References of "International Journal of Food Microbiology"
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See detailEvaluation of viability and growth of Acetobacter senegalensis under different stress conditions
Shafiei, Rasoul ULg; Thonart, Philippe ULg; Delvigne, Frank ULg et al

in International Journal of Food Microbiology (2013)

Acetic acid bacteria (AAB) are used in production of vinegars. During acetic acid fermentation, AAB encounter various aggressive conditions which may lead to a variety of cellular disorders. Previous ... [more ▼]

Acetic acid bacteria (AAB) are used in production of vinegars. During acetic acid fermentation, AAB encounter various aggressive conditions which may lead to a variety of cellular disorders. Previous researches mainly studied the influences of different carbon sources on tolerance of AAB to ethanol and acetic acid. In this study, different techniques were used comparatively to investigate the effects of preadaptation on the ability of A. senegalensis to tolerate ethanol and acetic acid. In general, the carbon sources used for preadaptation of A. senegalensis exhibited significant effects on the tolerance of cells to stressors. Flow-cytometric assessments of preadapted cells in ethanol showed that 87.3% of the cells perform respiration after exposure to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid. However, 58.4% of these preadapted cells could keep their envelope integrity under the stress condition. They could also grow rapidly (μmax = 0.39/h) in the stress medium (E5A3) with a high yield (>80%). A. senegalensis grown in glucose exhibited a low tolerance to acetic acid. Analysis of their respiration capacity, membrane integrity and culturability revealed that almost all the population were dead after exposure to 5% (v/v) ethanol and 3% (w/v) acetic acid. In contrast, exposure of A. senegalensis preadapted in a mixture of glucose and acetic acid to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid, exhibited an intact respiration system and cellular membrane integrity in 80.3% and 50.01% of cells, respectively. Moreover, just 24% of these cells could keep their culturability under that stress condition. [less ▲]

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See detailPresence of Clostridium difficile in pigs and cattle intestinal contents and carcass contamination at the slaughterhouse in Belgium.
Rodriguez Diaz, Cristina ULg; Avesani, V.; Van Broeck, J. et al

in International Journal of Food Microbiology (2013), 166(2), 256-262

The objective of this study was to evaluate the presence of Clostridium difficile in intestinal and carcass samples collected from pigs and cattle at a single slaughterhouse. C. difficile was isolated in ... [more ▼]

The objective of this study was to evaluate the presence of Clostridium difficile in intestinal and carcass samples collected from pigs and cattle at a single slaughterhouse. C. difficile was isolated in 1% and 9.9% of the pig and cattle intestinal contents and in 7.9% and 7% of cattle and pig carcass samples respectively. A total of 19 different PCR-ribotypes were identified, among them types 078 and 014. Seven of 19 ribotypes correlated with the PCR-ribotypes involved in human C. difficile infections in Belgium. This study confirms that animals are carriers of C. difficile at slaughter and ribotypes are identical than those in humans, and that carcass contamination occurs inside the slaughterhouse. [less ▲]

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See detailIdentification of surf actin producing strains in Soumbala and Bikalga fermented condiments using polymerase chain reaction and matrix assisted laser desorption/ionization-mass spectrometry methods
Savadogo, A; Tapi, Arthur; Chollet, Marlène et al

in International Journal of Food Microbiology (2011)

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See detailA Box-Behnken Design For Predicting The Combined Effects Of Relative Humidity And Temperature On Antagonistic Yeast Population Density At The Surface Of Apples
Lahlali, Rachid; Massart, Sébastien ULg; Serrhini, Mn. et al

in International Journal of Food Microbiology (2008), 122(1-2), 100-108

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See detailUse of Lactobacillus strains to start cassava fermentations for Gari production
Huch, M.; Hanak, A.; Specht, I. et al

in International Journal of Food Microbiology (2008), 128(2), 258-267

Two Lactobacillus strains, Lactobacillus plantarum BFE 6710 and Lactobacillus fermentum BFE 6620, were used to start cassava fermentations in a pilot study under field production conditions in Kenya, to ... [more ▼]

Two Lactobacillus strains, Lactobacillus plantarum BFE 6710 and Lactobacillus fermentum BFE 6620, were used to start cassava fermentations in a pilot study under field production conditions in Kenya, to determine their potential to establish themselves as predominant lactobacilli during the fermentation. Predominant strains from three fermentations were isolated throughout the 48 h fermentation period. The use of these strains in high numbers clearly resulted in 1 to 2 log higher lactic acid bacteria (LAB) counts over the course of the fermentation when compared to the uninoculated control. 178 predominant LAB isolates were grouped based on their phenotypic characteristics, and were characterised to strain level by RAPD–PCR, followed by PFGE strain typing. Overall, L. plantarum strains represented the majority of the isolates, followed by Weissella confusa and Lactococcus garvieae strains. The results of RAPD–PCR and PFGE strain typing techniques indicated that L. plantarum BFE 6710 was successful in asserting itself as a predominant strain. In contrast, L. fermentum BFE 6620 failed to establish itself as a predominant organism in the fermentation. The success of the L. plantarum strains to predominate in the cassava fermentation demonstrates the potential for development of Lactobacillus starter cultures to industrialise the Gari production process. [less ▲]

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See detailCharacterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures
Kostinek, M.; Specht, I.; Edward, V. A. et al

in International Journal of Food Microbiology (2007), 114(3), 342-351

A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into ... [more ▼]

A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, p-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H2O2-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of the 32 a total of 16 strains were finally selected for the development as starter cultures for Gari production. (C) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailA seven-year survey of Campylobacter contamination in meat at different production stages in Belgium
Ghafir, Yasmine; China, Bernard; Dierick, Katelijne et al

in International Journal of Food Microbiology (2007), 116(1), 35-45

The presence of Campylobacter was assessed in different samples of poultry, pork and beef meat and carcasses from slaughterhouses, production plants and retail level. An introductory study from 1997 to ... [more ▼]

The presence of Campylobacter was assessed in different samples of poultry, pork and beef meat and carcasses from slaughterhouses, production plants and retail level. An introductory study from 1997 to 1999, had the purpose of establishing the optimum dilution to detect changes in prevalence and allowed a semi-quantitative estimation of poultry and pork contamination. Following this, between 2000 and 2003, 4254 samples were taken in order to study the trends. The poultry matrixes represented the greatest number and the most highly contaminated samples, with 30.9% (in 0.01 g) positive samples, 18.7% (in 1 g), 46.9% (in 25 g) and 19.6% (in 0.01 g) for broiler carcasses, broiler fillets, prepared chicken and layer carcasses, respectively. Broiler carcasses and fillets sampled at retail level were significantly less contaminated than samples from production plants. Pork, beef and veal samples were rarely contaminated and, where contamination existed, it was at a low prevalence (maximum 5.0%). The high and unvarying prevalence of Campylobacter in poultry necessitates the implementation of intervention measures at the primary production level, in addition to methods of minimizing cross-contamination at the processing level. A survey plan in line with the present study could be used in the future to monitor the effects of the planned measures and performance objectives and to follow the evolution of Campylobacter contamination at all stages of the food chain, in accordance with European legislation. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailPredictive Modelling Of Temperature And Water Activity (Solutes) On The In Vitro Radial Growth Of Botrytis Cinerea Pers
Lahlali, R.; Serrhini, Mn.; Friel, D. et al

in International Journal of Food Microbiology (2007), 114(1), 1-9

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See detailQuantitative risk assessment of Campylobacter spp. in poultry based meat preparations as one of the factors to support the development of risk-based microbiological criteria in Belgium
Uyttendaele, Mieke; Baert, Katleen; Ghafir, Yasmine et al

in International Journal of Food Microbiology (2006), 111(2), 149-163

The objective of this study was to do an exercise in risk assessment on Campylobaeter spp. for poultry based meat preparations in Belgium. This risk assessment was undertaken on the demand of the ... [more ▼]

The objective of this study was to do an exercise in risk assessment on Campylobaeter spp. for poultry based meat preparations in Belgium. This risk assessment was undertaken on the demand of the competent national authorities as one of the supportive factors to define fisk-based microbiological criteria. The quantitative risk assessment model follows a retail to table approach and is divided in different modules. The contamination of raw chicken meat products (CMPs) was represented by a normal distribution of the natural logarithm of the concentration of Campylobacter spp. (In[Camp]) in raw CMPs based on data from surveillance programs in Belgium. To analyse the relative impact of reducing the risk of campylobacteriosis associated with a decrease in the Campylobacter contamination level in these types of food products, the model was run for different means and standard deviations of the normal distribution of the ln[Camp] in raw CMPs. The limitation in data for the local situation in Belgium and on this particular product and more precisely the semi-quantitative nature of concentration of Campylobacter spp. due to presence/absence testing, was identified as an important information gap. Also the knowledge on the dose-response relationship of Campylobacter spp. was limited, and therefore three different approaches of dose-response modelling were compared. Two approaches (1 and 2), derived from the same study, showed that the reduction of the mean of the distribution representing the ln[Camp] in raw CMPs is the best approach to reduce the risk of Campylobacter spp. in CMPs. However, for the simulated exposure and approach 3 it was observed that the reduction of the standard deviation is the most appropriate technique to lower the risk of campylobacteriosis. Since the dose-response models used in approach I and 2 are based on limited data and the reduction of the mean corresponds with a complete shift of the contamination level of raw CMPs, demanding high efforts from the poultry industry, it is proposed to lower the standard deviation of the concentration of Campylobacter spp. in raw CMPs. This proposal corresponds with the elimination of the products that are highly contaminated. Simulation showed that eating raw chicken meat products can give rise to exposures that are 10(10) times higher than when the product is heated, indicating that campaigns are important to inform consumers about the necessity of an appropriate heat treatment of these type of food products. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailUse of a serological approach for prediction of Salmonella status in an integrated pig production system
Korsak Koulagenko, Nicolas ULg; Degeye, Jean-Noel; Etienne, Grégory et al

in International Journal of Food Microbiology (2006), 108(2), 246-254

Relevance of a Salmonella serological detection technique was studied from complete results obtained from 9 pigs fattening units. Feces and overshoes were sampled at different periods after starting ... [more ▼]

Relevance of a Salmonella serological detection technique was studied from complete results obtained from 9 pigs fattening units. Feces and overshoes were sampled at different periods after starting fattening (2, 3 and 4 months) while caecal contents were taken on the slaughter line. The bacteriological technique used was based on a Diasalm enrichment and a commercial test was used for serology on an average of ten animals per batch. The aim of this work was to establish a correlation between serological results obtained at slaughter (10 samples/batch) and bacteriological results. In this context, two types of logistic regression models were tested by considering alternatively serology and Salmonella detection in caecal contents as the dependent variables. Firstly, beside the fact that all logistic regression models show weak correlations, the first finding was that positive results in overshoes taken at 2 and 3 months are slightly correlated with serological status of herds (odds-ratios of 4.96 and 2.55). Secondly, when batches were characterized as positive on the basis of serological results, the probability of Salmonella recovery in caecal contents was higher than when the batches were considered as negative (odds-ratios comprised between 4.36 and 5.81). A major conclusion is that serology can be used to follow the improvement of an integrated pig production system, but is not the unique solution for assessing risk of Salmonella shedding from specific herds. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailStudying And Modelling The Combined Effect Of Temperature And Water Activity On The Growth Rate Of P. Expansum
Lahlali, Rachid; Serrhini, Mn.; Jijakli, Mohamed ULg

in International Journal of Food Microbiology (2005), 103(3), 315-322

The effect of solutes, water activity (aw, 0.890–0.980) and temperature (5–25 8C) on the mycelial growth rate of Penicillium expansum was evaluated. The growth rate dropped as the temperature and aw of ... [more ▼]

The effect of solutes, water activity (aw, 0.890–0.980) and temperature (5–25 8C) on the mycelial growth rate of Penicillium expansum was evaluated. The growth rate dropped as the temperature and aw of the medium decreased. NaCl was the solute causing the greatest growth rate reduction, followed by glucose, glycerol and sorbitol. Statistical analysis of the results showed a significant effect of solute, aw, temperature and combinations of two or three of these factors ( P b0.0001). Whatever the solutes and aw values, the initiation of colony growth required an additional day at 15 8C and 5 8C as compared to initiation at 25 8C. Growth models based on the results obtained with sorbitol and glycerol differed only slightly, with R2 values of 97.00% and 97.95%, respectively. The response surfaces of both quadratic polynomial models showed that P. expansum should be able to grow at low aw (0.890) and that growth at 25 8C should be fastest at aw values ranging from 0.960 to 0.980. Both models presented a good fit between predicted and observed values. [less ▲]

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See detailInteraction of an odorant lactone with model phospholipid bilayers and its strong fluidizing action in yeast membrane.
Aguedo, Mario ULg; Beney, Laurent; Wache, Yves et al

in International journal of food microbiology (2002), 80(3), 211-5

Some odorant lactones are naturally present in fruits or in fermented products; they can also be used as food additives and can be produced by microorganisms at the industrial scale by biotechnological ... [more ▼]

Some odorant lactones are naturally present in fruits or in fermented products; they can also be used as food additives and can be produced by microorganisms at the industrial scale by biotechnological processes. Gamma-decalactone was previously shown to have antimicrobial properties. We determined by infrared spectroscopy measurements that this compound rapidly diffused into model phospholipid bilayers (within 2 min), modifying the general physical state of a dimyristoyl-L-alpha-phosphatidylcholine (DMPC) film. In vivo, the lactone strongly increased membrane fluidity in the model yeast Yarrowia lipolytica, as evaluated by fluorescence anisotropy measurements. This effect was more important than that of benzyl alcohol, which is known as a fluidizing agent in living cells, and may explain the toxic action of gamma-decalactone in microorganisms. [less ▲]

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