Aureobasidium pullulans volatile organic compounds as alternative postharvest method to control brown rot of stone fruits.
Abstract Volatile compounds produced by L1 and L8 strains were assayed against mycelia and conidia growth of Monilinia laxa, M. fructicola, M. polystroma, and M. fructigena of stone fruits. Results showed that volatile metabolites inhibited significantly pathogens growth, in particular M. fructigena mycelium growth (70% by L1 and 50% by L8) and M. fructicola conidia germination (85% by L1 and 70% by L8) compared to the control. Moreover, the antagonistic activity was enhanced by the addition of asparagine (120 mg L-1) in the culture media composition. Synthetic pure compounds were tested in vitro on path...
Source: Food Microbiology - January 19, 2020 Category: Food Science Authors: Di Francesco A, Di Foggia M, Baraldi E Tags: Food Microbiol Source Type: research

Evaluation of the U.S. Food and Drug Administration validated molecular method for detection of Cyclospora cayetanensis oocysts on fresh and frozen berries.
In conclusion, the FDA BAM Chapter 19B method for the detection of Cyclospora was robust, consistent, and showed high sensitivity in all types of berries analyzed. Evaluation of the FDA detection method in berries will provide reliable laboratory support for surveillance programs and for outbreak investigations. PMID: 31948637 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - January 19, 2020 Category: Food Science Authors: Assurian A, Murphy H, Ewing L, Cinar HN, da Silva A, Almeria S Tags: Food Microbiol Source Type: research

Role of DNA repair in Bacillus subtilis spore resistance to high energy and low energy electron beam treatments.
s A Abstract Bacillus subtilis spore inactivation mechanisms under low energy electron beam (LEEB) and high energy electron beam (HEEB) treatment were investigated using seven mutants lacking specific DNA repair mechanisms. The results showed that most of the DNA repair-deficient mutants, including ΔrecA, ΔKu ΔligD, Δexo Δnfo, ΔuvrAB and ΔsbcDC, had reduced resistances towards electron beam (EB) treatments at all investigated energy levels (80 keV, 200 keV and 10 MeV) compared to their wild type. This result suggested DNA damage was induced during EB treatments. The ...
Source: Food Microbiology - January 19, 2020 Category: Food Science Authors: Zhang Y, Huber N, Moeller R, Stülke J, Dubovcova B, Akepsimaidis G, Meneses N, Drissner D, Mathys A Tags: Food Microbiol Source Type: research

The impact of dry ageing vacuum-packed pork on the viability of Toxoplasma gondii tissue cysts.
Abstract The present study evaluated the viability of Toxoplasma gondii tissue cysts in dry-aged pork loins (m. longissimus) after 14, 21 and 28 days under controlled temperature (0 °C ± 1 °C). The pigs (n = 9) were orally inoculated with 3,000 T. gondii oocysts. The right loin of each pig was aged for a predetermined period, and the left loin was kept unprocessed as a control. Two experiments were performed. In Experiment 1, the loins of three pigs were aged for 14 days and then bioassayed in both cats and mice. In Experiment 2, the loins of six pigs were bioassayed only in mice, and th...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Alves BF, Gennari SM, Oliveira S, Soares HS, Conte-Junior CA, Dubey JP, Amaku M, Jesus Pena HF Tags: Food Microbiol Source Type: research

The dynamics of volatile compounds and their correlation with the microbial succession during the traditional solid-state fermentation of Gutian Hong Qu glutinous rice wine.
Abstract Gutian Hong Qu glutinous rice wine (GHQW) is a representative alcoholic beverage in China. During its traditional brewing process, multiple strains are involved. However, the roles of these microorganisms, particularly their contributions to aroma formation, are poorly understood. Therefore, in this study, the dynamics of volatile components and microbial succession during the traditional fermentation process of GHQW were monitored, by using HS-SPME-GC/MS and high throughput 16 S rRNA and ITS sequencing techniques. Following a 32-day semi-open solid-state fermentation, massive changes in volatile profil...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Liu Z, Wang Z, Sun J, Ni L Tags: Food Microbiol Source Type: research

Structural enterocin gene profiles and mode of antilisterial activity in synthetic liquid media and skim milk of autochthonous Enterococcus spp. isolates from artisan Greek Graviera and Galotyri cheeses.
Abstract The presence of eight common structural enterocin genes, singly or in varying combinations, in the genome of 15 antagonistic Enterococcus spp. previously isolated from artisan Greek Graviera and Galotyri retail cheeses was tested and associated with the mode of enterocin (Ent+) antilisterial activity of each isolate in three liquid culture media. The isolates were assigned to nine distinct strain genotypes of E. faecium (4 strains), E. durans (2) and E. faecalis (3). All strains were non-hemolytic, except for a cyl-positive E. faecalis genotype isolated from Galotyri cheese, which was strongly listericida...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Vandera E, Parapouli M, Kakouri A, Koukkou AI, Hatziloukas E, Samelis J Tags: Food Microbiol Source Type: research

An overview of Yersinia enterocolitica and related species in samples of different origin from San Luis, Argentina.
This study is aimed at offering an overview of the prevalence of Yersinia enterocolitica and related species in San Luis, Argentina, from samples of diverse origin received in our laboratory between 1984 and 2014, and providing an analysis of the distribution of Yersinia isolates according to their isolation sources, highlighting bioserotypes and potential reservoirs and vehicles of transmission to humans. From a total of 4572 samples of human, animal, food and environmental origins analyzed by traditional culture methods and molecular techniques, 229 (5%) samples were Yersinia positive. The highest frequency of Yersinia i...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Lucero-Estrada C, Favier GI, Escudero ME Tags: Food Microbiol Source Type: research

Inactivation of Escherichia coli O157:H7 in apple cider by resveratrol and naringenin.
Abstract The study investigated the efficacy of two GRAS-status phytochemicals, mega-resveratrol (RV) and naringenin (NG) to inactivate Escherichia coli O157:H7 (EHEC) in apple cider. A five-strain mixture of EHEC (∼7 log CFU/ml) was inoculated into cider, followed by the addition of RV (8.7 mM and 13.0 mM) or NG (7.3 mM and 11.0 mM). The cider samples were stored at 4 °C for 14 days and EHEC was enumerated on days 0,1,5,7 and 14. The deleterious effects of RV and NG on EHEC cells were visualized by scanning electron microscopy (SEM), and RT-qPCR was done to determine the effect of phytochemicals...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Surendran Nair M, Ma F, Lau P, Upadhyaya I, Venkitanarayanan K Tags: Food Microbiol Source Type: research

Application of MALDI-TOF MS to species complex differentiation and strain typing of food related fungi: Case studies with Aspergillus section Flavi species and Penicillium roqueforti isolates.
, Mounier J Abstract Filamentous fungi are one of the main causes of food losses worldwide and their ability to produce mycotoxins represents a hazard for human health. Their correct and rapid identification is thus crucial to manage food safety. In recent years, MALDI-TOF emerged as a rapid and reliable tool for fungi identification and was applied to typing of bacteria and yeasts, but few studies focused on filamentous fungal species complex differentiation and typing. Therefore, the aim of this study was to evaluate the use of MALDI-TOF to identify species of the Aspergillus section Flavi, and to differentiate ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Quéro L, Courault P, Cellière B, Lorber S, Jany JL, Puel O, Girard V, Vasseur V, Nodet P, Mounier J Tags: Food Microbiol Source Type: research

Synergistic activities of gaseous oregano and thyme thymol essential oils against Listeria monocytogenes on surfaces of a laboratory medium and radish sprouts.
Abstract We investigated combinations of gaseous essential oils (EO gases) for their synergistic inhibitory activities against Listeria monocytogenes on a laboratory medium and radish sprouts. The minimum inhibitory concentrations and minimum lethal concentrations of oregano, thyme thymol, and cinnamon bark EO gases against L. monocytogenes were 0.0781 μL/mL on nutrient agar supplemented with glucose and bromocresol purple (NGBA). A checkerboard assay showed that combinations of oregano and thyme thymol EO gases and of oregano and cinnamon bark EO gases exert the strongest synergistic antilisterial activity (...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Cho Y, Kim H, Beuchat LR, Ryu JH Tags: Food Microbiol Source Type: research

Persistence of a mixed lactic acid bacterial starter culture during lysine fortification of sourdough breads by addition of pistachio powder.
Abstract Pistachio powder was added to flour or semolina to evaluate its contribution to increase the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species (Lactobacillus sanfranciscensis/Leuconostoc citreum/Weissella cibaria) lactic acid bacterial (LAB) starter culture. All sourdoughs were subjected to a long-time fermentation (21 h) and showed levels of LAB around 109 CFU/g, indicating the suitability of pistachio powder for lactic fermentation. Yeasts were also detected, in particular in semolina trials. MiSeq Illumina technology was applied to invest...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Gaglio R, Alfonzo A, Barbera M, Franciosi E, Francesca N, Moschetti G, Settanni L Tags: Food Microbiol Source Type: research

A long-amplicon quantitative PCR assay with propidium monoazide to enumerate viable Listeria monocytogenes after heat and desiccation treatments.
The objective of this study was to develop a qPCR method for specific enumeration of viable Listeria monocytogenes in food processing facilities and heat treated products. Primers specific for L. monocytogenes were designed to amplify a short (199 bp) or long (1561 bp) fragment of the listeriolysin (hly) gene. The short- and long-amplicon qPCR methods with and without propidium monoazide (PMA) treatment of the cells were tested for their ability to discriminate between viable (no heat) and heat-killed cells (90 °C, 10 min). The PMA-qPCR methods were subsequently used to assess the survival of L. monocytogenes durin...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Kragh ML, Thykier M, Truelstrup Hansen L Tags: Food Microbiol Source Type: research

The serine proteases CspA and CspC are essential for germination of spores of Clostridium perfringens SM101 through activating SleC and cortex hydrolysis.
In this study, the expression of cspA and cspC, as well as the germination and colony formation by spores of cspAC and cspC mutants of strain SM101, were assessed. We demonstrated that 1) the cspA and cspC genes were expressed as a bicistronic operon only during sporulation in the mother cell compartment of SM101; 2) both cspAC and cspC mutant spores were unable to germinate significantly with either KCl, l-glutamine, brain heart infusion (BHI) broth, or a 1:1 chelate of Ca2+ and dipicolinic acid (DPA); 3) consistent with germination results, both cspAC and cspC mutant spores were defective in normal DPA release; 4) the co...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Talukdar PK, Sarker MR Tags: Food Microbiol Source Type: research

Transcriptional analysis of galactomannooligosaccharides utilization by Lactobacillus plantarum WCFS1.
Abstract Plant derived galactomannooligosaccharides (GMOS) are an emerging class of prebiotics, but no information is available on their utilization in lactobacilli at the molecular level. The current study aimed at identifying the genetic loci involved in the transport and catabolism of locust bean gum derived GMOS in Lactobacillus plantarum WCFS1. Substrate depletion study showed that L. plantarum WCFS1 can metabolize only short chain GMOS (degree of polymerization; DP ≤ 3). Global transcriptome microarray profiling of L. plantarum WCFS1 revealed differential expression when GMOS or control sugars (glucos...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Panwar D, Kapoor M Tags: Food Microbiol Source Type: research

Identification of the bacteria and their metabolic activities associated with the microbial spoilage of custard cream desserts.
This study explored the bacterial diversity of 64 spoiled custard cream desserts manufactured by 2 French companies. B. cereus group bacteria, coagulase negative Staphylococcus, Enterococcus and Leuconostoc spp. were isolated from spoiled products. Thirty-one bacterial isolates representative of the main spoilage species were tested for their spoilage abilities. Significant growth and pH decrease were observed regardless of species. While off-odours were detected with B. cereus group and staphylococci, yoghurt odours were detected with Enterococcus spp. and Leuconostoc spp. B. cereus group bacteria produced various esters ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Techer C, Jan S, Thierry A, Maillard MB, Grosset N, Galet O, Breton V, Gautier M, Baron F Tags: Food Microbiol Source Type: research

Methyl anthranilate: A novel quorum sensing inhibitor and anti-biofilm agent against Aeromonas sobria.
Abstract Quorum sensing (QS), bacterial cell-to-cell communication, is a gene regulatory mechanism that regulates virulence potential and biofilm formation in many pathogens. Aeromonas sobria, a common aquaculture pathogen, was isolated and identified by our laboratory from the deteriorated turbot, and its potential for virulence factors and biofilm production was regulated by QS system. In view of the interference with QS system, this study was aimed to investigate the effect of methyl anthranilate at sub-Minimum Inhibitory Concentrations (sub-MICs) on QS-regulated phenotypes in A. sobria. The results suggested t...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Li T, Sun X, Chen H, He B, Mei Y, Wang D, Li J Tags: Food Microbiol Source Type: research

High-throughput sequencing approach to characterize dynamic changes of the fungal and bacterial communities during the production of sufu, a traditional Chinese fermented soybean food.
In this study, sufu samples were periodically collected during the whole fermentation to investigate the dynamic changes of fungal and bacterial communities using high-throughput sequencing technology. The overall process can be divided into pre- and post-fermentation. During post-fermentation, the pH value showed a gradual decrease over time while the amino nitrogen content increased. Trichosporon, Actinomucor and Cryptococcus were the main genera in pre-fermentation while Monascus and Aspergillus were dominant in post-fermentation. This huge shift in fungal composition was caused by process procedure of pouring dressing ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Xu D, Wang P, Zhang X, Zhang J, Sun Y, Gao L, Wang W Tags: Food Microbiol Source Type: research

Shiga toxin-producing Escherichia coli isolates from red deer (Cervus elaphus), roe deer (Capreolus capreolus) and fallow deer (Dama dama) in Poland.
We examined 252 rectal swabs obtained from 134 roe deer (Capreolus capreolus), 97 red deer (Cervus elaphus) and 21 fallow deer (Dama dama) in north-eastern Poland. The samples were enriched in modified buffered peptone water. Polymerase chain reaction (PCR) assays were conducted to determine the virulence profile of stx1, stx2 and eae or aggR genes, to identify the subtypes of stx1 and stx2 genes, and to perform O and H serotyping. E. coli O157:H7 isolates were detected in the rectal swabs collected from 1/134 roe deer (0.75%) and 4/97 red deer (4.1%), and they were not detected in fallow deer (Dama dama). The remaining E....
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Szczerba-Turek A, Siemionek J, Socha P, Bancerz-Kisiel A, Platt-Samoraj A, Lipczynska-Ilczuk K, Szweda W Tags: Food Microbiol Source Type: research

Antimicrobial activity of gaseous chlorine dioxide against Aspergillus flavus on green coffee beans.
Abstract The aim of this study was to use chlorine dioxide (ClO2) gas to inactivate Aspergillus flavus on green coffee beans. Green coffee beans inoculated with A. flavus were exposed to ClO2 gas generated from 0.75, 1, 1.25, or 1.5 mL of ClO2 solution in a sealed container at 25 or 50 °C (100% relative humidity [RH]) for up to 10 h. Numbers of A. flavus on beans treated at 25 °C decreased by 1.1-2.2 log cfu/bean within 1 h of exposure to ClO2 and decreased to below the detection limit (≤1.0 log cfu/bean) at all ClO2 concentrations after 10 h. At 50 °C, the microbial population reached...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Lee H, Ryu JH, Kim H Tags: Food Microbiol Source Type: research

Inactivation of Salmonella spp. in tahini using plant essential oil extracts.
The objectives of the current study were to investigate: i) the effectiveness of 10 plant essential oil extracts on the viability of Salmonella spp. using disc diffusion ii) the antimicrobial activity of the most effective oils against Salmonella spp. in commercial or 10% w/v hydrated tahini (tahini-based product model) stored at 37, 25 and 10 °C for 28 d and iii) the effect of the addition of essential oil extracts on the sensory acceptability of tahini and hydrated tahini. Among the tested essential oils, thyme (TO) and cinnamon oil (CO) showed the highest antimicrobial activity against tested Salmonella spp. at ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Al-Nabulsi AA, Osaili TM, Olaimat AN, Almasri WE, Ayyash M, Al-Holy MA, Jaradat ZW, Obaid RS, Holley RA Tags: Food Microbiol Source Type: research

Changes of the bacterial community diversity on chicken carcasses through an Australian poultry processing line.
In this study, 10 chicken carcasses were randomly sampled from before and after scalding, before and after immersion chilling, and after air chilling each through a modern commercial processing line, along with the contents of 10 caeca. The sampled processing line effectively reduced the bacterial counts by > 4.6 Log10 CFU/ml for each of Total Viable Counts, Escherichia coli and Campylobacter. However, the metagenomics results suggested that Lactobacillus, Staphylococcus and unclassified Lachnospiraceae persisted at all sampling stages. Pseudomonas, Paeniglutamicibacter, Chryseobacterium and Pseudarthrobacter comp...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Chen SH, Fegan N, Kocharunchitt C, Bowman JP, Duffy LL Tags: Food Microbiol Source Type: research

Antibacterial effect and mechanisms of action of 460-470  nm light-emitting diode against Listeria monocytogenes and Pseudomonas fluorescens on the surface of packaged sliced cheese.
Antibacterial effect and mechanisms of action of 460-470 nm light-emitting diode against Listeria monocytogenes and Pseudomonas fluorescens on the surface of packaged sliced cheese. Food Microbiol. 2020 Apr;86:103314 Authors: Hyun JE, Lee SY Abstract The aim of this study was to investigate the antibacterial effect of 460-470 nm light-emitting diode (LED460-470nm) illumination against pathogens and spoilage bacteria on the surface of agar media and packaged sliced cheese. LED460-470nm illumination highly inhibited the growth of Listeria monocytogenes and Pseudomonas fluorescens on agar media cover...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Hyun JE, Lee SY Tags: Food Microbiol Source Type: research

The antimicrobial activity of coenzyme Q0 against planktonic and biofilm forms of Cronobacter sakazakii.
In this study, the antimicrobial activity and possible antimicrobial mechanism of CoQ0 against C. sakazakii were investigated. Moreover, the inactivation effect of CoQ0 on C. sakazakii in biofilms was also evaluated. The minimum inhibitory concentration (MIC) of CoQ0 against C. sakazakii strains ranged from 0.1 to 0.2 mg/mL. Treatment caused cell membrane dysfunction, as evidenced by cell membrane hyperpolarization, decreased intracellular ATP concentration and cell membrane integrity, and changes in cellular morphology. CoQ0 combined with mild heat treatment (45, 50, or 55 °C) decreased the number of viable non-de...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Guo D, Wang S, Li J, Bai F, Yang Y, Xu Y, Liang S, Xia X, Wang X, Shi C Tags: Food Microbiol Source Type: research

Metagenomic analysis reveals the impact of JIUYAO microbial diversity on fermentation and the volatile profile of Shaoxing-jiu.
This study focused on the microbial communities found in JIUYAO, the fermentation starter traditionally used in Shaoxing-jiu, and elucidated their relationship with the fermentation activities and volatile compounds involved in winemaking. The microbial communities found in all JIUYAO samples tested were dominated by Pediococcus and Weissella bacteria and Saccharomycopsis and Rhizopus fungi. Saccharifying power showed significant positive correlations with the presence of Pedioccoccus, Saccharomycopsis, and Rhizopus, whereas acid production capacity was strongly associated with Pedioccoccus, Weissella, and Rhizopus. Alcoho...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Chen C, Liu Y, Tian H, Ai L, Yu H Tags: Food Microbiol Source Type: research

Unique response characteristics in persistent strains of Listeria monocytogenes exposed to low pH.
This study aimed to elucidate the response of persistent strains of L. monocytogenes to low pH and H2O2 exposure. Almost all of the persistent strains examined were highly susceptible to low pH, whereas H2O2 susceptibility was comparable to that of control strains. Two persistent strains isolated from the same sample, however, exhibited lower susceptibility to low pH. These findings suggest an acid-susceptible phenotype predominates in the habitat, indicating that environmental conditions contribute to the establishment of persistence. Representative strains exhibiting acid-susceptible and less acid-susceptible phenotypes ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Ochiai Y, Yoshikawa Y, Mochizuki M, Takano T, Ueda F Tags: Food Microbiol Source Type: research

Effects of phytic acid and lysozyme on microbial composition and quality of grass carp (Ctenopharyngodon idellus) fillets stored at 4  °C.
This study investigated the effect of phytic acid and lysozyme on the microbial composition and quality of grass carp (Ctenopharyngodon idellus) fillets stored at 4 °C. The control, 0.5 mg/mL lysozyme-treated fillets (T1), 0.5 mg/mL phytic acid-treated fillets (T2) and 0.25 mg/mL lysozyme + 0.25 mg/mL phytic acid-treated fillets (T3) were evaluated based on sensory assessment, biogenic amines, ATP-related compounds, total volatile basic nitrogen (TVB-N), and total viable counts (TVC). Changes in microbial composition were analyzed using high-throughput sequencing. Results showed that phytic acid and lyso...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Sun X, Hong H, Jia S, Liu Y, Luo Y Tags: Food Microbiol Source Type: research

The effect of salt concentrations on the fermentation of doenjang, a traditional Korean fermented soybean paste.
This study provides a deeper understanding of doenjang fermentation and insight into the development of low salt doenjang. PMID: 31703874 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Chun BH, Kim KH, Jeong SE, Jeon CO Tags: Food Microbiol Source Type: research

Genomic and metabolic features of Lactobacillus sakei as revealed by its pan-genome and the metatranscriptome of kimchi fermentation.
Abstract The genomic and metabolic features of Lactobacillus sakei were investigated using its pan-genome and by analyzing the metatranscriptome of kimchi fermentation. In the genome-based relatedness analysis, the strains were divided into the Lb. sakei ssp. sakei and Lb. sakei ssp. carnosus lineage groups. Genomic and metabolic pathway analysis revealed that all Lb. sakei strains have the capability of producing d/l-lactate, ethanol, acetate, CO2, formate, l-malate, diacetyl, acetoin, and 2,3-butanediol from d-glucose, d-fructose, d-galactose, sucrose, d-lactose, l-arabinose, cellobiose, d-mannose, d-gluconate, ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Kim KH, Chun BH, Baek JH, Roh SW, Lee SH, Jeon CO Tags: Food Microbiol Source Type: research

Modelling the combined effect of chlorine, benzyl isothiocyanate, exposure time and cut size on the reduction of Salmonella in fresh-cut lettuce during washing process.
C, Pérez-Rodríguez F Abstract This work aimed to study the effect of the combination of Sodium hypochlorite, the most used disinfectant by the vegetable industry, with a natural antimicrobial, benzyl-isothiocyanate (BITC), considering cutting surface and contact time, on the reduction of Salmonella in fresh-cut produce in washing operations under typical industrial conditions. Overall, the combinations of disinfectant and process parameters resulted in a mean reduction of Salmonella of 2.5 log CFU/g. According to statistical analysis, free chlorine and BITC concentrations, contact time and cut size ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Cuggino SG, Bascón-Villegas I, Rincón F, Pérez MA, Posada-Izquierdo G, Marugán J, Pablos Carro C, Pérez-Rodríguez F Tags: Food Microbiol Source Type: research

Inhibition of biofilm formation and exopolysaccharide synthesis of Enterococcus faecalis by phenyllactic acid.
This study aimed to evaluate the inhibitory activity of phenyllactic acid (PLA) against the biofilm formation of Enterococcus faecalis and to explore its potential molecular mechanism. The MIC value of PLA that inhibited the growth of E. faecalis R612-Z1 in BHI broth was 5 mg/mL. PLAs at subinhibitory concentrations of 1.25 and 2.50 mg/mL were found to inhibit biofilm formation by a crystal violet staining assay. The cell swimming and swarming motilities of E. faecalis were reduced in the presence of PLA. An apparent decrease in the thickness of PLA-treated biofilms was observed through confocal laser scanning microsco...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Liu F, Sun Z, Wang F, Liu Y, Zhu Y, Du L, Wang D, Xu W Tags: Food Microbiol Source Type: research

Isolation of virulent phages infecting dominant mesophilic aerobic bacteria in cucumber pickle fermentation.
This study suggests that PhageMIX combined with lactic acid bacterial strains can be used as an ecological starter for controlling the dominant MABs P. mendocina and E. cloacae and for reducing nitrate production during the early stage of pickle fermentation. PMID: 31703878 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Zheng XF, Yang ZQ, Zhang H, Jin WX, Xu CW, Gao L, Rao SQ, Jiao XA Tags: Food Microbiol Source Type: research

Survival of Lactobacillus acidophilus LA-5 and Escherichia coli O157:H7 in Minas Frescal cheese made with oregano and rosemary essential oils.
, Magnani M Abstract The effects of the incorporation of the essential oils from Origanum vulgare L. (OVEO; 0.07 μL/g) and Rosmarinus officinalis L. (ROEO; 2.65 μL/g) in combination in Minas Frescal cheese on the counts of the probiotic Lactobacillus acidophilus LA-5 and Escherichia coli O157:H7 were evaluated during refrigerated storage (7 ± 0.5 °C). The terpenes of OVEO and ROEO, survival of the probiotic strain during in vitro digestion, as well as the physicochemical and sensory aspects were also monitored in Minas Frescal cheese. All terpenes decreased in cheese when the storage tim...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Diniz-Silva HT, Brandão LR, de Sousa Galvão M, Madruga MS, Maciel JF, Leite de Souza E, Magnani M Tags: Food Microbiol Source Type: research

Production of melatonin and other tryptophan derivatives by Oenococcus oeni under winery and laboratory scale.
Abstract Malolactic fermentation (MLF) in Valtellina Superiore DOCG red wine was monitored in 4 cellars and the final products were analysed to determine the content of melatonin (MEL) and other tryptophan (TRP) derivatives, including tryptophan ethyl ester (TEE) and MEL isomers (MISs), and to isolate predominant O. oeni strains. MEL and TEE significantly increased in wines after MLF from two cellars out of four. Six strains were isolated during the MLF of red wines and under laboratory scale, in rich and synthetic wine cultural media, together with other four O. oeni strains able to trigger the MLF. Results showe...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Fracassetti D, Francesco Lo Faro AF, Moiola S, Orioli M, Tirelli A, Iriti M, Vigentini I, Foschino R Tags: Food Microbiol Source Type: research

Non-thermal approach to Listeria monocytogenes inactivation in milk: The combined effect of high pressure, pediocin PA-1 and bacteriophage P100.
The objective of the present work was to evaluate the effect of a process which combines mild high hydrostatic pressure - HHP (200 and 300 MPa, 5 min, 10 °C), phage Listex™ P100 and the bacteriocin pediocin PA-1 as a new non-thermal process for destruction of Listeria monocytogenes (104 CFU mL-1 or 107 CFU mL-1) in milk. For inoculum levels of 104 CFU mL-1, HHP combined with phage P100 eliminated L. monocytogenes immediately after pressurization. When L. monocytogenes was inoculated at levels of 107 CFU mL-1, a synergistic effect between phage P100, pediocin PA-1 and HHP (300 MPa) on the i...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Komora N, Maciel C, Pinto CA, Ferreira V, Brandão TRS, Saraiva JMA, Castro SM, Teixeira P Tags: Food Microbiol Source Type: research

Plant variety and soil type influence Escherichia coli O104:H4 strain C227/11 ϕcu adherence to and internalization into the roots of lettuce plants.
Plant variety and soil type influence Escherichia coli O104:H4 strain C227/11ϕcu adherence to and internalization into the roots of lettuce plants. Food Microbiol. 2020 Apr;86:103316 Authors: Eissenberger K, Drissner D, Walsh F, Weiss A, Schmidt H Abstract Human disease outbreaks caused by pathogenic Escherichia coli are increasingly associated with the consumption of contaminated fresh produce. Internalization of enteroaggregative/enterohemorrhagic E. coli (EAEC/EHEC) strains into plant tissues may present a serious threat to public health. In the current study, the ability of the fluorescing Shiga ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Eissenberger K, Drissner D, Walsh F, Weiss A, Schmidt H Tags: Food Microbiol Source Type: research

Persistence and reservoirs of Saccharomyces cerevisiae biodiversity in different vineyard niches.
do LA PMID: 31703883 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: González ML, Sturm ME, Lerena MC, Rojo MC, Chimeno SV, Combina M, Mercado LA Tags: Food Microbiol Source Type: research

Dynamics of physicochemical factors and microbial communities during ripening fermentation of Pixian Doubanjiang, a typical condiment in Chinese cuisine.
In this study, the physicochemical factors including pH value, titratable acidity, moisture, organic acids, free amino acids and volatile components etc., were identified; the compositions of microbial communities and representative microbiota were investigated; the correlations between physicochemical factors and representative microbial taxa were analyzed, at different ripening stages. The results indicated that the organic acids were all relatively stable starting from the 12th month; most of the free amino acids (17/20) reached the peak concentrations at the 6th month and 28 volatile components were considered as major...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Zhang L, Che Z, Xu W, Yue P, Li R, Li Y, Pei X, Zeng P Tags: Food Microbiol Source Type: research

Inhibition of Escherichia coli O157:H7 and Salmonella enterica virulence factors by benzyl isothiocyanate.
Abstract Escherichia coli O157:H7 and Salmonella enterica are foodborne pathogens with major public health concern in the U.S. These pathogens utilize several virulence factors to initiate infections in humans. The antimicrobial effect of seven glucosinolate hydrolysis compounds against Salmonella and E. coli O157:H7 was investigated by the disc diffusion assay. Among the tested compounds, benzyl isothiocyanate (BIT), which exerted the highest antimicrobial activity, was evaluated for its anti-virulence properties against these pathogens. The effect of BIT on motility of Salmonella and E. coli O157:H7 and Shiga to...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Patel J, Yin HB, Bauchan G, Mowery J Tags: Food Microbiol Source Type: research

Yeast and bacterial diversity, dynamics and fermentative kinetics during small-scale tequila spontaneous fermentation.
Iturriaga M Abstract The study of microbial communities associated with spontaneous fermentation of agave juice for tequila production is required to develop starter cultures that improve both yield and quality of the final product. Quantification by HPLC of primary metabolites produced during the fermentations was determined. A polyphasic approach using plate count, isolation and identification of microorganisms, denaturing gradient gel electrophoresis and next generation sequencing was carried out to describe the diversity and dynamics of yeasts and bacteria during small-scale spontaneous fermentations of agave ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Aldrete-Tapia JA, Escalante-Minakata P, Martínez-Peniche RA, Tamplin ML, Hernández-Iturriaga M Tags: Food Microbiol Source Type: research

Contribution of glutaminases to glutamine metabolism and acid resistance in Lactobacillus reuteri and other vertebrate host adapted lactobacilli.
This study aimed to investigate the distribution of glutaminase(s) in lactobacilli, and to evaluate their contribution in L. reuteri to amino acid metabolism and acid resistance. Phylogenetic analysis of the glutaminases gls1, gls2 and gls3 in the genus Lactobacillus demonstrated that glutaminase is exclusively present in host-adapted species of lactobacilli. The disruption gls1, gls2 and gls3 in L. reuteri 100-23 had only a limited effect on the conversion of glutamine to glutamate, GABA, or γ-glutamyl peptides in sourdough. The disruption of all glutaminases in L. reuteri 100-23Δgls1Δgls2Δgls3 but...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Li Q, Tao Q, Teixeira JS, Shu-Wei Su M, Gänzle MG Tags: Food Microbiol Source Type: research

Effect of drying on oxidation of membrane lipids and expression of genes encoded by the Shiga toxin prophage in Escherichia coli.
This study investigated the effect of drying on membrane lipid oxidation and stx expression in E. coli. Lipid peroxidation was probed with C11-BODIPY581/591; and stx expression was assayed by quantification of GFP in E. coli O104:H4 Δstx2a:gfp:ampr. Treatment of E. coli with H2O2 oxidized the probe; probe oxidation was also observed after drying and rehydration. Lipid oxidation and the lethality of drying were reduced when cells were dried with trehalose under anaerobic condition; in addition, viability and probe oxidation differed between E. coli AW1.7 and E. coli AW1.7Δcfa. Desiccation tolerance thus relates ...
Source: Food Microbiology - November 12, 2019 Category: Food Science Authors: Fang Y, McMullen LM, Gänzle MG Tags: Food Microbiol Source Type: research

Shell egg pasteurization using radio frequency in combination with hot air or hot water.
This study investigated the effectiveness of three thermal treatments; hot air (HA), hot water immersion (HWI), and hot water spraying (HWS); alone and in combination with radio frequency (RF) on the inactivation of Salmonella Typhimurium in shell eggs. In addition, the physical quality of the treated eggs and their functional capability to produce angel food cakes were determined. The results showed that HWI and HWS were significantly (P 
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Yang Y, Geveke DJ Tags: Food Microbiol Source Type: research

Metagenomic insights into the changes in microbial community and antimicrobial resistance genes associated with different salt content of red pepper (Capsicum annuum L.) sauce.
In this study, a combination of whole genome sequencing and amplicon analysis was used to investigate the changes in microbial community and antimicrobial resistance genes in response to different salt content during red pepper fermentation. While the family Enterobacteriaceae dominated in high-salt (15-25%) samples, Lactobacillaceae quickly became the dominant population in place of Enterobacteriaceae after 24 days in 10% salt samples. Compared to 0.05 antibiotic resistance genes (ARGs) per cell number on average in 10% salt sample, 16.6 ARGs were present in high-salt samples, wherein the bacterial hosts were major assign...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Li Z, Dong L, Zhao C, Zhu Y Tags: Food Microbiol Source Type: research

Why be serious about emetic Bacillus cereus: Cereulide production and industrial challenges.
z M Abstract Cereulide, a potent toxin produced by Bacillus cereus, is a small, highly heat- and acid-resistant depsipeptide toxin, which confronts food industry with several challenges. Due to the ubiquitous presence of B. cereus in the environment, this opportunistic pathogen can enter food production and processing at almost any stage. Although the bacteria itself might be removed during food processing, the cereulide toxin will most likely not be destroyed or inactivated by these processes. Because of the high toxicity of cereulide and the high incidence rates often observed in connection with foodborne outbre...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Rouzeau-Szynalski K, Stollewerk K, Messelhäusser U, Ehling-Schulz M Tags: Food Microbiol Source Type: research

A microbial challenge study for validating continuous radio-frequency assisted thermal processing pasteurization of egg white powder.
In this study, continuous RF processing was evaluated for pasteurization of EWP. EWP samples were inoculated with a 5-strain Salmonella cocktail or Enterococcus faecium NRRL B-2354 for the microbial challenge studies. To evaluate the inoculation method, stability and homogeneity tests were conducted for both Salmonella and E. faecium in EWP. Continuous RF heating of EWP was conducted in a 6-kW, 27.12 MHz pilot-scale parallel-plate RF heating system. RF-assisted thermal processing of EWP at 80 °C for 2 h provided>6.69 log reduction for Salmonella. E. faecium was found to be a suitable surrogate for Salmonella d...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Wei X, Lau SK, Reddy BS, Subbiah J Tags: Food Microbiol Source Type: research

Growth of Clostridium perfringens in cooked chicken during cooling: One-step dynamic inverse analysis, sensitivity analysis, and Markov Chain Monte Carlo simulation.
The objective of this study was to determine the kinetic parameters and apply Markov Chain Monte Carlo (MCMC) simulation to predict the growth of Clostridium perfringens from spores in cooked ground chicken meat during dynamic cooling. Inoculated samples were exposed to various cooling conditions to observe dynamic growth. A combination of 4 cooling profiles was used in one-step inverse analysis with the Baranyi model as the primary model and the cardinal parameters model as the secondary model. Six kinetic parameters of the Baranyi model and the cardinal parameters model, including Q0, Ymax, μopt, Tmin, Topt, and Tmax,...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Huang L, Li C Tags: Food Microbiol Source Type: research

Viral metagenomic analysis of the cheese surface: A comparative study of rapid procedures for extracting viral particles.
This study provides the basis of future investigations regarding the ecological importance of viruses in cheese microbial ecosystems. PMID: 31500705 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Dugat-Bony E, Lossouarn J, De Paepe M, Sarthou AS, Fedala Y, Petit MA, Chaillou S Tags: Food Microbiol Source Type: research

Ten years of molecular epidemiology surveillance of Listeria monocytogenes in Chile 2008-2017.
This study reports ten years of epidemiological surveillance ofL. monocytogenes in Chile. PMID: 31500706 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Paduro C, Montero DA, Chamorro N, Carreño LJ, Vidal M, Vidal R Tags: Food Microbiol Source Type: research

Nitrogen sources preferences of non-Saccharomyces yeasts to sustain growth and fermentation under winemaking conditions.
;n JM Abstract Wine-related non-Saccharomyces yeasts are becoming more widely used in oenological practice for their ability to confer wine a more complex satisfying aroma, but their metabolism remains unknown. Our study explored the nitrogen utilisation profile of three popular non-Saccharomyces species, Torulaspora delbrueckii, Metschnikowia pulcherrima and Metschnikowia fructicola. The nitrogen source preferences to support growth and fermentation as well as the uptake order of different nitrogen sources during wine fermentation were investigated. While T. delbrueckii and S. cerevisiae strains shared the same n...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Su Y, Seguinot P, Sanchez I, Ortiz-Julien A, Heras JM, Querol A, Camarasa C, Guillamón JM Tags: Food Microbiol Source Type: research

Sourdough bacterial dynamics revealed by metagenomic analysis in Brazil.
This study dealt with the influence of the temperature on the bacterial dynamics of two spontaneously fermented wheat sourdoughs, propagated at 21 ± 1 °C (SD1) and 30 ± 1 °C (SD2), during nine backslopping steps (BS1 to BS9). Proteobacteria was the only phylum found in flour. Escherichia hermannii was predominant, followed by Kosakonia cowanii, besides species belonging to the genera Pantoea and Pseudomonas. After one step of propagation, Clostridium and Bacillus cereus group became predominant. Lactobacillus curvatus was found at low relative abundance. For the second backslopping step, C...
Source: Food Microbiology - September 11, 2019 Category: Food Science Authors: Menezes LAA, Sardaro MLS, Duarte RTD, Mazzon RR, Neviani E, Gatti M, De Dea Lindner J Tags: Food Microbiol Source Type: research