Pub Date : 2025-04-01Epub Date: 2024-11-30DOI: 10.1016/j.fm.2024.104698
Xizi Zhang, Wei Chen, Chengtao Wang
Fungal hyphae self-assemble a variety of cellular macrostates, ranging from suspended mycelium to dense pellets, all inextricably linked to their productivity. In this study, using CRISPR/Cas technology, we constructed a ctnA knockout strain (ΔctnA) and an overexpression strain (A2) so as to investigate the effects of interfering with citrinin biosynthesis on the growth, morphology and pigmentation of M.purpureus. Results indicated that deletion of ctnA in M. purpureus RP2 led to increased mycelium length, delayed conidium formation, and a citrinin content of 22% of the wild-type strain. Conversely, ctnA overexpression in strain A2 resulted in delayed mycelial growth, normal conidium formation, and a citrinin content of 120% compared to the wild-type strain, with minimal effects on pigments content. Notably, the ΔctnA strain formed small, tightly structured pellets (mean diameter 1.2 ± 0.06 mm) and exhibited low citrinin content, promoting pigments production. Our findings suggest a complex interplay between citrinin biosynthesis and morphological development, providing insights for optimizing metabolite production in industrial applications.
{"title":"Regulation of citrinin biosynthesis in Monascus purpureus: Impacts on growth, morphology, and pigments production.","authors":"Xizi Zhang, Wei Chen, Chengtao Wang","doi":"10.1016/j.fm.2024.104698","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104698","url":null,"abstract":"<p><p>Fungal hyphae self-assemble a variety of cellular macrostates, ranging from suspended mycelium to dense pellets, all inextricably linked to their productivity. In this study, using CRISPR/Cas technology, we constructed a ctnA knockout strain (ΔctnA) and an overexpression strain (A2) so as to investigate the effects of interfering with citrinin biosynthesis on the growth, morphology and pigmentation of M.purpureus. Results indicated that deletion of ctnA in M. purpureus RP2 led to increased mycelium length, delayed conidium formation, and a citrinin content of 22% of the wild-type strain. Conversely, ctnA overexpression in strain A2 resulted in delayed mycelial growth, normal conidium formation, and a citrinin content of 120% compared to the wild-type strain, with minimal effects on pigments content. Notably, the ΔctnA strain formed small, tightly structured pellets (mean diameter 1.2 ± 0.06 mm) and exhibited low citrinin content, promoting pigments production. Our findings suggest a complex interplay between citrinin biosynthesis and morphological development, providing insights for optimizing metabolite production in industrial applications.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"104698"},"PeriodicalIF":4.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142817616","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}
The probiotic effects of lactic acid bacteria make them widely used in human and animal breeding industry. However, the presence of oxidative stress during the production and application process can cause bacterial damage or even death, significantly compromising the functionality of probiotics. Despite its potential for broader application scenarios that could provide a more comprehensive understanding of bacteria's internal adaptation strategies, there is a lack of research investigating oxidative stress from the perspective of culture methods. In this study, the tolerance to oxidative stress was compared between bacteria cultivated through solid-state fermentation (SSF) and liquid-state fermentation (LSF), and the physiological and transcriptional disparities between these two bacterial strains were investigated. Additionally, a novel and efficient gene editing method was developed to elucidate the genetic basis underlying these differences in tolerance. The results demonstrated a significantly higher tolerance to oxidative stress in SSF bacteria compared to LSF bacteria, along with a stronger capacity for maintaining intracellular microenvironment stability and the activity of key metabolic enzymes. It is noteworthy that the bacteria from SSF significantly enhance the transport of carbohydrate substances and facilitate intracellular metabolic flow. Gene editing experiments have confirmed the crucial role of genes glpF and glpO in regulating the glycerol metabolism pathway, which is essential for enhancing the tolerance of bacteria from SSF to oxidative stress. Based on these findings, the mechanism underlying the disparity in oxidative stress tolerance resulting from different culture methods has been summarized. Furthermore, investigation into different culture modes has revealed that moderate oxygen levels during cultivation significantly influence variation in bacterial tolerance to oxidative stress. Importantly, these variations are species-specific and depend on the ecological niche distribution of Lactobacilli. These findings elucidate a novel mechanism by which Lacticaseibacillus paracasei Zhang tolerates oxidative stress, and also suggest that distinct cultivation and processing methods should be tailored based on the specific Lactobacilli groups to achieve optimal application effects in production.
{"title":"The investigation of the mechanism underlying variations in oxidative stress tolerance of Lacticaseibacillus paracasei resulting from fermentation methods through endogenous CRISPR-Cas9 editing methodology.","authors":"Pengyu Wu, Yutian Zhang, Qiantong Shan, Ziyang Wang, Shuang Cheng, Laiyou Wang, Bingbing Liu, Wenhuan Li, Zhenmin Chen, Jiancheng Luo, Yunxiang Liang","doi":"10.1016/j.fm.2024.104697","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104697","url":null,"abstract":"<p><p>The probiotic effects of lactic acid bacteria make them widely used in human and animal breeding industry. However, the presence of oxidative stress during the production and application process can cause bacterial damage or even death, significantly compromising the functionality of probiotics. Despite its potential for broader application scenarios that could provide a more comprehensive understanding of bacteria's internal adaptation strategies, there is a lack of research investigating oxidative stress from the perspective of culture methods. In this study, the tolerance to oxidative stress was compared between bacteria cultivated through solid-state fermentation (SSF) and liquid-state fermentation (LSF), and the physiological and transcriptional disparities between these two bacterial strains were investigated. Additionally, a novel and efficient gene editing method was developed to elucidate the genetic basis underlying these differences in tolerance. The results demonstrated a significantly higher tolerance to oxidative stress in SSF bacteria compared to LSF bacteria, along with a stronger capacity for maintaining intracellular microenvironment stability and the activity of key metabolic enzymes. It is noteworthy that the bacteria from SSF significantly enhance the transport of carbohydrate substances and facilitate intracellular metabolic flow. Gene editing experiments have confirmed the crucial role of genes glpF and glpO in regulating the glycerol metabolism pathway, which is essential for enhancing the tolerance of bacteria from SSF to oxidative stress. Based on these findings, the mechanism underlying the disparity in oxidative stress tolerance resulting from different culture methods has been summarized. Furthermore, investigation into different culture modes has revealed that moderate oxygen levels during cultivation significantly influence variation in bacterial tolerance to oxidative stress. Importantly, these variations are species-specific and depend on the ecological niche distribution of Lactobacilli. These findings elucidate a novel mechanism by which Lacticaseibacillus paracasei Zhang tolerates oxidative stress, and also suggest that distinct cultivation and processing methods should be tailored based on the specific Lactobacilli groups to achieve optimal application effects in production.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"104697"},"PeriodicalIF":4.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142817619","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 evaluated the interactions between single or dual-species biofilms formed by dominant spoilage bacteria P. weihenstephanensis and M. caseolyticus isolated from refrigerated, spoilage prepared beef steaks at 4 °C and elucidated the interactive behavior of biofilm development in dual species. In addition, the relationship between biofilm formation capacity and cross-contamination was analyzed by simulating surface to food contact transfer. The results showed that the two species exhibited synergism as biofilms developed, which was the main mode of interaction observed. Under aerobic conditions, Pseudomonas weihenstephanensis and Macrococcus caseolyticus co-cultured for 96 h showed obvious biofilm formation ability, resulting in greater cross-contamination. Scanning electron microscopy and Confocal laser scanning microscopy showed the formation of flattened dense biofilms in the co-culture. The significant increase in Fe content and decrease in siderophore content of the dual-species biofilm as determined by ICP-MS was attributed to respiratory inhibition resulting in a decrease in the transcription of genes regulating the two-component regulatory system of Macrococcus tyrolyticus SrrAB and an increase in the expression of cytoplasmic hydrolase leading to the rupture of the release of hemoglobin to provide a source of iron for P. weihenstephanensis. The increase of heme content in the supernatant of dual-species and the results of RT-qPCR showed that the gene expression of the heme transport system of P. weihenstephanensis was significantly up-regulated and the siderophore gene expression was decreased, which further revealed that P. weihenstephanensis preferentially uses the heme uptake system to take up the iron source provided by M. caseolyticus for P. weihenstephanensis. Overall, our results provide insight into the complex dynamics of biofilms formed by P. weihenstephanensis and M. caseolyticus, emphasizing that the iron reaction pathway may be a key factor influencing the growth of P. weihenstephanensis biofilms, and that these results will provide a theoretical basis for the control of spoilage of refrigerated foods.
{"title":"Interaction and cross-contamination potential of prepared beef steak isolates Pseudomonas weihenstephanensis and Macrococcus caseolyticus in biofilms of dual-species.","authors":"Wendi Zhang, Yunhao Ma, Yong Xie, Xiaoyan Liu, Lijun Tan, Jinsong Zhao, Yongsheng Ni, Zhaoming Wang, Cong Li, Baocai Xu","doi":"10.1016/j.fm.2024.104685","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104685","url":null,"abstract":"<p><p>This study evaluated the interactions between single or dual-species biofilms formed by dominant spoilage bacteria P. weihenstephanensis and M. caseolyticus isolated from refrigerated, spoilage prepared beef steaks at 4 °C and elucidated the interactive behavior of biofilm development in dual species. In addition, the relationship between biofilm formation capacity and cross-contamination was analyzed by simulating surface to food contact transfer. The results showed that the two species exhibited synergism as biofilms developed, which was the main mode of interaction observed. Under aerobic conditions, Pseudomonas weihenstephanensis and Macrococcus caseolyticus co-cultured for 96 h showed obvious biofilm formation ability, resulting in greater cross-contamination. Scanning electron microscopy and Confocal laser scanning microscopy showed the formation of flattened dense biofilms in the co-culture. The significant increase in Fe content and decrease in siderophore content of the dual-species biofilm as determined by ICP-MS was attributed to respiratory inhibition resulting in a decrease in the transcription of genes regulating the two-component regulatory system of Macrococcus tyrolyticus SrrAB and an increase in the expression of cytoplasmic hydrolase leading to the rupture of the release of hemoglobin to provide a source of iron for P. weihenstephanensis. The increase of heme content in the supernatant of dual-species and the results of RT-qPCR showed that the gene expression of the heme transport system of P. weihenstephanensis was significantly up-regulated and the siderophore gene expression was decreased, which further revealed that P. weihenstephanensis preferentially uses the heme uptake system to take up the iron source provided by M. caseolyticus for P. weihenstephanensis. Overall, our results provide insight into the complex dynamics of biofilms formed by P. weihenstephanensis and M. caseolyticus, emphasizing that the iron reaction pathway may be a key factor influencing the growth of P. weihenstephanensis biofilms, and that these results will provide a theoretical basis for the control of spoilage of refrigerated foods.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"104685"},"PeriodicalIF":4.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142817613","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 : 2025-04-01Epub Date: 2024-11-27DOI: 10.1016/j.fm.2024.104689
Paloma Toraño, Alba Martín-García, Albert Bordons, Nicolas Rozès, Cristina Reguant
Lactic acid bacteria (LAB), principally Oenococcus oeni, play crucial roles in wine production, contributing to the transformation of L-malic acid into L-lactic acid during malolactic fermentation (MLF). This fermentation is influenced by different factors, including the initial LAB population and wine stress factors, such as nutrient availability. Yeast mannoproteins can enhance LAB survival in wine. This study explored in model conditions the impact of a commercial mannoprotein extract on MLF dynamics in ten O. oeni strains. The results revealed strain-specific responses in fermentation kinetics and mannoprotein utilization. Mannoprotein addition influenced MLF outcomes, depending on the strain and concentration. The variability in MLF confirmed different technological aptitude of the strains used. The α-mannosidase enzymatic activity was determined and showed higher values in the supernatant than in whole cells. Moreover, α-mannosidase activity varied among strains, suggesting differential regulation in response to fermentation conditions. These findings highlight the importance of understanding mannoprotein interactions with O. oeni for optimizing MLF efficiency and enhancing wine quality. Further research under cellar conditions is needed to evaluate the potential of yeast mannoproteins to promote MLF.
{"title":"Enhancing wine malolactic fermentation: Variable effect of yeast mannoproteins on Oenococcus oeni strains.","authors":"Paloma Toraño, Alba Martín-García, Albert Bordons, Nicolas Rozès, Cristina Reguant","doi":"10.1016/j.fm.2024.104689","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104689","url":null,"abstract":"<p><p>Lactic acid bacteria (LAB), principally Oenococcus oeni, play crucial roles in wine production, contributing to the transformation of L-malic acid into L-lactic acid during malolactic fermentation (MLF). This fermentation is influenced by different factors, including the initial LAB population and wine stress factors, such as nutrient availability. Yeast mannoproteins can enhance LAB survival in wine. This study explored in model conditions the impact of a commercial mannoprotein extract on MLF dynamics in ten O. oeni strains. The results revealed strain-specific responses in fermentation kinetics and mannoprotein utilization. Mannoprotein addition influenced MLF outcomes, depending on the strain and concentration. The variability in MLF confirmed different technological aptitude of the strains used. The α-mannosidase enzymatic activity was determined and showed higher values in the supernatant than in whole cells. Moreover, α-mannosidase activity varied among strains, suggesting differential regulation in response to fermentation conditions. These findings highlight the importance of understanding mannoprotein interactions with O. oeni for optimizing MLF efficiency and enhancing wine quality. Further research under cellar conditions is needed to evaluate the potential of yeast mannoproteins to promote MLF.</p>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"104689"},"PeriodicalIF":4.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142817638","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}
The aim of this study was to develop health-oriented fermented salamis by replacing synthetic preservative (E 252) with dried Sumac (Rhus coriaria) fruit powder (DSFP). The salamis were produced at an industrial scale using meat from the “Suino Nero dei Nebrodi” breed, without adding starter cultures. The experimental design included four different salami productions: CTR, control production without nitrate salt and DSFP; CMC, commercial control production with nitrate salt but without DSFP; EXP1, experimental production without nitrate salt but with DSFP; and EXP2, experimental production with both nitrate salt and DSFP. Plate counts showed that DSFP did not inhibit the growth of lactic acid bacteria (LAB), coagulase-negative staphylococci, and yeasts, all of which reached approximately 7.0 log CFU/g in 45 d ripened salamis. Except for the CTR production, Escherichia coli levels decreased to undetectable amounts at 30 d of ripening. Culture-independent methods identified 16 taxonomic groups, with LAB being the predominant group across all trials, comprising 46.05–81.81 % of relative abundance (RA) in 45 d ripened salamis. Physicochemical analysis indicated that adding DSFP increased antioxidant activity by nearly 30 % and reduced primary lipid oxidation to levels comparable to those achieved with nitrate salt. The addition of DSFP in CMC, EXP1, and EXP2 salamis resulted in an approximate 11 % increase in total terpene aromatic profiles. Sensory evaluation indicated that the addition of DSFP did not impact overall acceptability (p > 0.05). Therefore, incorporating DSFP in fermented meat production offers a viable alternative to the use of synthetic preservatives.
{"title":"Replacing preservative E 252 with powdered dried sumac (Rhus coriaria L.) fruits in “Suino Nero dei Nebrodi” salamis: Effects on microbiological, physicochemical, and antioxidant properties","authors":"Gabriele Busetta , Giuliana Garofalo , Marialetizia Ponte , Marcella Barbera , Antonio Alfonzo , Elena Franciosi , Nicola Francesca , Giuseppe Frusteri , Daniela Piazzese , Adriana Bonanno , Rosario Schicchi , Giancarlo Moschetti , Raimondo Gaglio , Luca Settanni","doi":"10.1016/j.fm.2024.104684","DOIUrl":"10.1016/j.fm.2024.104684","url":null,"abstract":"<div><div>The aim of this study was to develop health-oriented fermented salamis by replacing synthetic preservative (E 252) with dried Sumac (<em>Rhus coriaria</em>) fruit powder (DSFP). The salamis were produced at an industrial scale using meat from the “Suino Nero dei Nebrodi” breed, without adding starter cultures. The experimental design included four different salami productions: CTR, control production without nitrate salt and DSFP; CMC, commercial control production with nitrate salt but without DSFP; EXP1, experimental production without nitrate salt but with DSFP; and EXP2, experimental production with both nitrate salt and DSFP. Plate counts showed that DSFP did not inhibit the growth of lactic acid bacteria (LAB), coagulase-negative staphylococci, and yeasts, all of which reached approximately 7.0 log CFU/g in 45 d ripened salamis. Except for the CTR production, <em>Escherichia coli</em> levels decreased to undetectable amounts at 30 d of ripening. Culture-independent methods identified 16 taxonomic groups, with LAB being the predominant group across all trials, comprising 46.05–81.81 % of relative abundance (RA) in 45 d ripened salamis. Physicochemical analysis indicated that adding DSFP increased antioxidant activity by nearly 30 % and reduced primary lipid oxidation to levels comparable to those achieved with nitrate salt. The addition of DSFP in CMC, EXP1, and EXP2 salamis resulted in an approximate 11 % increase in total terpene aromatic profiles. Sensory evaluation indicated that the addition of DSFP did not impact overall acceptability (<em>p</em> > 0.05). Therefore, incorporating DSFP in fermented meat production offers a viable alternative to the use of synthetic preservatives.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104684"},"PeriodicalIF":4.5,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.fm.2024.104688
Vi D. Pham , Morgan Gerlinsky , Silvio Lettrari , Michael G. Gänzle
Pasta is a staple food in many parts of the world. A bright yellow colour of pasta is preferred by consumers. However, the colour is easily degraded during pasta processing. In a sourdough used for pasta production, we identified the pigmented Fructilactobacillus spp. FUA 3913, which represents a novel species that remains to be described ,and carries genes for the carotenoid-producing enzymes CrtM and CrtN in its genome. HPLC and spectral analysis identified the carotenoid as 4,4′-diaponeurosporene which is also produced by other lactobacilli expressing CrtM and CrtN. The topology of the CrtM/N trees does not match the phylogeny of the organisms, indicating that the enzymes were acquired by horizontal gene transfer. Pigmentation is frequent in insect-associated lactobacilli and lactobacilli that are part of the phyllosphere. Pigmented heterofermentative lactobacilli may enhance the yellow colour of durum semolina pasta by two mechanisms, first, by producing carotenoids and second, by preventing lipoxygenase-mediated degradation of durum carotenoids during dough mixing and extrusion. The comparison of the influence of fermentation with the non-pigmented, homofermentative Lactiplantibacillus plantarum, the non-pigmented heterofermentative Fructilactobacillus sanfranciscensis and the pigmented, heterofermentative Fructilactobacillus spp. FUA3913 indicated that inhibition of lipid oxidation is more relevant for the colour of pasta. In summary, our study provides novel insights into the evolution of C30 carotenoid and ecology of lactobacilli, and documents the use of pigmented lactobacilli to enhance the yellow colour of fermented foods.
{"title":"Evolution and ecology of C30 carotenoid synthesis in Lactobacillaceae and application of pigmented lactobacilli in pasta production","authors":"Vi D. Pham , Morgan Gerlinsky , Silvio Lettrari , Michael G. Gänzle","doi":"10.1016/j.fm.2024.104688","DOIUrl":"10.1016/j.fm.2024.104688","url":null,"abstract":"<div><div>Pasta is a staple food in many parts of the world. A bright yellow colour of pasta is preferred by consumers. However, the colour is easily degraded during pasta processing. In a sourdough used for pasta production, we identified the pigmented <em>Fructilactobacillus</em> spp. FUA 3913, which represents a novel species that remains to be described ,and carries genes for the carotenoid-producing enzymes CrtM and CrtN in its genome. HPLC and spectral analysis identified the carotenoid as 4,4′-diaponeurosporene which is also produced by other lactobacilli expressing CrtM and CrtN. The topology of the CrtM/N trees does not match the phylogeny of the organisms, indicating that the enzymes were acquired by horizontal gene transfer. Pigmentation is frequent in insect-associated lactobacilli and lactobacilli that are part of the phyllosphere. Pigmented heterofermentative lactobacilli may enhance the yellow colour of durum semolina pasta by two mechanisms, first, by producing carotenoids and second, by preventing lipoxygenase-mediated degradation of durum carotenoids during dough mixing and extrusion. The comparison of the influence of fermentation with the non-pigmented, homofermentative <em>Lactiplantibacillus plantarum</em>, the non-pigmented heterofermentative <em>Fructilactobacillus sanfranciscensis</em> and the pigmented, heterofermentative <em>Fructilactobacillus</em> spp. FUA3913 indicated that inhibition of lipid oxidation is more relevant for the colour of pasta. In summary, our study provides novel insights into the evolution of C30 carotenoid and ecology of lactobacilli, and documents the use of pigmented lactobacilli to enhance the yellow colour of fermented foods.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104688"},"PeriodicalIF":4.5,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.fm.2024.104686
Zhenlong Zhou , Ruoxin Chen , Pengzhen Li , Penghui Fan , Lin Ma , Xinyu Cai , Yuchao Hou , Binbin Li , Jianyu Su
Photodynamic inactivation (PDI), a non-thermal sterilization method, has attracted considerable attention due to its broad-spectrum antimicrobial activity, environmental friendliness and cost-effectiveness. Curcumin (Cur), a food-grade photosensitizer, exhibits photodynamic antimicrobial activity based primarily on its efficiency in intracellular accumulation. However, Cur's low water solubility and the barriers presented by the outer membrane of Gram-negative bacteria challenge its ability to penetrate the cytoplasm. Natural borneol (NB), a monoterpene food flavoring agent, has also been shown to improve the efficiency of drug absorption. In this study, we demonstrated that NB significantly improved the cellular uptake of Cur, thereby enhancing its photodynamic bactericidal activity against Gram-negative Escherichia coli (E. coli) ATCC 8739, a potential alternative to enterohemorrhagic E. coli O157:H7. This effect was attributed to NB's ability to disrupt the integrity of the E. coli bacterial membrane, thereby increasing cellular permeability. Transcriptomic analysis further confirmed that NB dysregulated the expression of genes associated with bacterial membrane structure and function in E. coli. Consequently, the increased accumulation of Cur in E. coli led to excessive production of intracellular reactive oxygen species (ROS) upon exposure to 6.5 J/cm2 blue light (BL). These ROS, analyzed biochemically and transcriptionally, primarily disrupted bacterial membrane structure and function, the antioxidant system, and ultimately caused bacterial death. Remarkably, this combined strategy not only reduced E. coli contamination in the tested orange juice, but also preserved its nutritional quality. In conclusion, this research provides an innovative and effective approach to maintaining food safety.
光动力灭活（PDI）是一种非热灭菌方法，因其广谱抗菌活性、环保性和成本效益而备受关注。姜黄素（Cur）是一种食品级光敏剂，其光动力抗菌活性主要基于其在细胞内积累的效率。然而，姜黄素的水溶性较低，而且革兰氏阴性细菌的外膜对其渗透细胞质的能力构成了挑战。天然龙脑（NB）是一种单萜类食品调味剂，也被证明可以提高药物吸收效率。在这项研究中，我们证实 NB 能显著提高 Cur 的细胞吸收率，从而增强其对革兰氏阴性大肠杆菌（E. coli）ATCC 8739（肠出血性大肠杆菌 O157:H7 的潜在替代物）的光动力杀菌活性。这种效应归因于 NB 能够破坏大肠杆菌细菌膜的完整性，从而增加细胞的通透性。转录组分析进一步证实，NB 使大肠杆菌中与细菌膜结构和功能相关的基因表达失调。因此，在暴露于 6.5 J/cm2 蓝光（BL）时，大肠杆菌中 Cur 的积累增加，导致细胞内活性氧（ROS）产生过多。通过生化和转录分析，这些 ROS 主要破坏了细菌的膜结构和功能以及抗氧化系统，并最终导致细菌死亡。值得注意的是，这种综合策略不仅减少了测试橙汁中的大肠杆菌污染，还保持了其营养品质。总之，这项研究为维护食品安全提供了一种创新而有效的方法。
{"title":"Natural borneol improves cellular uptake of curcumin to enhance its photodynamic bactericidal activity against Escherichia coli ATCC 8739","authors":"Zhenlong Zhou , Ruoxin Chen , Pengzhen Li , Penghui Fan , Lin Ma , Xinyu Cai , Yuchao Hou , Binbin Li , Jianyu Su","doi":"10.1016/j.fm.2024.104686","DOIUrl":"10.1016/j.fm.2024.104686","url":null,"abstract":"<div><div>Photodynamic inactivation (PDI), a non-thermal sterilization method, has attracted considerable attention due to its broad-spectrum antimicrobial activity, environmental friendliness and cost-effectiveness. Curcumin (Cur), a food-grade photosensitizer, exhibits photodynamic antimicrobial activity based primarily on its efficiency in intracellular accumulation. However, Cur's low water solubility and the barriers presented by the outer membrane of Gram-negative bacteria challenge its ability to penetrate the cytoplasm. Natural borneol (NB), a monoterpene food flavoring agent, has also been shown to improve the efficiency of drug absorption. In this study, we demonstrated that NB significantly improved the cellular uptake of Cur, thereby enhancing its photodynamic bactericidal activity against Gram-negative <em>Escherichia coli</em> (<em>E. coli</em>) ATCC 8739, a potential alternative to enterohemorrhagic <em>E. coli</em> O157:H7. This effect was attributed to NB's ability to disrupt the integrity of the <em>E. coli</em> bacterial membrane, thereby increasing cellular permeability. Transcriptomic analysis further confirmed that NB dysregulated the expression of genes associated with bacterial membrane structure and function in <em>E. coli</em>. Consequently, the increased accumulation of Cur in <em>E. coli</em> led to excessive production of intracellular reactive oxygen species (ROS) upon exposure to 6.5 J/cm<sup>2</sup> blue light (BL). These ROS, analyzed biochemically and transcriptionally, primarily disrupted bacterial membrane structure and function, the antioxidant system, and ultimately caused bacterial death. Remarkably, this combined strategy not only reduced <em>E. coli</em> contamination in the tested orange juice, but also preserved its nutritional quality. In conclusion, this research provides an innovative and effective approach to maintaining food safety.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104686"},"PeriodicalIF":4.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699201","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 : 2024-11-20DOI: 10.1016/j.fm.2024.104683
Zhen Li , Yu Wang , Rui Li , Yuxin Hu , Xin Wang , Wen Li , Yuanzhi Shao
Microbial communities, both on the surface and within fruit, play a crucial role in reducing postharvest diseases and maintaining fruit quality. This study investigated the effects of co-culture fermentation supernatant of Debaryomyces hansenii (Y) and Bacillus atrophaeus (T) on disease control and quality preservation of postharvest litchi fruit, while exploring the underlying mechanisms through microbiome profiling. The results indicated that Y + T treatment not only reduced decay percentage, weight loss, and pH increase but also preserved the pericarp cell integrity and reduced the lignin accumulation. Additionally, it delayed changes in firmness, chroma value, anthocyanin content, and the contents of soluble sugar, protein, and vitamin C during storage. High-throughput sequencing revealed significant differences in the diversity and richness of bacterial and fungal species between the control and Y + T-treated fruit. The Y + T treatment maintained microbial diversity, promoted the growth and metabolism of potentially beneficial genera (e.g., Cyanobacteria, Bacillus, Paenibacillus, Hanseniaspora, Pichia), and suppressed pathogenic genera (e.g., Xylaria, Lasiodiplodia, Gibberella, Fusarium). These changes contributed to promote disease resistance and improve postharvest quality of litchi fruit. This study provides valuable insights into how microbial antagonists can regulate postharvest diseases and sets the groundwork for developing beneficial microbial consortia to enhance the postharvest safety and commercial value of litchi fruit.
水果表面和内部的微生物群落在减少采后病害和保持水果品质方面发挥着至关重要的作用。本研究探讨了汉逊德巴氏酵母菌（Y）和萎凋酸芽孢杆菌（T）共培养发酵上清液对采后荔枝果实病害防治和品质保持的影响，同时通过微生物组图谱分析探索其潜在机制。结果表明，Y + T 处理不仅降低了腐烂率、重量损失和 pH 值升高，还保持了果皮细胞的完整性，减少了木质素积累。此外，它还延缓了贮藏过程中果实硬度、色度值、花青素含量以及可溶性糖、蛋白质和维生素 C 含量的变化。高通量测序显示，对照组和 Y + T 处理组水果中细菌和真菌物种的多样性和丰富度存在显著差异。Y + T 处理保持了微生物的多样性，促进了潜在有益菌属（如蓝细菌属、芽孢杆菌属、担子菌属、担子菌属）的生长和新陈代谢，抑制了致病菌属（如木霉菌属、疫霉菌属、吉贝拉菌属、镰刀菌属）的生长和新陈代谢。这些变化有助于提高荔枝果的抗病性和采后品质。这项研究为了解微生物拮抗剂如何调节采后病害提供了宝贵的见解，并为开发有益微生物联合体以提高荔枝果采后安全性和商业价值奠定了基础。
{"title":"Co-culture fermentation of Debaryomyces hansenii and Bacillus atrophaeus alleviates quality deterioration of litchi fruit by ameliorating microbial community diversity and composition","authors":"Zhen Li , Yu Wang , Rui Li , Yuxin Hu , Xin Wang , Wen Li , Yuanzhi Shao","doi":"10.1016/j.fm.2024.104683","DOIUrl":"10.1016/j.fm.2024.104683","url":null,"abstract":"<div><div>Microbial communities, both on the surface and within fruit, play a crucial role in reducing postharvest diseases and maintaining fruit quality. This study investigated the effects of co-culture fermentation supernatant of <em>Debaryomyces hansenii</em> (Y) and <em>Bacillus atrophaeus</em> (T) on disease control and quality preservation of postharvest litchi fruit, while exploring the underlying mechanisms through microbiome profiling. The results indicated that Y + T treatment not only reduced decay percentage, weight loss, and pH increase but also preserved the pericarp cell integrity and reduced the lignin accumulation. Additionally, it delayed changes in firmness, chroma value, anthocyanin content, and the contents of soluble sugar, protein, and vitamin C during storage. High-throughput sequencing revealed significant differences in the diversity and richness of bacterial and fungal species between the control and Y + T-treated fruit. The Y + T treatment maintained microbial diversity, promoted the growth and metabolism of potentially beneficial genera (e.g., <em>Cyanobacteria</em>, <em>Bacillus</em>, <em>Paenibacillus</em>, <em>Hanseniaspora</em>, <em>Pichia</em>), and suppressed pathogenic genera (e.g., <em>Xylaria</em>, <em>Lasiodiplodia</em>, <em>Gibberella</em>, <em>Fusarium</em>). These changes contributed to promote disease resistance and improve postharvest quality of litchi fruit. This study provides valuable insights into how microbial antagonists can regulate postharvest diseases and sets the groundwork for developing beneficial microbial consortia to enhance the postharvest safety and commercial value of litchi fruit.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104683"},"PeriodicalIF":4.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698752","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 : 2024-11-20DOI: 10.1016/j.fm.2024.104682
Batlah Almutairi , Mary T. Fletcher , Hung Trieu Hong , Anran Dong , Mark S. Turner , Yasmina Sultanbawa
One promising method for the detoxification of Aflatoxin M1 (AFM1) involves the use of probiotic bacteria combined with prebiotics. This approach is both safe and cost-effective, while also offering additional health benefits. The objective of this study was to investigate the capacity of Lactococcus lactis 537 (Lc. Lactis 537) to bind AFM1 in milk and phosphate-buffered saline (PBS), either in the presence or absence of inulin or Kakadu plum fruit powder (KP), which are prebiotic substances. Lc. Lactis 537 was incubated for 0, 1, 2, and 24 h at 30 °C, with or without inulin or KP, to assess its ability to bind and reduce AFM1 levels. The concentration of AFM1 was determined using liquid chromatography-mass spectrometry (LC-MS9) during the different incubation periods. The results demonstrated that Lc. Lactis 537 significantly reduced the initial concentration of AFM1 in both milk and PBS after 24 h of incubation. Moreover, the presence of inulin or KP enhanced the binding and reduction capacity of Lc. Lactis 537. This suggests that the synbiotic effect where probiotic bacteria like Lc. Lactis work in synergy with prebiotics such as inulin or KP could play a critical role in the removal of AFM1 from contaminated substances. In conclusion, the synbiotic of Lc. Lactis 537 with inulin or KP represents a promising biological approach for AFM1 detoxification, and further research is warranted to explore its potential applications in food safety.
{"title":"Assessment of the ability of Lactococcus lactis 537 to bind aflatoxin M1 in the presence of inulin and Terminalia ferdinandiana (Kakadu plum)","authors":"Batlah Almutairi , Mary T. Fletcher , Hung Trieu Hong , Anran Dong , Mark S. Turner , Yasmina Sultanbawa","doi":"10.1016/j.fm.2024.104682","DOIUrl":"10.1016/j.fm.2024.104682","url":null,"abstract":"<div><div>One promising method for the detoxification of Aflatoxin M1 (AFM1) involves the use of probiotic bacteria combined with prebiotics. This approach is both safe and cost-effective, while also offering additional health benefits. The objective of this study was to investigate the capacity of <em>Lactococcus lactis</em> 537 (<em>Lc. Lactis</em> 537) to bind AFM1 in milk and phosphate-buffered saline (PBS), either in the presence or absence of inulin or Kakadu plum fruit powder (KP), which are prebiotic substances. <em>Lc. Lactis</em> 537 was incubated for 0, 1, 2, and 24 h at 30 °C, with or without inulin or KP, to assess its ability to bind and reduce AFM1 levels. The concentration of AFM1 was determined using liquid chromatography-mass spectrometry (LC-MS9) during the different incubation periods. The results demonstrated that <em>Lc. Lactis</em> 537 significantly reduced the initial concentration of AFM1 in both milk and PBS after 24 h of incubation. Moreover, the presence of inulin or KP enhanced the binding and reduction capacity of <em>Lc. Lactis</em> 537. This suggests that the synbiotic effect where probiotic bacteria like <em>Lc. Lactis</em> work in synergy with prebiotics such as inulin or KP could play a critical role in the removal of AFM1 from contaminated substances. In conclusion, the synbiotic of <em>Lc. Lactis</em> 537 with inulin or KP represents a promising biological approach for AFM1 detoxification, and further research is warranted to explore its potential applications in food safety.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104682"},"PeriodicalIF":4.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.fm.2024.104681
Kui Liu , Yuhan Liu , Yangzhi Liu , Xinhua Huang , Yanhong Jia , Lizhu Ji , Shiping Tian , Tong Chen
Botrytis cinerea is a major cause of postharvest rot in fresh fruits and vegetables worldwide. Consequently, the pursuit of environmentally friendly and efficient alternatives to fungicides has emerged as a hot spot of research. In this study, it was found that dictamnine (DIC, 4-methoxyfuro [2,3-β] quinoline), an active ingredient from Dictamnus dasycarpus Turcz, efficiently inhibited spore germination and mycelial growth of B. cinerea, alleviated the development of lesions caused by B. cinerea on postharvest apples, kiwifruits, cherry tomatoes and strawberries in a dose-dependent manner. RNA sequencing analysis followed by Gene Ontology (GO) term enrichment revealed that functional genes related to cell membrane function were significantly enriched, while most genes associated with ergosterol biosynthesis were down-regulated. Molecular docking indicated that DIC bound to the rate-limiting enzymes BcERG1 (squalene monooxygenase) and BcERG11 (Lanosterol 14-alpha demethylase) at −7.1 and −7.2 kcal mol−1, respectively. Additionally, it was observed that the application of DIC led to a decrease in ergosterol content, which compromised membrane integrity and normal membrane potential. Interestingly, exogenous ergosterol addition partially restored the inhibitory effect of DIC on the germination of B. cinerea spores and the lesion development on apple fruit. Taken together, these results indicate the potential for utilizing DIC as a promising antifungal substitute for controlling gray mold in postharvest fruit.
{"title":"Suppression of ergosterol biosynthesis by dictamnine confers resistance to gray mold on harvested fruit","authors":"Kui Liu , Yuhan Liu , Yangzhi Liu , Xinhua Huang , Yanhong Jia , Lizhu Ji , Shiping Tian , Tong Chen","doi":"10.1016/j.fm.2024.104681","DOIUrl":"10.1016/j.fm.2024.104681","url":null,"abstract":"<div><div><em>Botrytis cinerea</em> is a major cause of postharvest rot in fresh fruits and vegetables worldwide. Consequently, the pursuit of environmentally friendly and efficient alternatives to fungicides has emerged as a hot spot of research. In this study, it was found that dictamnine (DIC, 4-methoxyfuro [2,3-β] quinoline), an active ingredient from <em>Dictamnus dasycarpus</em> Turcz, efficiently inhibited spore germination and mycelial growth of <em>B. cinerea</em>, alleviated the development of lesions caused by <em>B. cinerea</em> on postharvest apples, kiwifruits, cherry tomatoes and strawberries in a dose-dependent manner. RNA sequencing analysis followed by Gene Ontology (GO) term enrichment revealed that functional genes related to cell membrane function were significantly enriched, while most genes associated with ergosterol biosynthesis were down-regulated. Molecular docking indicated that DIC bound to the rate-limiting enzymes BcERG1 (squalene monooxygenase) and BcERG11 (Lanosterol 14-alpha demethylase) at −7.1 and −7.2 kcal mol<sup>−1</sup>, respectively. Additionally, it was observed that the application of DIC led to a decrease in ergosterol content, which compromised membrane integrity and normal membrane potential. Interestingly, exogenous ergosterol addition partially restored the inhibitory effect of DIC on the germination of <em>B. cinerea</em> spores and the lesion development on apple fruit. Taken together, these results indicate the potential for utilizing DIC as a promising antifungal substitute for controlling gray mold in postharvest fruit.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":"127 ","pages":"Article 104681"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698750","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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