Food microbiology最新文献

{"title":"Current state, challenges and future orientations of the applications of lactic acid bacteria exopolysaccharide in foods","authors":"","doi":"10.1016/j.fm.2024.104678","DOIUrl":"10.1016/j.fm.2024.104678","url":null,"abstract":"<div><div>In the quest for a balanced diet and better health, the global shift towards nutrient-dense foods highlights the multiple roles of lactic acid bacteria exopolysaccharides (LAB-EPS) in improving food quality and health. This paper offers a comprehensive survey of LAB-EPS, focusing on their classification, biosynthesis pathways and application in the food industry, from dairy products to bakery products and meat. It highlights the impact of LAB-EPS on the texture and sensory qualities of food. Despite their promising prospects, these polysaccharides face various application challenges in the food industry. These include variability in EPS production among LAB strains, complexity in structure-function relationships, and limited understanding of their health benefits. In order to address these issues, the review identifies and suggests future research directions to optimize the production of LAB-EPS, elucidating their health benefit mechanisms, and expanding their application scope. In summary, this review aims to contribute to advance innovation and progress in the food industry by developing healthier food options and deepening the understanding of LAB-EPS in promoting human health.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571453","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":"Enzymatic degradation of mycotoxin patulin by a short-chain dehydrogenase/reductase from Bacillus subtilis and its application in apple juice","authors":"","doi":"10.1016/j.fm.2024.104676","DOIUrl":"10.1016/j.fm.2024.104676","url":null,"abstract":"<div><div>Patulin (PAT), a notorious mycotoxin widely found in fruits and their derived products, poses serious health risks to humans and animals due to its high toxicity. Biodegradation based on microbial enzymes has shown broad application prospects in controlling PAT contamination due to its environmental friendliness, high efficiency, strong specificity, and mild conditions of action. <em>Bacillus subtilis</em> is a cosmopolitan probiotic bacterium with an extensive enzymatic profile, which could serve as a valuable resource for the effective production of a range of enzymes utilized in various industrial processes and production applications. In this work, we demonstrated that a short-chain dehydrogenase/reductase from <em>B. subtilis</em> (<em>Bs</em>SDR) that can effectively convert PAT to the non-toxic E-ascladiol. Multiple sequence alignment results revealed that <em>Bs</em>SDR displayed less than 30% identity with the previously reported PAT-degrading enzymes, indicating that it is a novel PAT-degrading enzyme. <em>Bs</em>SDR exhibited a powerful PAT-degrading ability and strong PAT tolerance, as it was capable of degrading over 95% of PAT at initial concentrations of 50–500 μM. In addition, <em>Bs</em>SDR exhibited the highest activity at pH 8.0 and 40 °C, and retained more than 60% residual activity after incubation at 40 °C for 3 h, indicating a remarkable thermostability of <em>Bs</em>SDR. Molecular docking and site-directed mutagenesis indicated that the catalytic triad formed by the residues (S, Y, and K) was the key for short-chain dehydrogenase/reductase activity and this conserved catalytic mechanism was followed in <em>Bs</em>SDR catalysis. More importantly, <em>Bs</em>SDR is able to eliminate 83.61% of PAT in apple juice without compromising its quality during the biodegradation process. These results suggest that <em>Bs</em>SDR may serve as a promising detoxification agent for the degradation of PAT in food processing.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593902","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":"pLM33 provides tolerance of persistent Listeria monocytogenes ST5 to various stress conditions and also enhances its virulence","authors":"","doi":"10.1016/j.fm.2024.104675","DOIUrl":"10.1016/j.fm.2024.104675","url":null,"abstract":"<div><div><em>Listeria monocytogenes</em> is a major foodborne pathogen. In our previous study, we found that <em>L. monocytogenes</em> ST5 and ST121 strains were dominant in two food plants of Shanghai. Genetic characterization revealed that the environmental tolerance of these strains was attributable to the plasmids pLM33 and pLM5578. To further evaluate the function of <em>L. monocytogenes</em> plasmids<em>,</em> we selected ST5 and ST121 wild-type strains, and used their plasmid-cured strains as controls to conduct tolerance tests. In addition, we analyzed 108 <em>L. monocytogenes</em> strains isolated from four major food categories in Shanghai. Our results showed that compared with the plasmid-cured strain, the ST5 strain carrying pLM33 showed higher tolerance to environmental stress conditions, including low acid, high salt, oxidizing, and high-temperature conditions; as well as higher virulence. Furthermore, we found that the plasmid carriage rate of food isolates was 97.22%, with the highest carriage rate of 68.57% for pLM5578, followed by 24.76% for pLM33. Notably, all <em>L. monocytogenes</em> ST5 isolates from ready-to-eat food products (n = 11) carried plasmids, suggesting that contamination of these food products may pose a serious risk to human health. In summary, the results of this study broaden our understanding regarding the role of <em>L. monocytogenes</em> plasmids in stress responses.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555031","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":"Improving ready-to-eat meat safety: Evaluating the bacterial-inactivation efficacy of microplasma-based far-UVC light treatment of food-contact surfaces and deli turkey breast","authors":"","doi":"10.1016/j.fm.2024.104674","DOIUrl":"10.1016/j.fm.2024.104674","url":null,"abstract":"<div><div>The safety of ready-to-eat (RTE) deli meats, especially those sliced in retail establishments, may be improved by light-based surface decontamination. Conventional 254 nm ultraviolet-C (UVC) systems have strong germicidal effects but pose human-health hazards that make them unsuitable for retail use. This study therefore explores the efficacy of microplasma-based 222 nm far-UVC lamps as a safer alternative for decontaminating liquid buffer, two common food-contact surfaces (polyethylene terephthalate and stainless steel), and RTE turkey breast. In all three non-meat cases, the system achieved approximately 5-log reductions of both <em>Listeria monocytogenes</em> and <em>Salmonella</em> Typhimurium. The system also caused a 1.3-log reduction of <em>L. monocytogenes</em> and a 1-log reduction of <em>S.</em> Typhimurium on turkey breast at the highest tested dose of 786.3 mJ/cm². Color is a key quality indicator for RTE meat consumers, and treatment caused no significant change in L∗, a∗, or b∗ color values (<em>p</em> &gt; 0.05) until doses reached 224.7 mJ/cm². However, higher doses could lead to statistically significant color changes. Given that far-UVC light has been deemed human-safe by other studies, the proposed system has considerable potential to improve RTE food-related safety in retail establishments, even when consumers and workers are present.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555030","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}

{"title":"Using plasma-activated water for decontamination of Salmonella spp. on common building surfaces in poultry houses","authors":"","doi":"10.1016/j.fm.2024.104673","DOIUrl":"10.1016/j.fm.2024.104673","url":null,"abstract":"<div><div>Plasma-activated water (PAW) has been shown to have antimicrobial properties, making it a promising tool for surface decontamination. This study evaluated the ability of PAW generated from high voltage atmospheric cold plasma to remove <em>Salmonella</em> from common surfaces (stainless steel (SS), polyvinyl chloride (PVC), concrete, and wood) found in poultry houses. PAW was generated by exposing distilled water to atmospheric cold plasma in 80% humid air at 90 kV and 60 Hz for 30 min. The resulting PAW contained 1120 ppm of nitrate and 1370 ppm of hydrogen peroxide, with a pH of 1.83. PAW was then applied to coupons of SS, PVC, wood, and concrete surfaces inoculated with 7–8 log₁₀ CFU of cocktail of <em>Salmonella</em> spp. (<em>S.</em> Typhimurium, <em>S</em>. Newport, <em>S.</em> Montevideo, and <em>S.</em> Enteritidis). PAW effectively reduced <em>Salmonella</em> levels on SS and PVC surfaces to below the detection limit within 30 s. On wood surfaces, a longer treatment time of 7.5 min was required to achieve a maximum reduction of 2.63 log₁₀ CFU, likely due to the porosity of the wood limiting PAW contact with the bacteria. On concrete surfaces, the reduction in Salmonella levels was only 0.98 log₁₀ CFU. This was likely due to the greater surface roughness and high alkalinity, which neutralized the PAW species.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536294","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":"Microbiological analysis of donor human milk over seven years from the Hearts Milk Bank (United Kingdom)","authors":"","doi":"10.1016/j.fm.2024.104661","DOIUrl":"10.1016/j.fm.2024.104661","url":null,"abstract":"<div><div>When maternal milk is unavailable, donor human milk (DHM) from human milk banks (HMBs) is the optimal alternative, as recommended by the World Health Organisation. The microbiota of DHM could contain opportunistic pathogens, which means rigorous microbiological screening for DHM, prior to pasteurisation, is recommended to safeguard recipients. Here, an analysis of 6863 DHM samples from 1419 donors at the Hearts Milk Bank between 2017 and 2023 showed approximately 70.1% of samples exhibited a total viable count (TVC) between 10³-10⁵ CFU/mL, while 18.3% yielded no growth; 11.5% of samples exceeded the 10⁵ CFU/mL threshold. <em>Staphylococcus</em> was the most prevalent genus, with <em>S. epidermidis</em> found in 61.5% of samples. A significant (<em>p</em> &lt; 0.05) negative co-occurrence was observed between <em>S. epidermidis</em> and Gram-negative opportunistic pathogens. Overall, 16.8% of DHM samples failed to meet UK microbiological screening criteria, with 68.3% of these failures due to exceeding TVC thresholds. <em>S. epidermidis</em> accounted for approximately 10.2% of the total failed samples. The majority of DHM samples met the current microbiological criteria specified in the National Institute for Health and Care Excellence (NICE) clinical guidance (CG93), “Donor milk banks: service operation”. The core species in DHM reflects microorganisms typically found on the skin. These findings highlight that the current UK thresholds and criteria could potentially be modified to increase the available supply of DHM without increasing microbiological risk.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536293","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}

{"title":"ELIME-IMS hybrid assay for Salmonella detection in swine mesenteric lymph nodes at slaughterhouse","authors":"","doi":"10.1016/j.fm.2024.104659","DOIUrl":"10.1016/j.fm.2024.104659","url":null,"abstract":"<div><div><em>Salmonella</em> contamination in pig slaughterhouses is linked to infection rate on farms. Accurate diagnosis in heavy pigs relies on isolating pathogens from the gut wall or lymph nodes. A key technique is Immunocapture using Magnetic Beads (IMS), which purifies target bacteria from <em>Salmonella</em> enrichment broths. This is followed by an Enzyme-Linked Immunomagnetic Electrochemical (ELIME) assay for rapid detection. In our study, we developed an ELIME-IMS hybrid assay to detect <em>Salmonella</em> in swine mesenteric lymph nodes (MNL), involving a clean-up with N-acetylcysteine and centrifugation. Detection limits for <em>S.</em> Typhimurium and <em>S.</em> Derby were estimated at 2.80 and 3.52 Log CFU/ml, respectively. We analysed 103 MNL samples from a northern Italy slaughterhouse. Additionally, we examined 15 carcass swabs. Both the ELIME assay and the IMS-based culture method showed strong agreement with the ISO 6579–1:2017 method, especially after 20 h of enrichment (89.47% concordance). The clean-up step significantly influenced the results, as samples processed without it showed higher variability. A logistic regression model indicated high classification accuracy for negative samples using ELIME values. The ELIME-IMS assay facilitates rapid <em>Salmonella</em> screening and isolation in swine mesenteric lymph nodes.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444768","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}

{"title":"Impact of pre-exposure stress on the growth and viability of Lactobacillus acidophilus in regular, buriti pulp and orange byproduct fermented milk products","authors":"","doi":"10.1016/j.fm.2024.104660","DOIUrl":"10.1016/j.fm.2024.104660","url":null,"abstract":"<div><div>The loss of probiotics viability in yogurts and fermented milk is a significant challenge in producing yogurt and fermented milk. Thus, pre-exposure of probiotics to stress conditions can be a viable alternative to increase the probiotic viability. Moreover, the use of fruit pulp and agro-industrial residues in these products has demonstrated promising results in promoting growth and improving the viability of probiotics. Thus, this study aimed to evaluate the effects of pre-exposure to acid, oxidative and osmotic stress on the growth and viability of <em>Lactobacillus acidophilus</em> in yogurts and naturally fermented milk containing buriti (<em>Mauritia flexuosa</em> Mart.) pulp or orange byproduct. <em>L. acidophilus</em> was individually pre-exposed to acid, oxidative, and osmotic stress and used in the production of yogurts and fermented milk to determine both the acidification profile and growth of the cultures. Furthermore, during cold storage, the post-acidification profiles and viability of microbial cultures added to the yogurts and fermented milk were monitored. Results showed that pre-exposure to stress conditions influenced the growth parameters as the growth rate (μ) and lag phase (λ) of <em>L. acidophilus</em> and the starter cultures of <em>S. thermophilus</em> and <em>L. delbrueckii</em> subsp. <em>bulgaricus</em>. Moreover, an increase in the viability of <em>L. acidophilus</em> - pre-exposed to acid stress - was observed on the 21st day of storage of natural yogurts containing orange byproduct compared with non-stressful conditions. This study reports new data on the growth of probiotic cultures pre-exposed to stress conditions in products added of pulps and agro-industrial residues, which have not yet been shown in the literature.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442242","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":"Biocontrol potential of Streptomyces sp. N2 against green and blue mold disease in postharvest navel orange and the action mechanism","authors":"","doi":"10.1016/j.fm.2024.104658","DOIUrl":"10.1016/j.fm.2024.104658","url":null,"abstract":"<div><div>The objective of this study was to provide a promising alternative to chemical fungicides for management of postharvest citrus decay, thereby promoting sustainable citrus fruit production. The postharvest decay of citrus fruit caused by <em>Penicillium digitatum</em> and <em>Penicillium italicum</em> results in substantial economic losses in citrus industry worldwide. With growing fungal resistance issues in <em>P. digitatum</em> and <em>P. italicum</em>, there is an urgent need for searching new methods to address above problems in a safe and environmentally friendly way. <em>Streptomyces</em> sp. N2, a new species from <em>Streptomyces</em> genus, exhibits significant antagonistic activity against <em>Rhizoctonia solani</em>. However, its biocontrol efficacy against postharvest decay caused by <em>P. digitatum</em> and <em>P. italicum</em> and its action mechanism remain unknown. In this study, <em>Streptomyces</em> sp. N2 was found to have significant potential in controlling green and blue mold diseases in postharvest navel oranges. Moreover, the action mechanism of <em>Streptomyces</em> sp. N2 against both <em>P. italicum</em> and <em>P. digitatum</em> was elucidated. On the one hand, <em>Streptomyces</em> sp. N2 stimulated fruit resistance to fight against invading fungal pathogens. It significantly reduced ROS content in navel orange upon the infection of mold disease, increased the production of defense-related enzymes including peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) and pathogenesis-related proteins of chitinase and β-1,3-glucanase. On the other hand, <em>Streptomyces</em> sp. N2 secreted bioactive substances to inhibit the growth of <em>P. italicum</em> and <em>P. digitatum</em> so as to prevent the development of postharvest decay. The bioactive substances secreted by <em>Streptomyces</em> sp. N2 significantly inhibited the spore germination and mycelial growth and led to microstructural damages to the cell wall and membrane, ROS burst, and mitochondrial dysfunction in both <em>P. italicum</em> and <em>P. digitatum</em>. This study provides a theoretical reference and application potential for the biological control of <em>Streptomyces</em> sp. N2 on green and blue mold diseases.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432200","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":"Interaction between a Lactococcus lactis autochthonous starter and a raw goat milk microbial community during long-term backslopping","authors":"","doi":"10.1016/j.fm.2024.104656","DOIUrl":"10.1016/j.fm.2024.104656","url":null,"abstract":"<div><div>Traditional cheesemaking processes often involve backslopping practice. However, over successive inoculations, acidification deficiencies may arise. In such cases, adding a starter is recommended to restore the ecosystem stability. This study examines the impact of an autochthonous starter composed of three <em>Lactococcus lactis</em> strains on a raw goat milk microbial community during their evolution. Bacterial composition and technological features (acidification and aroma) were analyzed during communities’ evolution over 800 generations. 16S rRNA gene metabarcoding showed that <em>Lactococcus lactis</em> strains predominated. The raw goat milk community acidification capacities varied early in the evolution and then remained stable. Adding the <em>L. lactis</em> starter to this community stabilized the ecosystem from the beginning of the evolution. The acetoin production was associated with the starter presence, consistent with the establishment of the <em>diacetylatis</em> biovar strain from the starter in the raw goat milk community throughout the evolution. Increased or decreased production of some volatile organic compounds when the starter was added revealed a specific aroma footprint due to interactions between the two communities. This study showed that adding a starter could help to achieve the maximum acidification rate from the early inoculation cycles and could significantly modify the aroma profile during long-term backslopping.</div></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444767","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}