoilage typically arises from bacterial consortia rather than individual species. <em>Pseudomonas fluorescens</em> and <em>Hafnia alvei</em> employ quorum sensing (QS)-mediated biofilm formation to accelerate spoilage in salmon. This study constructed a dual-species biofilm model of <em>P. fluorescens</em> and <em>H. alvei</em> to simulate the actual spoilage environment in salmon, and investigated the anti-biofilm potential of penicillin V acylase (<em>Lp</em>PVA) from <em>Lactiplantibacillus plantarum</em> YP4–1-2 against mono- and dual-species systems. The results showed that a more compact dual-species biofilm with elevated levels of AHLs, higher metabolic activity, and greater extracellular polymeric substances (EPS) was observed when <em>P. fluorescens</em> and <em>H. alvei</em> were co-cultured at a ratio of 1:1. In salmon juice, the inhibitory effect of <em>Lp</em>PVA against <em>P. fluorescens</em>, <em>H. alvei</em>, and dual-species biofilm were significantly higher than that in the LB medium, reaching 66.93%, 70.71%, and 63.66% respectively. <em>Lp</em>PVA also significantly reduced AHL levels and suppressed both metabolic activity and EPS production in <em>P. fluorescens</em>, <em>H. alvei</em>, and dual-species biofilms, with inhibitory rates on AHLs of 97.23%, 95.18% and 98.30%, respectively; on metabolic activity of 50.16%, 47.08% and 51.16%, respectively; and on extracellular polysaccharides and proteins of 75.78% and 40.10%, 78.63% and 46.01%, 67.42% and 50.68%, respectively. Additionally, <em>Lp</em>PVA down-regulated QS-related genes and biofilm-related genes to inhibit biofilm formation. The study demonstrates that the interactions between <em>P. fluorescens</em> and <em>H. alvei</em> in a dual-species promoted the formation of complex biofilm structures by increasing AHLs, and their sensitivity to <em>Lp</em>PVA provides a novel strategy for controlling multi-species contamination in aquatic products.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111657"},"PeriodicalIF":5.2,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146062918","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}
This study assessed Escherichia coli as an indicator of antimicrobial resistance (AMR) in retail seafood, integrating microbiological and genomic analyses within a One Health perspective. Overall, E. coli was cultured from 55 (13%) of 422 raw samples from seven seafood categories commonly consumed in Italy. E. coli was detected across multiple seafood types, but particularly in bivalves (23%) and crustaceans (20%). Because these species can accumulate or acquire faecal contaminants from the aquatic environment or along the post-harvest chain, they represent relevant matrices for AMR monitoring. In parallel, we investigated the presence of Extended-β-Lactamase ESBL-, AmpC- and carbapenemase-producing Enterobacteriaceae. Cefotaxime-resistant E. coli isolates were identified at low but relevant frequencies, especially in bivalves, and were characterised phenotypically and by whole-genome sequencing. Most isolates carried clinically important ESBL or AmpC genes, more frequently blaCTX-M-15, often on contigs predicted as plasmid-associated, indicating their potential for horizontal spread. An ESBL-producing Atlantibacter hermannii harbouring blaCTX-M-55 was also recovered from frozen shrimps. Additional AmpC-producing Enterobacteriaceae, including Citrobacter and Enterobacter species, were detected in a subset of samples.
Overall, our findings support the suitability of E. coli as an AMR indicator organism for retail bivalves and crustaceans. The detection of ESBL-producing strains, carrying important plasmid-borne resistance determinants, highlights the need to strengthen AMR surveillance in these seafood commodities.
{"title":"Assessment of Escherichia coli as an indicator of antimicrobial resistance and monitoring of ESBL/AmpC-Producing Enterobacteriaceae in retail seafood commonly consumed in Italy","authors":"Francesca Leoni , Silvia Pieralisi , Elisa Albini , Francesca Romana Massacci , Gabriele Angelico , Serenella Orsini , Carmen Maresca , Eleonora Scoccia , Valeria Michelacci , Paola Chiani , Manuela Marra , Maria Carollo , Francesca Barchiesi , Chiara Francesca Magistrali","doi":"10.1016/j.ijfoodmicro.2026.111650","DOIUrl":"10.1016/j.ijfoodmicro.2026.111650","url":null,"abstract":"<div><div>This study assessed <em>Escherichia coli</em> as an indicator of antimicrobial resistance (AMR) in retail seafood, integrating microbiological and genomic analyses within a One Health perspective. Overall, <em>E. coli</em> was cultured from 55 (13%) of 422 raw samples from seven seafood categories commonly consumed in Italy. <em>E. coli</em> was detected across multiple seafood types, but particularly in bivalves (23%) and crustaceans (20%). Because these species can accumulate or acquire faecal contaminants from the aquatic environment or along the post-harvest chain, they represent relevant matrices for AMR monitoring. In parallel, we investigated the presence of Extended-β-Lactamase ESBL-, AmpC- and carbapenemase-producing <em>Enterobacteriaceae</em>. Cefotaxime-resistant <em>E. coli</em> isolates were identified at low but relevant frequencies, especially in bivalves, and were characterised phenotypically and by whole-genome sequencing. Most isolates carried clinically important ESBL or AmpC genes, more frequently <em>bla</em><sub>CTX-M-15</sub>, often on contigs predicted as plasmid-associated, indicating their potential for horizontal spread. An ESBL-producing <em>Atlantibacter hermannii</em> harbouring <em>bla</em><sub>CTX-M-55</sub> was also recovered from frozen shrimps. Additional AmpC-producing <em>Enterobacteriaceae</em>, including <em>Citrobacter</em> and <em>Enterobacte</em>r species, were detected in a subset of samples.</div><div>Overall, our findings support the suitability of <em>E. coli</em> as an AMR indicator organism for retail bivalves and crustaceans. The detection of ESBL-producing strains, carrying important plasmid-borne resistance determinants, highlights the need to strengthen AMR surveillance in these seafood commodities.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111650"},"PeriodicalIF":5.2,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074453","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}
Pub Date : 2026-01-22DOI: 10.1016/j.ijfoodmicro.2026.111654
Ili Syuhada Mohd Daud , Nor Khaizura Mahmud Ab Rashid , Jon Palmer , Steve Flint
Bacillus cereus is a spore-forming, toxin-producing pathogen that poses a persistent threat to global food safety due to its resistance to heat, disinfectants, and its ability to form biofilms. This review highlights the antimicrobial potential of lemongrass essential oil (LEO) and its major compound, citral, from traditional use to its modern application through nanoemulsion systems. It critically examines how extraction methods affect citral content and bioactivity, and how nanoemulsification enhances LEO's stability, solubility, and efficacy against B. cereus spores and biofilms. Applications include dairy, meat, and fresh produce preservation, where LEO-based coatings, packaging, and sanitizers offer clean-label alternatives to synthetic preservatives. The review also explores regulatory and safety concerns and identifies gaps in sensory effects, long-term stability, and dosing optimization. Overall, citral-rich LEO nanoemulsions represent a promising, sustainable strategy to improve microbial safety and shelf life in food systems affected by B. cereus.
{"title":"From extraction to application: Nanoemulsified lemongrass oil for biofilm and spore control in food preservation","authors":"Ili Syuhada Mohd Daud , Nor Khaizura Mahmud Ab Rashid , Jon Palmer , Steve Flint","doi":"10.1016/j.ijfoodmicro.2026.111654","DOIUrl":"10.1016/j.ijfoodmicro.2026.111654","url":null,"abstract":"<div><div><em>Bacillus cereus</em> is a spore-forming, toxin-producing pathogen that poses a persistent threat to global food safety due to its resistance to heat, disinfectants, and its ability to form biofilms. This review highlights the antimicrobial potential of lemongrass essential oil (LEO) and its major compound, citral, from traditional use to its modern application through nanoemulsion systems. It critically examines how extraction methods affect citral content and bioactivity, and how nanoemulsification enhances LEO's stability, solubility, and efficacy against <em>B. cereus</em> spores and biofilms. Applications include dairy, meat, and fresh produce preservation, where LEO-based coatings, packaging, and sanitizers offer clean-label alternatives to synthetic preservatives. The review also explores regulatory and safety concerns and identifies gaps in sensory effects, long-term stability, and dosing optimization. Overall, citral-rich LEO nanoemulsions represent a promising, sustainable strategy to improve microbial safety and shelf life in food systems affected by <em>B. cereus</em>.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111654"},"PeriodicalIF":5.2,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074359","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}
Pub Date : 2026-01-22DOI: 10.1016/j.ijfoodmicro.2026.111653
Furkan Erdem, Onay Dogan, Hami Alpas
High Hydrostatic Pressure (HHP) is a non-thermal preservation method that enhances microbial safety while maintaining nutritional and sensory attributes. In this study, the inactivation of Escherichia coli O157:H7 in tomato juice was quantified using the Geeraerd primary model, fitted within a Bayesian framework for all pressure–time combinations. Models that would be expected to perform best were pooled and trialed from the primary fits using a regression model. A global (primary–secondary) quadratic secondary model was then applied to describe the dependence of and residual colonies () on pressure, incorporating random effects for each pressure level. Results showed a monotonic increase of with pressure, with the strongest inactivation observed at 450 MPa, while residual populations declined consistently across the pressure domain. Posterior predictive checks confirmed that the Full Geeraerd model provided an accurate description of inactivation kinetics, and that the quadratic secondary structure adequately captured pressure dependence. These findings demonstrate that HHP substantially accelerates microbial inactivation, and that a two-stage Bayesian modeling framework combining primary and secondary models can provide robust predictions to support the optimization of non-thermal food preservation processes.
{"title":"Modeling the inactivation of E. coli O157:H7 (ATCC 43888) in high hydrostatic pressure treated tomato juice","authors":"Furkan Erdem, Onay Dogan, Hami Alpas","doi":"10.1016/j.ijfoodmicro.2026.111653","DOIUrl":"10.1016/j.ijfoodmicro.2026.111653","url":null,"abstract":"<div><div>High Hydrostatic Pressure (HHP) is a non-thermal preservation method that enhances microbial safety while maintaining nutritional and sensory attributes. In this study, the inactivation of <em>Escherichia coli</em> O157:H7 in tomato juice was quantified using the Geeraerd primary model, fitted within a Bayesian framework for all pressure–time combinations. Models that would be expected to perform best were pooled and trialed from the primary fits using a regression model. A global (primary–secondary) quadratic secondary model was then applied to describe the dependence of <span><math><mrow><msub><mrow><mo>log</mo></mrow><mrow><mn>10</mn></mrow></msub><msub><mrow><mi>k</mi></mrow><mrow><mtext>max</mtext></mrow></msub></mrow></math></span> and residual colonies (<span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>R</mi><mi>e</mi><mi>s</mi></mrow></msub></math></span>) on pressure, incorporating random effects for each pressure level. Results showed a monotonic increase of <span><math><msub><mrow><mi>k</mi></mrow><mrow><mtext>max</mtext></mrow></msub></math></span> with pressure, with the strongest inactivation observed at 450 MPa, while residual populations declined consistently across the pressure domain. Posterior predictive checks confirmed that the Full Geeraerd model provided an accurate description of inactivation kinetics, and that the quadratic secondary structure adequately captured pressure dependence. These findings demonstrate that HHP substantially accelerates microbial inactivation, and that a two-stage Bayesian modeling framework combining primary and secondary models can provide robust predictions to support the optimization of non-thermal food preservation processes.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111653"},"PeriodicalIF":5.2,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036089","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}
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