Enrichment of Acinetobacter spp. from food samples.
This study aimed to assess whether enrichment in Dijkshoorn enrichment medium followed by plating in CHROMagar™ Acinetobacter medium is a useful method for the isolation of Acinetobacter spp. from foods. Recovery of six Acinetobacter species from food spiked with these organisms was compared for two selective enrichment media (Baumann's enrichment and Dijkshoorn's enrichment). Significantly (p 
Source: Food Microbiology - January 16, 2016 Category: Food Science Authors: Carvalheira A, Ferreira V, Silva J, Teixeira P Tags: Food Microbiol Source Type: research

Using physical approaches for the attenuation of lactic acid bacteria in an organic rice beverage.
Abstract A wild strain of Lactobacillus plantarum, isolated from an Italian sourdough, was inoculated in an organic rice drink; however, it caused a strong acidification. Thus, it was preliminary processed through homogenization (single or multiple passes) or sonication (US) and then inoculated in the beverage. The samples were stored at 4 °C and analyzed to assess pH, production of lactic acid, viable count and sensory scores. A US-2-step process (power, 80%) could control acidification; viability and sensory traits were never affected by sonication. This result was confirmed on two commercial probiotics...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Bevilacqua A, Casanova FP, Petruzzi L, Sinigaglia M, Corbo MR Tags: Food Microbiol Source Type: research

Effect of sequential dry heat and hydrogen peroxide treatment on inactivation of Salmonella Typhimurium on alfalfa seeds and seeds germination.
This study suggests that sequential treatment with dry heat and hydrogen peroxide is applicable for reducing levels of Salmonella on seeds while simultaneously enhancing seeds germinability. PMID: 26678124 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Hong EJ, Kang DH Tags: Food Microbiol Source Type: research

Spoilage of vacuum-packed beef by the yeast Kazachstania psychrophila.
This study demonstrates for the first time, that the psychrotolerant yeast K. psychrophila is a dominant spoilage microorganism of vacuum-packed beef products stored at low temperatures, causing sensory defects which result in reduced shelf life, and consequently in considerable economic losses. PMID: 26678125 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Kabisch J, Erl-Höning C, Wenning M, Böhnlein C, Gareis M, Pichner R Tags: Food Microbiol Source Type: research

Evidence for synergistic activity of plant-derived essential oils against fungal pathogens of food.
Abstract The antifungal activities of eight essential oils (EOs) namely basil, cinnamon, eucalyptus, mandarin, oregano, peppermint, tea tree and thyme were evaluated for their ability to inhibit growth of Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus and Penicillium chrysogenum. The antifungal activity of the EOs was assessed by the minimum inhibitory concentration (MIC) using 96-well microplate analysis. The interactions between different EO combinations were done by the checkerboard technique. The highest antifungal activity was exhibited by oregano and thyme which showed lower MIC values amongs...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Hossain F, Follett P, Dang Vu K, Harich M, Salmieri S, Lacroix M Tags: Food Microbiol Source Type: research

Enological characterization of Spanish Saccharomyces kudriavzevii strains, one of the closest relatives to parental strains of winemaking and brewing Saccharomyces cerevisiae × S. kudriavzevii hybrids.
In this study, we explored the genetic diversity and fermentation performance of Spanish S. kudriavzevii strains, which we compared to other S. kudriavzevii strains. Fermentations of red and white grape musts were performed, and the phenotypic differences between Spanish S. kudriavzevii strains under different temperature conditions were examined. An ANOVA analysis suggested striking similarity between strains for glycerol and ethanol production, although a high diversity of aromatic profiles among fermentations was found. The sources of these phenotypic differences are not well understood and require furthe...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Peris D, Pérez-Través L, Belloch C, Querol A Tags: Food Microbiol Source Type: research

Conventional curing practices reduce generic Escherichia coli and Salmonella spp. on dry bulb onions produced with contaminated irrigation water.
Abstract Food Safety Modernization Act (FSMA) has emphasized microbial risks associated with irrigation water. Treasure Valley (eastern Oregon/western Idaho) has the highest yield of dry bulb onions in the country; however, their irrigation water is often non-compliant with current industry and proposed federal standards for fresh produce. Conventional curing practices may provide a mechanism to mitigate irrigation water quality to comply with FSMA regulations. Dry bulb onions were grown in Owyhee silt loam and Semiahmoo muck soils in greenhouses and irrigated with water containing a cocktail of rifampicin-resista...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Emch AW, Waite-Cusic JG Tags: Food Microbiol Source Type: research

Inactivation of Salmonella Senftenberg, Salmonella Typhimurium and Salmonella Tennessee in peanut butter by 915 MHz microwave heating.
This study evaluated the efficacy of a 915 MHz microwave with 3 different levels to inactivate 3 serovars of Salmonella in peanut butter. Peanut butter inoculated with Salmonella enterica serovar Senftenberg, S. enterica serovar Typhimurium and S. enterica serovar Tennessee were treated with a 915 MHz microwave with 2, 4 and 6 kW and acid and peroxide values and color changes were determined after 5 min of microwave heating. Salmonella populations were reduced with increasing treatment time and treatment power. Six kW 915 MHz microwave treatment for 5 min reduced these three Salmonella serovar...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Song WJ, Kang DH Tags: Food Microbiol Source Type: research

Diversity and enumeration of halophilic and alkaliphilic bacteria in Spanish-style green table-olive fermentations.
ba JL Abstract The presence and enumeration of halophilic and alkaliphilic bacteria in Spanish-style table-olive fermentations was studied. Twenty 10-tonne fermenters at two large manufacturing companies in Spain, previously studied through both culture dependent and independent (PCR-DGGE) methodologies, were selected. Virtually all this microbiota was isolated during the initial fermentation stage. A total of 203 isolates were obtained and identified based on 16S rRNA gene sequences. They belonged to 13 bacterial species, included in 11 genera. It was noticeable the abundance of halophilic and alkaliphilic lactic...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Lucena-Padrós H, Ruiz-Barba JL Tags: Food Microbiol Source Type: research

Control of Shigatoxin-producing Escherichia coli in cheese by dairy bacterial strains.
Abstract Bio-preservation could be a valuable way to control Shigatoxin-producing Escherichia coli (STEC) in cheese. To this end, 41 strains were screened for their inhibitory potential on model cheese curd and on pasteurized and raw milk uncooked pressed cheeses. Strains of Lactococcus lactis, Lactococcus garvieae, Leuconostoc pseudomesenteroides, Leuconostoc citreum, Lactobacillus sp, Carnobacterium mobile, Enterococcus faecalis, Enterococcus faecium, Macrococcus caseolyticus and Hafnia alvei reduced STEC O26:H11 counts by 1.4-2.5 log cfu g(-1) and to a lesser extent STEC O157:H7 counts in pasteur...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Callon C, Arliguie C, Montel MC Tags: Food Microbiol Source Type: research

Survival of potential probiotic lactic acid bacteria on fermented green table olives during packaging in polyethylene pouches at 4 and 20 °C.
Survival of potential probiotic lactic acid bacteria on fermented green table olives during packaging in polyethylene pouches at 4 and 20 °C. Food Microbiol. 2016 Feb;53(Pt B):71-5 Authors: Blana VA, Polymeneas N, Tassou CC, Panagou EZ Abstract The survival of selected lactic acid bacteria (LAB) with in vitro probiotic potential was studied during storage of cv. Halkidiki green olives previously subjected to inoculated Spanish-style fermentation. After fermentation olives were packed in polyethylene pouches, covered with freshly prepared brine (9%, w/v, NaCl), acidified with 2‰ (w...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Blana VA, Polymeneas N, Tassou CC, Panagou EZ Tags: Food Microbiol Source Type: research

Modelling biofilm formation of Salmonella enterica ser. Newport as a function of pH and water activity.
Abstract The effect of pH and water activity (aw) on the formation of biofilm by Salmonella enterica ser. Newport, previously identified as a strong biofilm producer, was assessed. Biofilm formation was evaluated in tryptone soy broth at 37 °C and at different combinations of pH (3.3-7.8) and aw (0.894-0.997). In total, 540 biofilm formation tests in 108 pH and aw combinations were carried out in polystyrene microtiter plates using crystal violet staining and optical density (OD; 580 nm) measurements. Since the individual effects of pH and aw on biofilm formation had a similar pattern to that observe...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Dimakopoulou-Papazoglou D, Lianou A, Koutsoumanis KP Tags: Food Microbiol Source Type: research

Egg white versus Salmonella Enteritidis! A harsh medium meets a resilient pathogen.
Jan S Abstract Salmonella enterica serovar Enteritidis is the prevalent egg-product-related food-borne pathogen. The egg-contamination capacity of S. Enteritidis includes its exceptional survival capability within the harsh conditions provided by egg white. Egg white proteins, such as lysozyme and ovotransferrin, are well known to play important roles in defence against bacterial invaders. Indeed, several additional minor proteins and peptides have recently been found to play known or potential roles in protection against bacterial contamination. However, although such antibacterial proteins are well studied, litt...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Baron F, Nau F, Guérin-Dubiard C, Bonnassie S, Gautier M, Andrews SC, Jan S Tags: Food Microbiol Source Type: research

Microbial evolution of traditional mountain cheese and characterization of early fermentation cocci for selection of autochtonous dairy starter strains.
Abstract The microbial population of Traditional Mountain (TM) cheese was investigated and characterized for the selection of cocci suitable for developing new starter cultures. Samples of milk, curd and cheese at different ripening times were enumerated in selective culture media and 640 colonies were isolated from curd and cheese after 24 h of ripening. The Lactic Acid Bacteria (LAB) isolated from M17 were clustered into 231 biotypes by RAPD-PCR analysis and identified as Lactococcus lactis, Streptococcus thermophilus and Enterococcus faecalis. Forty percent of enterococci showed the in vitro ability t...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Carafa I, Clementi F, Tuohy K, Franciosi E Tags: Food Microbiol Source Type: research

Salmonella and Campylobacter: Antimicrobial resistance and bacteriophage control in poultry.
Abstract Salmonella and Campylobacter are major causes of foodborne related illness and are traditionally associated with consuming undercooked poultry and/or consuming products that have been cross contaminated with raw poultry. Many of the isolated Salmonella and Campylobacter that can cause disease have displayed antimicrobial resistance phenotypes. Although poultry producers have reduced on-the-farm overuse of antimicrobials, antimicrobial resistant Salmonella and Campylobacter strains still persist. One method of bio-control, that is producing promising results, is the use of lytic bacteriophages. This review...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Grant A, Hashem F, Parveen S Tags: Food Microbiol Source Type: research

Lactic acid bacteria in dried vegetables and spices.
In this study, we enumerated LAB in 104 spices and dried vegetables products aimed for the food manufacturing industry. The products were obtained from a spice wholesaler operating in Finland, and were sampled during a one-year period. We picked isolates (n = 343) for species identification based on numerical analysis of their ribotyping patterns and comparing them with the corresponding patterns of LAB type strains. We found LAB at levels>2 log CFU/g in 68 (65%) of the samples, with the highest counts detected from dried onion products and garlic powder with counts ranging from 4.24 to 6.64 log...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Säde E, Lassila E, Björkroth J Tags: Food Microbiol Source Type: research

Development of a model describing the inhibitory effect of selected preservatives on the growth of Listeria monocytogenes in a meat model system.
The objective of this study was to evaluate the impact of seven independent factors consisting of sodium nitrite, pH, sodium chloride, sodium acetate, sodium lactate syrup, calcium propionate and a blend of nisin and hop alpha acids on the growth rate of Listeria monocytogenes in ham as a model of ready-to-eat (RTE) meat products. A central composite consisted of seven factors mentioned above was designed and the response surface methodology was applied for creating a mathematic model to predict the growth rate of L. monocytogenes in RTE meat products. Six parameters showed a significant (P ≤ 0.1) influen...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Dussault D, Vu KD, Lacroix M Tags: Food Microbiol Source Type: research

Microbial community assessment of mealworm larvae (Tenebrio molitor) and grasshoppers (Locusta migratoria migratorioides) sold for human consumption.
Abstract In Western countries, the popularity of edible insects as an alternative animal protein source is increasing. Nevertheless, there is a lack of profound insight into the microbial safety and shelf life of living insects sold for human consumption. The purpose of this study was to characterise the microflora of fresh edible mealworm larvae and grasshoppers in a quantitative and qualitative way. Therefore, culture-dependent analyses (the total viable aerobic count, Enterobacteriaceae, lactic acid bacteria, yeasts and moulds, and bacterial endospores) and next-generation sequencing (454amplicon pyrosequencing...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Stoops J, Crauwels S, Waud M, Claes J, Lievens B, Van Campenhout L Tags: Food Microbiol Source Type: research

Effect of yeast strain and some nutritional factors on tannin composition and potential astringency of model wines.
Abstract Nine Saccharomyces cerevisiae cultures, isolated from different sources, were tested for their ability to reduce tannins reactive towards salivary proteins, and potentially responsible for wine astringency. Strains were preliminary genetically characterized and evaluated for physiological features of technological interest. Laboratory-scale fermentations were performed in three synthetic media: CT) containing enological grape tannin; CTP) CT supplemented with organic nitrogen sources; CTPV) CTP supplemented with vitamins. Adsorption of total tannins, tannins reactive towards salivary proteins, yellow pigm...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Rinaldi A, Blaiotta G, Aponte M, Moio L Tags: Food Microbiol Source Type: research

The challenge of enumerating Listeria monocytogenes in food.
Abstract Listeria monocytogenes is recognised as a serious foodborne pathogen in humans. However, food products are usually contaminated at low levels (i.e.
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Auvolat A, Besse NG Tags: Food Microbiol Source Type: research

The effects of citrus extract (Citrox(©)) on the naturally occurring microflora and inoculated pathogens, Bacillus cereus and Salmonella enterica, in a model food system and the traditional Greek yogurt-based salad Tzatziki.
The effects of citrus extract (Citrox(©)) on the naturally occurring microflora and inoculated pathogens, Bacillus cereus and Salmonella enterica, in a model food system and the traditional Greek yogurt-based salad Tzatziki. Food Microbiol. 2016 Feb;53(Pt B):150-5 Authors: Tsiraki MI, Savvaidis IN Abstract The antimicrobial effect of citrus extract (at 1 mL/kg [TC1] and 2 mL/kg [TC2]) on the naturally occurring microflora and inoculated pathogens (Bacillus cereus and Salmonella enterica, at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki during storage under v...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Tsiraki MI, Savvaidis IN Tags: Food Microbiol Source Type: research

Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain.
ita R Abstract A total of 55 enterococci (45 Enterococcus faecium, 7 Enterococcus faecalis, and three Enterococcus durans) isolated from the meat of wild game animals (roe deer, boar, rabbit, pheasant, and pigeon) in North-Western Spain were tested for susceptibility to 14 antimicrobials by the disc diffusion method. All strains showed a multi-resistant phenotype (resistance to between three and 10 antimicrobials). The strains exhibited high percentages of resistance to erythromycin (89.1%), tetracycline (67.3%), ciprofloxacin (92.7%), nitrofurantoin (67.3%), and quinupristin-dalfopristin (81.8%). The lowest value...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Guerrero-Ramos E, Cordero J, Molina-González D, Poeta P, Igrejas G, Alonso-Calleja C, Capita R Tags: Food Microbiol Source Type: research

Inactivation kinetics of Listeria monocytogenes and Salmonella enterica serovar Typhimurium on fresh-cut bell pepper treated with slightly acidic electrolyzed water combined with ultrasound and mild heat.
Abstract The goal of this study was to enhance the antimicrobial effect of slightly acidic electrolyzed water (SAEW) through addition of synergistic treatment with ultrasound (US) and mild heat treatment in order to improve the microbial safety of fresh-cut bell pepper. To evaluate the synergistic effects, the Weibull model was used to mathematically measure the effectiveness of the individual and combined treatments against Listeria monocytogenes and Salmonella Typhimurium on the pepper. The combined treatment (SAEW+US+60 °C) resulted in the TR values of 0.04 and 0.09 min for L. monocytogenes a...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Luo K, Oh DH Tags: Food Microbiol Source Type: research

Characterization of yeasts isolated from artisanal short-ripened cows' cheeses produced in Galicia (NW Spain).
al JI, Centeno JA Abstract A total of 143 presumptive yeast isolates were obtained from the predominant microflora of 21 short-ripened starter-free raw cow's milk cheeses made in Galicia (NW Spain), and the following 68 isolates were identified by both genotyping and sequencing methods: Yarrowia lipolytica (21 isolates), Kluyveromyces lactis (18), Debaryomyces hansenii (11), Pichia guilliermondii (11), Pichia fermentans (4) and Saccharomyces cerevisiae (3). Of these, Y. lipolytica and K. lactis displayed the strongest extracellular proteolytic activity on skim milk agar, and none of the D. hansenii ...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Atanassova MR, Fernández-Otero C, Rodríguez-Alonso P, Fernández-No IC, Garabal JI, Centeno JA Tags: Food Microbiol Source Type: research

Volatile chemical spoilage indexes of raw Atlantic salmon (Salmo salar) stored under aerobic condition in relation to microbiological and sensory shelf lives.
uk HG Abstract The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 °C in relation to microbial and sensory shelf lives. The volatile organic compounds (VOCs) were analyzed with SPME-GC-MS technique. Through multivariate chemometric method, hierarchical cluster analysis (HCA) and Pearson's correlations, the CSIs: trimethylamine (TMA), ethanol (EtOH), 3-methyl-1-butanol (3Met-1But), acetoin and acetic acid (C2) were selected from the group of 28 detec...
Source: Food Microbiology - December 19, 2015 Category: Food Science Authors: Mikš-Krajnik M, Yoon YJ, Ukuku DO, Yuk HG Tags: Food Microbiol Source Type: research

Editorial.
Authors: PMID: 26611163 [PubMed - as supplied by publisher] (Source: Food Microbiology)
Source: Food Microbiology - November 28, 2015 Category: Food Science Tags: Food Microbiol Source Type: research

Streptococcus thermophilus, an emerging and promising tool for heterologous expression: Advantages and future trends.
Abstract Streptococcus thermophilus is the second most used bacterium in dairy industry. It is daily consumed by millions of people through the worldwide consumption of yogurts, cheeses and fermented milks. S. thermophilus presents many features that make it a good candidate for the production of heterologous proteins. First, its ability to be naturally transformable allows obtaining swiftly and easily recombinant strains using various genetic tools available. Second, its Generally Recognised As Safe status and its ability to produce beneficial molecules or to liberate bioactive peptides from milk proteins op...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Lecomte X, Gagnaire V, Lortal S, Dary A, Genay M Tags: Food Microbiol Source Type: research

Exopolysaccharides produced by Oenococcus oeni: From genomic and phenotypic analysis to technological valorization.
Abstract Oenococcus oeni (O. oeni), which is the main species that drives malolactic fermentation (FML), an essential step for wine microbial stabilization and quality improvement, is known to produce exopolysaccharides (EPS). Depending on the strain, these EPS can be soluble, remain attached to the cell or both. In the present study, fourteen strains were examined for eps gene content and EPS production capacities. Cell-linked and soluble heteropolysaccharides made of glucose, galactose and rhamnose, soluble β-glucan, and soluble dextran or levan were found, depending on the strain. The protective potential ...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Dimopoulou M, Bardeau T, Ramonet PY, Miot-Certier C, Claisse O, Doco T, Petrel M, Lucas P, Dols-Lafargue M Tags: Food Microbiol Source Type: research

Use of the dynamic gastro-intestinal model TIM to explore the survival of the yogurt bacterium Streptococcus thermophilus and the metabolic activities induced in the simulated human gut.
In this study, we screened 30 S. thermophilus strains for urease, small heat shock protein, and amino-acid decarboxylase functions which may play a role in survival in the upper part of the GIT. The survival kinetics of 4 strains was investigated using the TIM, a physiologically relevant in vitro dynamic gastric and small intestinal model. The three strains LMD9, PB18O and EBLST20 showed significantly higher survival than CNRZ21 in all digestive compartments of the TIM, which may be related to the presence of urease and heat shock protein functions. When LMD9 bacterial cells were delivered in a fermented milk for...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Uriot O, Galia W, Awussi AA, Perrin C, Denis S, Chalancon S, Lorson E, Poirson C, Junjua M, Le Roux Y, Alric M, Dary A, Blanquet-Diot S, Roussel Y Tags: Food Microbiol Source Type: research

Survival of cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract.
rme P Abstract A mixture of nine microorganisms (six bacteria and three yeasts) from the microflora of surface-ripened cheeses were subjected to in vitro digestive stress in a three-compartment "dynamic gastrointestinal digester" (DIDGI). We studied the microorganisms (i) grown separately in culture medium only (ii) grown separately in culture medium and then mixed, (iii) grown separately in culture medium and then included in a rennet gel and (iv) grown together in smear-ripened cheese. The yeasts Geotrichum candidum, Kluyveromyces lactis and Debaryomyces hansenii, were strongly resistant to the wh...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Adouard N, Magne L, Cattenoz T, Guillemin H, Foligné B, Picque D, Bonnarme P Tags: Food Microbiol Source Type: research

Sourdough microbial community dynamics: An analysis during French organic bread-making processes.
Abstract Natural sourdoughs are commonly used in bread-making processes, especially for organic bread. Despite its role in bread flavor and dough rise, the stability of the sourdough microbial community during and between bread-making processes is debated. We investigated the dynamics of lactic acid bacteria (LAB) and yeast communities in traditional organic sourdoughs of five French bakeries during the bread-making process and several months apart using classical and molecular microbiology techniques. Sourdoughs were sampled at four steps of the bread-making process with repetition. The analysis of microbial dens...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Lhomme E, Urien C, Legrand J, Dousset X, Onno B, Sicard D Tags: Food Microbiol Source Type: research

Biofilms of Lactobacillus plantarum and Lactobacillus fermentum: Effect on stress responses, antagonistic effects on pathogen growth and immunomodulatory properties.
Abstract Few studies have extensively investigated probiotic functions associated with biofilms. Here, we show that strains of Lactobacillus plantarum and Lactobacillus fermentum are able to grow as biofilm on abiotic surfaces, but the biomass density differs between strains. We performed microtiter plate biofilm assays under growth conditions mimicking to the gastrointestinal environment. Osmolarity and low concentrations of bile significantly enhanced Lactobacillus spatial organization. Two L. plantarum strains were able to form biofilms under high concentrations of bile and mucus. We used the agar well-diffusio...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Aoudia N, Rieu A, Briandet R, Deschamps J, Chluba J, Jego G, Garrido C, Guzzo J Tags: Food Microbiol Source Type: research

Immunomodulation properties of multi-species fermented milks.
Deutsch SM Abstract Dairy propionibacteria (PAB) are used as a ripening starter in combination with Lactic acid bacteria (LAB) for dairy products such as Swiss-type cheese. LAB and PAB have also been studied for their probiotic properties but little is still known about their individual and/or synergistic beneficial effects within dairy matrices. In the context of a rising incidence of Inflammatory Bowel Diseases, it has become crucial to evaluate the immunomodulatory potential of bacteria ingested in large numbers via dairy products. We therefore selected different strains and combinations of technological LAB a...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Foligné B, Parayre S, Cheddani R, Famelart MH, Madec MN, Plé C, Breton J, Dewulf J, Jan G, Deutsch SM Tags: Food Microbiol Source Type: research

Inhibition mechanism of Listeria monocytogenes by a bioprotective bacteria Lactococcus piscium CNCM I-4031.
et MF Abstract Listeria monocytogenes is a pathogenic Gram positive bacterium and the etiologic agent of listeriosis, a severe food-borne disease. Lactococcus piscium CNCM I-4031 has the capacity to prevent the growth of L. monocytogenes in contaminated peeled and cooked shrimp. To investigate the inhibititory mechanism, a chemically defined medium (MSMA) based on shrimp composition and reproducing the inhibition observed in shrimp was developed. In co-culture at 26 °C, L. monocytogenes was reduced by 3-4 log CFU g(-1) after 24 h. We have demonstrated that the inhibition was not due to secretion of e...
Source: Food Microbiology - November 28, 2015 Category: Food Science Authors: Saraoui T, Fall PA, Leroi F, Antignac JP, Chéreau S, Pilet MF Tags: Food Microbiol Source Type: research

Antiviral effects of grape seed extract against feline calicivirus, murine norovirus, and hepatitis A virus in model food systems and under gastric conditions.
The objectives of this study were to determine (1) time and dose-dependence of GSE against FCV-F9, MNV-1, and HAV at room temperature (RT) and 37 °C over 24 h; and (2) GSE effects in model foods (apple juice (AJ) and 2% milk) and simulated gastric conditions at 37 °C. Viruses at ∼5 log PFU/ml were treated with 0.5-8 mg/ml GSE prepared in water, AJ, milk or gastric juices, or water over 24 h at RT or 37 °C. Infectivity of triplicate treatments was evaluated using plaque assays. GSE effects increased with time and concentration. GSE at 1 mg/ml in AJ reduced MNV-1 t...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Joshi SS, Su X, D'Souza DH Tags: Food Microbiol Source Type: research

Quantitative detection of Toxoplasma gondii in tissues of experimentally infected turkeys and in retail turkey products by magnetic-capture PCR.
Abstract Magnetic-capture PCR was applied for the quantitative detection of Toxoplasma gondii in tissues of experimentally infected turkeys and retail turkey meat products. For experimental infection, three T. gondii strains (ME49, CZ-Tiger, NED), varying infectious doses in different matrices (organisms in single mouse brains or 10(3), 10(5), or 10(6) oocysts in buffer) were used. From all animals, breast, thigh, and drumstick muscle tissues and for CZ-Tiger-infected animals additionally brains and hearts were analyzed. Using the magnetic-capture PCR large volumes of up to 100 g were examined. Our resul...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Koethe M, Straubinger RK, Pott S, Bangoura B, Geuthner AC, Daugschies A, Ludewig M Tags: Food Microbiol Source Type: research

Microbiota and metabolome of un-started and started Greek-type fermentation of Bella di Cerignola table olives.
This study aimed to utilize an "omics" approach to evaluate the ability of selected lactobacilli and yeasts to improve the fermentation process of Bella di Cerignola table olives. Four types of fermentations were performed at the pilot-plant scale: un-started fermented olives used as a control (Ctrl); olives started with a commercial Lactobacillus plantarum strain (S); commercial L. plantarum strain and autochthonous yeast Wickeramomyces anomalus DiSSPA73 (SY); and L. plantarum, W. anomalus DiSSPA73, autochthonous L. plantarum DiSSPA1A7 and Lactobacillus pentosus DiSSPA7 (SYL). Compared to Ctr...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: De Angelis M, Campanella D, Cosmai L, Summo C, Rizzello CG, Caponio F Tags: Food Microbiol Source Type: research

Transfer, composition and technological characterization of the lactic acid bacterial populations of the wooden vats used to produce traditional stretched cheeses.
Abstract The biofilms of 12 wooden vats used for the production of the traditional stretched cheeses Caciocavallo Palermitano and PDO Vastedda della valle del Belìce were investigated. Salmonella spp. and Listeria monocytogenes were never detected. Total coliforms were at low numbers with Escherichia coli found only in three vats. Coagulase-positive staphylococci (CPS) were below the enumeration limit, whereas lactic acid bacteria (LAB) dominated the surfaces of all vats. In general, the dominance was showed by coccus LAB. Enterococci were estimated at high numbers, but usually between 1 and 2 Log cycles lo...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Scatassa ML, Gaglio R, Macaluso G, Francesca N, Randazzo W, Cardamone C, Di Grigoli A, Moschetti G, Settanni L Tags: Food Microbiol Source Type: research

Bacteriophage cocktail significantly reduces or eliminates Listeria monocytogenes contamination on lettuce, apples, cheese, smoked salmon and frozen foods.
Abstract ListShield™, a commercially available bacteriophage cocktail that specifically targets Listeria monocytogenes, was evaluated as a bio-control agent for L. monocytogenes in various Ready-To-Eat foods. ListShield™ treatment of experimentally contaminated lettuce, cheese, smoked salmon, and frozen entrèes significantly reduced (p 
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Perera MN, Abuladze T, Li M, Woolston J, Sulakvelidze A Tags: Food Microbiol Source Type: research

Short-term response of different Saccharomyces cerevisiae strains to hyperosmotic stress caused by inoculation in grape must: RT-qPCR study and metabolite analysis.
Abstract During the winemaking process, glycerol synthesis represents the first adaption response of Saccharomyces cerevisiae to osmotic stress after inoculation in grape must. We have implemented an RT-qPCR (Reverse Transcription-quantitative PCR) methodology with a preventive evaluation of candidate reference genes, to study six target genes related to glycerol synthesis (GPD1, GPD2, GPP2 and GPP1) and flux (STL1 and FPS1), and three ALD genes coding for aldehyde dehydrogenase involved in redox equilibrium via acetate production. The mRNA level in three strains, characterized by different metabolite production, ...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Noti O, Vaudano E, Pessione E, Garcia-Moruno E Tags: Food Microbiol Source Type: research

Comparative inhibitory effects of Thymus vulgaris L. essential oil against Staphylococcus aureus, Listeria monocytogenes and mesophilic starter co-culture in cheese-mimicking models.
ni M, de Souza EL Abstract In the present study, we assessed the effects of Thymus vulgaris L. essential oil (TVEO) on Staphylococcus aureus and Listeria monocytogenes, pathogenic bacteria frequently associated with fresh or low-ripened cheeses (e.g., Brazilian coalho cheese), and on a starter co-culture comprising Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris, which are commonly used for the production of different cheeses. To measure these effects, we determined the minimum inhibitory concentration (MIC) and assessed bacterial cell viability over time in (coalho) cheese-based broth and in a...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: de Carvalho RJ, de Souza GT, Honório VG, de Sousa JP, da Conceição ML, Maganani M, de Souza EL Tags: Food Microbiol Source Type: research

House microbiotas as sources of lactic acid bacteria and yeasts in traditional Italian sourdoughs.
This study aimed at understanding the extent of contamination by lactic acid bacteria (LAB) and yeasts from the house microbiotas during sourdough back-slopping. Besides sourdoughs, wall, air, storage box, dough mixer and flour of four bakeries were analyzed. Based on plate counts, LAB and yeasts dominated the house microbiota. Based on high throughput sequencing of the 16S rRNA genes, flour harbored the highest number of Firmicutes, but only few of them adapted to storage box, dough mixer and sourdough. Lactobacillus sanfranciscensis showed the highest abundance in dough mixer and sourdoughs. Lactobacillus plantarum persi...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Minervini F, Lattanzi A, De Angelis M, Celano G, Gobbetti M Tags: Food Microbiol Source Type: research

Influence of sub-lethal stresses on the survival of lactic acid bacteria after spray-drying in orange juice.
Abstract The demand for new functional non-dairy based products makes the production of a probiotic orange juice powder an encouraging challenge. However, during drying process and storage, loss of viability of the dried probiotic cultures can occur, since the cells are exposed to various stresses. The influence of sub-lethal conditions of temperature, acidic pH and hydrogen peroxide on the viability of Pediococcus acidilactici HA-6111-2 and Lactobacillus plantarum 299v during spray drying in orange juice and subsequent storage under different conditions was investigated. At the end of storage, the survival of bot...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Barbosa J, Borges S, Teixeira P Tags: Food Microbiol Source Type: research

Inactivation of a diverse set of shiga toxin-producing Escherichia coli in ground beef by high pressure processing.
This study demonstrates the heterogeneity of STEC resistance to HPP. Risk assessors and the food industry can use this information to provide safer meat products to consumers. PMID: 26338120 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Sheen S, Cassidy J, Scullen B, Sommers C Tags: Food Microbiol Source Type: research

Quantifying the effect of sorbic acid, heat and combination of both on germination and outgrowth of Bacillus subtilis spores at single cell resolution.
Abstract Bacillus subtilis spores are a problem for the food industry as they are able to survive preservation processes. The spores often reside in food products, where their inherent protection against various stress treatments causes food spoilage. Sorbic acid is widely used as a weak acid preservative in the food industry. Its effect on spore germination and outgrowth in a combined, 'hurdle', preservation setting has gained limited attention. Therefore, the effects of mild sorbic acid (3 mM), heat-treatment (85 °C for 10 min) and a combination of both mild stresses on germination and outgrow...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Pandey R, Pieper GH, Beek AT, Vischer NO, Smelt JP, Manders EM, Brul S Tags: Food Microbiol Source Type: research

Analysis of the cellulose synthase operon genes, bcsA, bcsB, and bcsC in Cronobacter species: Prevalence among species and their roles in biofilm formation and cell-cell aggregation.
In this study the distribution and prevalence of cellulose synthase operon genes (bcsABZC) were determined by polymerase chain reaction (PCR) analysis in 231 Cronobacter strains isolated from clinical, food, environmental, and unknown sources. Furthermore, bcsA and bcsB isogenic mutants were constructed in Cronobacter sakazakii BAA894 to determine their roles. In calcofluor binding assays bcsA and bcsB mutants did not produce cellulose, and their colonial morphotypes were different to that of the parent strain. Biofilm formation and bacterial cell-cell aggregation were significantly reduced in bcsA and bcsB mutants compare...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Hu L, Grim CJ, Franco AA, Jarvis KG, Sathyamoorthy V, Kothary MH, McCardell BA, Tall BD Tags: Food Microbiol Source Type: research

Understanding the bacterial communities of hard cheese with blowing defect.
In this study, Denaturing Gradient Gel Electrophoresis (DGGE), a quantitative Clostridium tyrobutyricum PCR and next-generation Illumina-based sequencing of 16S rRNA gene were applied to study 83 Grana Padano spoiled samples. The aim was to investigate the community of clostridia involved in spoilage, the ecological relationships with the other members of the cheese microbiota, and the effect of lysozyme. Three main genera were dominant in the analysed cheeses, Lactobacillus, Streptococcus and Clostridium, and the assignment at the species level was of 94.3% of 4,477,326 high quality sequences. C. tyrobutyricum and C....
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Bassi D, Puglisi E, Cocconcelli PS Tags: Food Microbiol Source Type: research

Evaluation of survival of murine norovirus-1 during sauerkraut fermentation and storage under standard and low-sodium conditions.
ard J Abstract Sodium reduction strategies have raised a few concerns in regards to possible outbreaks in unpasteurised raw fermented vegetables. Among potential outbreak agents, foodborne viruses are recognized as an important cause of food-borne illnesses. As most of them are acid-resistant, evaluation of the efficacy of lactic fermentation in inactivating enteric viruses must be considered to ensure the safety of these foods. In particular with the sodium reduction trend which could impair adequate fermentation in vegetables, we have challenged sauerkraut fermentation at a final concentration of 4 log TCID50/mL...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Gagné MJ, Barrette J, Savard T, Brassard J Tags: Food Microbiol Source Type: research

Estimation of Listeria monocytogenes survival during thermoultrasonic treatments in non-isothermal conditions: Effect of ultrasound on temperature and survival profiles.
A, Palou E Abstract Estimation of Listeria monocytogenes survival during thermoultrasonic treatments in non-isothermal conditions was determined considering an increment from 45 to 70 °C, assessing the adequacy of predictions through experimental data obtained in laboratory media model systems. In order to characterize the sonication effect on the survival pattern, observed behavior was compared to that obtained when only thermal treatment was applied. A noticeable impact on L. monocytogenes survival in non-isothermal conditions was observed when heat is combined with ultrasound, since the sonication eff...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Franco-Vega A, Ramírez-Corona N, López-Malo A, Palou E Tags: Food Microbiol Source Type: research

Hypotheses on the effects of enological tannins and total red wine phenolic compounds on Oenococcus oeni.
aud-Funel A Abstract Lot of articles report on the impact of polyphenols on wine lactic acid bacteria, but it is clear that the results still remain confusing, because the system is complicated both in term of chemical composition and of diversity of strains. In addition, red wines polyphenols are multiple, complex and reactive molecules. Moreover, the final composition of wine varies according to grape variety and to extraction during winemaking. Therefore it is nearly impossible to deduce their effects on bacteria from experiments in oversimplified conditions. In the present work, effect of tannins preparations,...
Source: Food Microbiology - September 6, 2015 Category: Food Science Authors: Chasseriaud L, Krieger-Weber S, Déléris-Bou M, Sieczkowski N, Jourdes M, Louis Teissedre P, Claisse O, Lonvaud-Funel A Tags: Food Microbiol Source Type: research