Food microbiology最新文献

{"title":"Prevalence and types of methicillin-resistant Staphylococcus aureus (MRSA) in meat and meat products from retail outlets and in samples of animal origin collected in farms, slaughterhouses and meat processing facilities. A review","authors":"Camino González-Machado ,&nbsp;Carlos Alonso-Calleja ,&nbsp;Rosa Capita","doi":"10.1016/j.fm.2024.104580","DOIUrl":"10.1016/j.fm.2024.104580","url":null,"abstract":"<div><p>Methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) is a frequent cause of nosocomial and community infections, in some cases severe and difficult to treat. In addition, there are strains of MRSA that are specifically associated with food-producing animals. For this reason, in recent years special attention has been paid to the role played by foodstuffs of animal origin in infections by this microorganism. With the aim of gaining knowledge on the prevalence and types of MRSA in meat and meat products, a review was undertaken of work published on this topic since 2001, a total of 259 publications, 185 relating to meat samples from retail outlets and 74 to samples of animal origin collected in farms, slaughterhouses and meat processing facilities. Strains of MRSA were detected in 84.3% reports (156 out of 185) from retail outlets and 86.5% reports (64 out of 74) from farms, slaughterhouses and meat processing facilities, although in most of the research this microorganism was detected in under 20% of samples from retail outlets, and under 10% in those from farms, slaughterhouses and meat processing facilities. The meat and meat products most often contaminated with MRSA were pork and chicken. In addition to the <em>me</em>cA gene, it is crucial to take into consideration the <em>mec</em>B and <em>mec</em>C genes, so as to avoid misidentification of strains as MSSA (methicillin-susceptible <em>Staphylococcus aureus</em>). The great variety of methods used for the determination of MRSA highlights the need to develop a standardized protocol for the study of this microorganism in foods.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0740002024001187/pdfft?md5=1330cd9f5f4fa3b2915cb3bf62b6bc94&pid=1-s2.0-S0740002024001187-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141278730","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":"Species-level understanding of the bacterial community in Daqu based on full-length 16S rRNA gene sequences","authors":"Pei-Jie Han ,&nbsp;Liang Song ,&nbsp;Zhang Wen ,&nbsp;Hai-Yan Zhu ,&nbsp;Yu-Hua Wei ,&nbsp;Jian-Wei Wang ,&nbsp;Mei Bai ,&nbsp;Lu-Jun Luo ,&nbsp;Ju-Wei Wang ,&nbsp;Shen-Xi Chen ,&nbsp;Xiao-Long You ,&nbsp;Da-Yong Han ,&nbsp;Feng-Yan Bai","doi":"10.1016/j.fm.2024.104566","DOIUrl":"10.1016/j.fm.2024.104566","url":null,"abstract":"<div><p>Daqu is used as the fermentation starter of Baijiu and contributes diversified functional microbes for saccharifying grains and converting sugars into ethanol and aroma components in Baijiu products. Daqu is mainly classified into three types, namely low (LTD), medium (MTD) and high (HTD) temperature Daqu, according to the highest temperatures reached in their fermentation processes. In this study, we used the PacBio small-molecule real-time (SMRT) sequencing technology to determine the full-length 16 S rRNA gene sequences from the metagenomes of 296 samples of different types of Daqu collected from ten provinces in China, and revealed the bacterial diversity at the species level in the Daqu samples. We totally identified 310 bacteria species, including 78 highly abundant species (with a relative abundance &gt;0.1% each) which accounted for 91.90% of the reads from all the Daqu samples. We also recognized the differentially enriched bacterial species in different types of Daqu, and in the Daqu samples with the same type but from different provinces. Specifically, Lactobacillales, Enterobacterales and Bacillaceae were significantly enriched in the LTD, MTD and HTD groups, respectively. The potential co-existence and exclusion relationships among the bacteria species involved in all the Daqu samples and in the LTD, MTD and HTD samples from a specific region were also identified. These results provide a better understanding of the bacterial diversity in different types of Daqu at the species level.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0740002024001047/pdfft?md5=907bdac5c434fdb723a9e155da797dcd&pid=1-s2.0-S0740002024001047-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193591","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":"Influence of different stress factors during the elaboration of grape must's pied de cuve on the dynamics of yeast populations during alcoholic fermentation","authors":"Katherine Bedoya ,&nbsp;Luis Buetas ,&nbsp;Nicolas Rozès ,&nbsp;Albert Mas ,&nbsp;M. Carmen Portillo","doi":"10.1016/j.fm.2024.104571","DOIUrl":"10.1016/j.fm.2024.104571","url":null,"abstract":"<div><p>The <em>pied</em> <em>de</em> <em>cuve</em> (PdC) technique involves using a portion of grape must to undergo spontaneous fermentation, which is then used to inoculate a larger volume of must. This allows for promoting autochthonous yeasts present in the must, which can respect the typicality of the resulting wine. However, the real impact of this practice on the yeast population has not been properly evaluated. In this study, we examined the effects of sulphur dioxide (SO₂), temperature, ethanol supplementation, and time on the dynamics and selection of yeasts during spontaneous fermentation to be used as PdC. The experimentation was conducted in a synthetic medium and sterile must using a multi-species yeast consortium and in un-inoculated natural grape must. <em>Saccharomyces cerevisiae</em> dominated both the PdC and fermentations inoculated with commercial wine yeast, displaying similar population growth regardless of the tested conditions. However, using 40 mg/L of SO₂ and 1% (v/v) ethanol during spontaneous fermentation of Muscat of Alexandria must allowed the non-<em>Saccharomyces</em> to be dominant during the first stages, regardless of the temperature tested. These findings suggest that it is possible to apply the studied parameters to modulate the yeast population during spontaneous fermentation while confirming the effectiveness of the PdC methodology in controlling alcoholic fermentation.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0740002024001096/pdfft?md5=a4d887c1bd65189433f1425831f22dc2&pid=1-s2.0-S0740002024001096-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193802","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":"Occurrence, genetic characterization, and antibiotic susceptibility of Cronobacter spp. isolated from low water activity functional foods in Brazil","authors":"Carine da Fonseca Cechin ,&nbsp;Gabriela Guimarães Carvalho ,&nbsp;Dirce Yorika Kabuki","doi":"10.1016/j.fm.2024.104570","DOIUrl":"10.1016/j.fm.2024.104570","url":null,"abstract":"<div><p><em>Cronobacter</em> spp. are bacterial pathogens isolated from a wide variety of foods. This study aims at evaluating the occurrence of <em>Cronobacter</em> spp. in low water activity functional food samples, detect the presence of virulence genes, and determine the antibiotic susceptibility of strains. From 105 samples, 38 (36.2%) were contaminated with <em>Cronobacter</em> spp. The species identified by polymerase chain reaction (PCR) and sequencing analyses (<em>rpo</em>B and <em>fus</em>A genes, respectively) were <em>C. sakazakii</em> (60.3%), <em>C. dublinensis</em> (25.4%), <em>C. turincensis</em> (9.5%), and <em>C. malonaticus</em> (4.8%). Nineteen <em>fus</em>A alleles were identified, including four new alleles. The virulence genes were identified by PCR and all isolates were positive for <em>omp</em>X and <em>sod</em>A genes, 60.3% to <em>cpa</em> gene, and 58.7% to <em>hly</em> gene. Using the disk diffusion method, antibiotic susceptibility to twelve antibiotics was assessed twice, separated by a 19-month period. In the first test, the isolates showed diverse antibiotic susceptibility profiles, with nineteen isolates (30.2%) being multi-drug resistant (resistant to three or more antibiotic classes), in the second, the isolates were susceptible to all antibiotics. <em>Cronobacter</em> spp. in functional foods demonstrates the need for continued investigation of this pathogen in foods, and further research is needed to clarify the loss of resistance of <em>Cronobacter</em> strains.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193986","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":"Integrative metagenomics, volatilomics and chemometrics for deciphering the microbial structure and core metabolic network during Chinese rice wine (Huangjiu) fermentation in different regions","authors":"Yi Luo ,&nbsp;Chenhao Zhang ,&nbsp;Hui Liao ,&nbsp;Yunchuan Luo ,&nbsp;Xinlei Huang ,&nbsp;Zhenyu Wang ,&nbsp;Xia Xiaole","doi":"10.1016/j.fm.2024.104569","DOIUrl":"10.1016/j.fm.2024.104569","url":null,"abstract":"<div><p>Huangjiu is a spontaneously fermented alcoholic beverage, that undergoes intricate microbial compositional changes. This study aimed to unravel the flavor and quality formation mechanisms based on the microbial metabolism of Huangjiu. Here, metagenome techniques, chemometrics analysis, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC–MS) metabolomics combined with microbial metabolic network were employed to investigate the distinctions and relationship between the microbial profiles and the quality characteristics, flavor metabolites, functional metabolic patterns of Huangjiu across three regions. Significant variations (<em>P</em> &lt; 0.05) were observed in metabolic rate of physicochemical parameters and biogenic amine concentration among three regions. 8 aroma compounds (phenethyl acetate, phenylethyl alcohol, isobutyl alcohol, ethyl octanoate, ethyl acetate, ethyl hexanoate, isoamyl alcohol, and diethyl succinate) out of 448 volatile compounds were identified as the regional chemical markers. 25 dominant microbial genera were observed through metagenomic analysis, and 13 species were confirmed as microbial markers in three regions. A metabolic network analysis revealed that Saccharomycetales (<em>Saccharomyces</em>), Lactobacillales (<em>Lactobacillus</em>, <em>Weissella</em>, and <em>Leuconostoc</em>), and Eurotiales (<em>Aspergillus</em>) were the predominant populations responsible for substrate, flavor (mainly esters and phenylethyl alcohol) metabolism, Lactobacillales and Enterobacterales were closely linked with biogenic amine. These findings provide scientific evidence for regional microbial contributions to geographical characteristics of Huangjiu, and perspectives for optimizing microbial function to promote Huangjiu quality.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193801","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":"Serodiversity, antibiotic resistance, and virulence genes of Vibrio parahaemolyticus in oysters collected in coastal areas of northwestern Mexico between 2012 and 2020","authors":"Hector Flores-Villaseñor ,&nbsp;Jorge Velázquez-Román ,&nbsp;Nidia León-Sicairos ,&nbsp;Uriel A. Angulo-Zamudio ,&nbsp;Carolina Lira-Morales ,&nbsp;Jesús J. Martínez-García ,&nbsp;Erika Acosta-Smith ,&nbsp;Jorge Valdés-Flores ,&nbsp;Gabriela Tapia-Pastrana ,&nbsp;Adrian Canizalez-Román","doi":"10.1016/j.fm.2024.104567","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104567","url":null,"abstract":"<div><p>This study aimed to determine the prevalence of <em>V. parahaemolyticus</em> in oysters from the northwestern coast of Mexico and to identify the serotypes, virulence factors, and antibiotic resistance of the strains. Oyster samples were collected from 2012 to 2020 from the northwest coast of Mexico; biochemical and molecular methods were used to identify <em>V. parahaemolyticus</em> from oysters; antiserum reaction to determine <em>V. parahaemolyticus</em> serotypes, and PCR assays were performed to identify pathogenic (<em>tdh</em> and/or <em>trh</em>) or pandemic (<em>toxRS/new</em>, and/or <em>orf8</em>) strains and antibiotic resistance testing. A total of 441 oyster samples were collected and tested for <em>V. parahaemolyticus</em>. Forty-seven percent of oyster samples were positive for <em>V. parahaemolyticus</em>. Ten different O serogroups and 72 serovars were identified, predominantly serotype O1:KUT with 22.2% and OUT:KUT with 17.3%. Twenty new serotypes that had not been previously reported in our region were identified. We detected 4.3% of pathogenic clones but no pandemic strains. About 73.5% of strains were resistant to at least one antibiotic, mainly ampicillin and ciprofloxacin; 25% were multi-drug resistant. In conclusion, the pathogenic strains in oysters and antibiotic resistance are of public health concern, as the potential for outbreaks throughout northwestern Mexico is well established.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141242504","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":"Emergence of Salmonella Infantis carrying the pESI-like plasmid from eggs in egg grading and packing plants in Korea","authors":"Min Beom Kim,&nbsp;Young Ju Lee","doi":"10.1016/j.fm.2024.104568","DOIUrl":"10.1016/j.fm.2024.104568","url":null,"abstract":"<div><p>The plasmid of emerging <em>S</em>. Infantis (pESI) or pESI-like plasmid in <em>Salmonella enterica</em> Infantis are consistently reported in poultry and humans worldwide. However, there has been limited research on these plasmids of <em>S</em>. Infantis isolated from eggs. Therefore, this study aimed to analyze the prevalence and characteristics of <em>S</em>. Infantis carrying the pESI-like plasmid from eggs in egg grading and packing plants. In this study, the pESI-like plasmid was only detected in 18 (78.3%) of 23 <em>S</em>. Infantis isolates, and it was absent in the other 9 <em>Salmonella</em> serovars. In particular, <em>S</em>. Infantis isolates carrying the pESI-like plasmid showed the significantly higher resistance to β-lactams, phenicols, cephams, aminoglycosides, quinolones, sulfonamides, and tetracyclines than <em>Salmonella</em> isolates without the pESI-like plasmid (<em>p</em> &lt; 0.05). Moreover, all <em>S</em>. Infantis isolates carrying the pESI-like plasmid were identified as extended-spectrum β-lactamase (ESBL) producer, harboring the <em>bla</em>_CTX-M-65 and <em>bla</em>_TEM-1 genes, and carried non-β-lactamase resistance genes (<em>ant(3′′)-Ia</em>, <em>aph(4)-Ia</em>, <em>aac(3)-IVa</em>, <em>aph(3′)-Ic</em>, <em>sul1</em>, <em>tetA</em>, <em>dfrA14</em>, and <em>floR</em>) against five antimicrobial classes. However, all isolates without the pESI-like plasmid only carried the <em>bla</em>_TEM-1 gene among the β-lactamase genes, and either had no non-β-lactamase resistance genes or harbored non-β-lactamase resistance genes against one or two antimicrobial classes. Furthermore, all <em>S</em>. Infantis isolates carrying the pESI-like plasmid carried class 1 and 2 integrons and the <em>aadA1</em> gene cassette, but none of the other isolates without the pESI-like plasmid harbored integrons. In particular, D87Y substitution in the <em>gyrA</em> gene and IncP replicon type were observed in all the <em>S</em>. Infantis isolates carrying the pESI-like plasmid but not in the <em>S</em>. Infantis isolates without the pESI-like plasmid. The distribution of pulsotypes between pESI-positive and pESI-negative <em>S</em>. Infantis isolates was clearly distinguished, but all <em>S</em>. Infantis isolates were classified as sequence type 32, regardless of whether they carried the pESI-like plasmid. This study is the first to report the characteristics of <em>S</em>. Infantis carrying the pESI-like plasmid isolated from eggs and can provide valuable information for formulating strategies to control the spread of <em>Salmonella</em> in the egg industry worldwide.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193592","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":"Changes of microbial communities and metabolites in the fermentation of persimmon vinegar by bioaugmentation fermentation","authors":"Luyao Zhang ,&nbsp;Mengyang Wang ,&nbsp;Hairu Song ,&nbsp;Weina Liang ,&nbsp;Xiaotong Wang ,&nbsp;Jianrui Sun ,&nbsp;Dahong Wang","doi":"10.1016/j.fm.2024.104565","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104565","url":null,"abstract":"<div><p>To evaluate the effects of bioaugmentation fermentation inoculated with one ester-producing strain (<em>Wickerhamomyces anomalus</em> ZX-1) and two strains of lactic acid bacteria (<em>Lactobacillus plantarum</em> CGMCC 24035 and <em>Lactobacillus acidophilus</em> R2) for improving the flavor of persimmon vinegar, microbial community, flavor compounds and metabolites were analyzed. The results of microbial diversity analysis showed that bioaugmentation fermentation significantly increased the abundance of <em>Lactobacillus</em>, <em>Saccharomyces</em>, <em>Pichia</em> and <em>Wickerhamomyces</em>, while the abundance <em>of Acetobacter</em>, <em>Apiotrichum</em>, <em>Delftia</em>, <em>Komagataeibacter</em>, <em>Kregervanrija</em> and <em>Aspergillus</em> significantly decreased. After bioaugmentation fermentation, the taste was softer, and the sensory irritancy of acetic acid was significantly reduced. The analysis of HS-SPME-GC-MS and untargeted metabolomics based on LC-MS/MS showed that the contents of citric acid, lactic acid, malic acid, ethyl lactate, methyl acetate, isocitrate, acetoin and 2,3-butanediol were significantly increased. By multivariate analysis, 33 differential metabolites were screened out to construct the correlation between the differential metabolites and microorganisms. Pearson correlation analysis showed that methyl acetate, ethyl lactate, betaine, aconitic acid, acetoin, 2,3-butanediol and isocitrate positively associated with <em>Wickerhamomyces</em> and <em>Lactobacillus</em>. The results confirmed that the quality of persimmon vinegar was improved by bioaugmentation fermentation.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141083653","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":"Reliable and specific detection of Acanthamoeba spp. In dishcloths using quantitative real-time PCR assay","authors":"M. Reyes-Batlle ,&nbsp;E. Córdoba-Lanús ,&nbsp;A. Domínguez-de-Barros ,&nbsp;I. Sifaoui ,&nbsp;R.L. Rodríguez-Expósito ,&nbsp;S. Mantesa-Rodríguez ,&nbsp;J.E. Piñero ,&nbsp;J. Lorenzo-Morales","doi":"10.1016/j.fm.2024.104562","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104562","url":null,"abstract":"<div><p><em>Acanthamoeba</em> spp., are ubiquitous protist which belongs to Free-Living Amoeba (FLA) group, is considered as causal agent of side-threatening keratitis or fatal encephalitis among other human infections. Besides, this parasite has been reported as host for other microorganisms important to human health such as <em>Campylobacter</em> spp. or <em>Vibrio</em> spp. among others. This role of <em>Acanthamoeba</em> as pathogen and environmental phagocyte has increased the reports confirming its presence in human related environments, acting as a water quality indicator. Considering the tide relationship between water and kitchen environments, and the high prevalence of <em>Acanthamoeba</em> in water sources, the present study aims to establish a quick and accurate protocol based on DNA extraction and a real time qPCR assay to detect <em>Acanthamoeba</em> spp. in dishcloths. The procedure has been validated by processing 17 used dishcloths. Our findings demonstrated the high sensitivity of the qPCR assay used which was capable of detecting up to one <em>Acanthamoeba</em> from an <em>in vitro</em> contaminated dishcloth. The protocol accurately detected 64.7% of positive samples for <em>Acanthamoeba</em> spp, (in 4 samples DNA concentrations corresponded to 1-10² amoebae). Our findings demonstrate the importance of FLA surveillance by efficient and sensitive methods since one amoeba is capable of colonizing human related food environments such as kitchens sinks and could be a potential source of infection.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S074000202400100X/pdfft?md5=e00d743e6d7e7806dfcc7243917c8b36&pid=1-s2.0-S074000202400100X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141072690","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":"Comparative physiological and transcriptomic analysis of sono-biochemical control over post-acidification of Lactobacillus delbrueckii subsp. bulgaricus","authors":"Xiaohui Zhang ,&nbsp;Yuanrong Zheng ,&nbsp;Changyu Zhou ,&nbsp;Jinxuan Cao ,&nbsp;Daodong Pan ,&nbsp;Zhendong Cai ,&nbsp;Zhen Wu ,&nbsp;Qiang Xia","doi":"10.1016/j.fm.2024.104563","DOIUrl":"https://doi.org/10.1016/j.fm.2024.104563","url":null,"abstract":"<div><p>Thermosonication (UT) prestress treatments combining with varied fermentation patterns has been revealed as an effective method to regulate post-acidification as exerted by <em>Lactobacillus delbrueckii</em> subsp. <em>bulgaricus</em> (<em>L. delbrueckii</em>), but sono-biochemical controlling mechanisms remain elusive. This study employed physiological and transcriptomic analysis to explore the response mechanism of <em>L. delbrueckii</em> to UT-induced microstress (600 W, 33 kHz, 10 min). UT stress-induced inhibition of acidification of <em>L. delbrueckii</em> during (post)-fermentation was first confirmed, relying on the UT process parameters such as stress exposure duration and UT power. The significantly enhanced membrane permeability in cells treated by 600 W for 10 min than the microbes stressed by 420 W for 20 min suggested the higher dependence of UT-derived stresses on the treatment durations, relative to the ultrasonic powers. In addition, ultrasonication treatment-induced changes in cell membrane integrity enhanced and/or disrupted permeability of <em>L. delbrueckii</em>, resulting in an imbalance in intracellular conditions associated with corresponding alterations in metabolic behaviors and fermentation efficiencies. UT-prestressed inoculum exhibited a 21.46% decrease in the membrane potential during the lag phase compared to untreated samples, with an intracellular pH of 5.68 ± 0.12, attributed to the lower activities of H⁺-ATPase and lactate dehydrogenase due to UT stress pretreatments. Comparative transcriptomic analysis revealed that UT prestress influenced the genes related to glycolysis, pyruvate metabolism, fatty acid synthesis, and ABC transport. The genes encoding 3-oxoacyl-[acyl-carrier-protein] reductases I, II, and III, CoA carboxylase, lactate dehydrogenase, pyruvate oxidase, glucose-6-phosphate isomerase, and glycerol-3-phosphate dehydrogenase were downregulated, thus identifying the relevance of the UT microstresses-downregulated absorption and utilization of carbohydrates with the attenuated fatty acid production and energy metabolisms. These findings could contribute to provide a better understanding of the inactivated effects on the post-acidification of <em>L. delbrueckii</em> by ultrasonic pretreatments, thus providing theoretical basis for the targeted optimization of acidification inhibition efficiencies for yogurt products during chilled preservation processes.</p></div>","PeriodicalId":12399,"journal":{"name":"Food microbiology","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097841","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}