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Einar Ringo - One of the best experts on this subject based on the ideXlab platform.
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search Article Open Access
2016Co-Authors: Reidar Myklebust, Mads Kristiansen, Daniel L. Merrifield, Jose Gonzalez L. Vecino, Einar RingoAbstract:In the present study the impact on gut microbiology and indigenous gut histology of Atlantic salmon (Salmo salar L.) was investigated following feeding of a control and a prebiotic (EWOS prebiosal®) diet and ex vivo exposure to saline or the probiotic bacterium Carnobacterium divergens. The results showed that ex vivo exposure of C. divergens at 108 CFU ml-1 did not cause cell damage to the intestine tract of Atlantic salmon. Furthermore, prior provision of dietary prebiotic elevated the ability of C. divergens to adhere to the epithelium or mucus layer in the proximal intestine, where culturable heterotrophic bacterial levels (which were identified as C. divergens) were elevated by 234 % compared to the control. This effect was not apparent in the distal intestine. The ability of isolated carnobacteria from the ex vivo experiment to inhibit growth of two fish pathogenic bacteria (Yersinia rückeri and Aeromonas salmonicida ssp. salmonicida) was assessed. Extracellular products from all 11 of the isolated carnobacteria strains, plus the type strain Carnobacterium inhibens CCUG 31728, inhibited the in vitro growth of Y. rückeri. However, only extracellular products from C. divergens isolate 57 inhibited the growth of A. salmonicid
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Evaluation of Prebiotic and Probiotic Effects on the Intestinal Gut Microbiota and Histology of Atlantic salmon (Salmo salar L.)
Journal of Aquaculture Research and Development, 2011Co-Authors: Mads Kristiansen, Reidar Myklebust, Daniel L. Merrifield, Jose Gonzalez L. Vecino, Einar RingoAbstract:In the present study the impact on gut microbiology and indigenous gut histology of Atlantic salmon ( Salmo salar L.) was investigated following feeding of a control and a prebiotic (EWOS prebiosal ® ) diet and ex vivo exposure to saline or the probiotic bacterium Carnobacterium divergen s. The results showed that ex vivo exposure of C. divergens at 10 8 CFU ml -1 did not cause cell damage to the intestine tract of Atlantic salmon. Furthermore, prior provision of dietary prebiotic elevated the ability of C. divergens to adhere to the epithelium or mucus layer in the proximal intestine, where culturable heterotrophic bacterial levels (which were identified as C. divergens ) were elevated by 234% compared to the control. This effect was not apparent in the distal intestine. The ability of isolated carnobacteria from the ex vivo experiment to inhibit growth of two fish pathogenic bacteria ( Yersinia ruckeri and Aeromonas salmonicida ssp. salmonicida ) was assessed. Extracellular products from all 11 of the isolated carnobacteria strains, plus the type strain Carnobacterium inhibens CCUG 31728, inhibited the in vitro growth of Y. ruckeri . However, only extracellular products from C. divergens isolate 57 inhibited the growth of A. salmonicida ssp. salmonicida .
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characterisation of the microbiota associated with intestine of atlantic cod gadus morhua l the effect of fish meal standard soybean meal and a bioprocessed soybean meal
Aquaculture, 2006Co-Authors: Einar Ringo, Sigmund Sperstad, Reidar Myklebust, Stale Refstie, Ashild KrogdahlAbstract:Abstract Populations of aerobic heterotrophic bacteria present in the gastrointestinal (GI) tract of healthy Atlantic cod (Gadus morhua L.) fed three different diets, fish meal, standard or a bioprocessed soybean meal (BPSBM), were estimated using the dilution plate technique. A total of 944 isolates were characterised by biochemical and physiological properties and 425 isolates were identified further by sequencing the 16S rRNA genes. Our results showed that gut microbiota were affected by dietary manipulation. The GI tract of fish fed fish meal was dominated by Gram-positive bacteria of the genera Brochothrix and Carnobacterium. The Gram-negative bacteria Chryseobacterium spp. and Psychrobacter glacincola, and Gram-positive bacteria belonging to Carnobacterium, dominated in the digestive tract of fish fed soybean meal. In contrast to these results, genus Psychrobacter dominated in the GI tract when fish were fed BPSBM. Until recently, it was generally suggested that the gut microbiota of fish were less diverse than in homoeothermic animals. However, the present study identified several “new” bacterial species isolated from the alimentary tract of Atlantic cod. These “new” bacterial species are not normally isolated from the GI tract of fish. Based on our finding we suggest that the GI tract microbiota of fish might not be as simple as believed. Antagonistic activity of carnobacteria regarding inhibition of growth of two fish pathogens (Aeromonas salmonicida ssp. salmonicida and Vibrio anguillarum) was observed. However, some difference in the antibacterial activity of Carnobacterium spp. was observed. Whether this antagonistic activity has any effect in challenge studies will be discussed, especially in relation to the finding that the digestive tract is one of the major infection routes in fish.
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the effect of dietary inulin on aerobic bacteria associated with hindgut of arctic charr salvelinus alpinus l
Aquaculture Research, 2006Co-Authors: Einar Ringo, Sigmund Sperstad, T M Mayhew, Reidar Myklebust, Rolf Erik OlsenAbstract:The primary aim of the present study was to evaluate the population level of adherent (autochthonous) aerobic and facultative anaerobic bacteria in the hindgut of healthy Arctic charr (Salvelinus alpinus L.) fed dextrin or inulin. This was assessed by the dilution plate technique, and visualized using both transmission and scanning electron microscopy. A population level of 4.8 × 105 adherent bacteria per gram wet mass was found in the hindgut of fish fed a casein-based diet supplemented with 15% dextrin. However, substituting dextrin with 15% inulin reduced the bacterial population level in the hindgut (3.56 × 104). A total of 217 bacterial isolates were identified by key phenotypical and biochemical characteristics. In addition, 22 strains were also identified by partial sequencing of the 16S rRNA gene. The composition of bacteria colonizing the hindgut of Arctic charr fed dextrin was dominated by the genera Staphylococcus, Pseudomonas, Micrococcus, Psychrobacter glacincola and Streptococcus. However, bacteria colonizing the hindgut of fish fed inulin were dominated by Gram-positive bacteria of the genera Staphylococcus, Streptococcus, Carnobacterium and Bacillus. While Carnobacterium divergens-like strains were isolated from charr fed dextrin, Carnobacterium maltaromicus-like strains were isolated from the hindgut of fish fed inulin. Electron microscopical analysis of hindgut regions confirmed traditional culture-based microbial analysis as fewer bacterial cells were observed between microvilli and associated with the surfaces of enterocytes of fish fed inulin rather than dextrin.
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Characterization of Carnobacterium divergens strain 6251 isolated from intestine of Arctic charr (Salvelinus alpinus L.).
Systematic and applied microbiology, 2002Co-Authors: Einar Ringo, Rolf Erik Olsen, Marit Seppola, Anita Berg, Ulrich Schillinger, Wilhelm H. HolzapfelAbstract:Summary An atypical strain of Carnobacterium divergens , strain 6251, was isolated from the small intestine of Arctic charr ( Salvelinus alpinus L.), fed high dietary carbohydrate. This strain showed marked growth inhibitory effects in vitro against the fish pathogens Aeromonas salmonicida subsp. salmonicida (furunculosis), Vibrio anguillarum (vibriosis) and Vibrio viscocus (winter ulcer). The strain is a non-motile Gram-positive psychrotrophic rod that lacks both catalase and oxidase, grows at pH 9.1 (CTAS agar), but not on acetate containing media (pH ≤ 5.4), on TCBS or at ≤6% sodium chloride content. Strain 6251 is facultatively anaerobic and utilises tryptone as a sole source of nutrient. Further characterisation showed the most abundant cellular fatty acid of strain 6251 to be oleic acid (18:1) (n-9) (36.0%). Sequencing of a 16S rDNA region of 578 nucleotides and AFLP TM microbial fingerprinting suggested that strain 6251 is not closely related to any carnobacteria known, however, DNA-DNA similarity determinations showed high similarity (96.2%) with the type strain of Carnobacterium divergens . The unique phenotypic attributes of this strain represent new information on the biodiversity and ecology of carnobacteria and especially of the species C. divergens .
Francoise Leroi - One of the best experts on this subject based on the ideXlab platform.
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lactic acid bacteria selection for biopreservation as a part of hurdle technology approach applied on seafood
Frontiers in Marine Science, 2017Co-Authors: M. F. Pilet, Norman Wiernasz, Delphine Passerini, Josiane Cornet, Mireille Cardinal, Francoise LeroiAbstract:As fragile food commodities, microbial and organoleptic qualities of fishery and seafood can quickly deteriorate. In this context, microbial quality and security improvement during the whole food processing chain (from catch to plate), using hurdle technology, a combination of mild preserving technologies such as biopreservation, modified atmosphere packaging and superchilling, are of great interest. Thirty-five lactic acid bacteria (LAB) belonging to the species Carnobacterium maltaromaticum, Carnobacterium inhibens, Lactococcus piscium, Leuconostoc gelidum, Vagococcus fluvialis, Vagococcus penaei and Aerococcus viridans, known to possess interesting antimicrobial activity, were chosen for their potential application as bioprotective agents as a part of hurdle technology applied to fishery products. The selection approach was based on 7 criteria including antimicrobial activity, alteration potential, resistance to chitosan coating and superchilling process, cross inhibition, biogenic amines production (histamine, tyramine) and antibiotics resistance. Antimicrobial activity was assessed against 6 common spoiling bacteria in fishery products (Shewanella baltica, Photobacterium phosphoreum, Brochothrix thermosphacta, Lactobacillus sakei, Hafnia alvei, Serratia proteamaculans) and 1 pathogenic bacteria (Listeria monocytogenes) in co-culture inhibitory assays miniaturized in 96-well microtiter plates. Antimicrobial activity and spoilage evaluation, both performed in cod and salmon juice, highlighted the existence of sensory signatures and inhibition profiles, which seem to be species related. Finally 6 LAB with no unusual antibiotics resistance profile nor histamine production ability were selected as bioprotective agents for further in situ inhibitory assays in cod and salmon based products, alone or in combination with other hurdles (chitosan, modified atmosphere packing and superchilling).
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effect of inoculation of Carnobacterium divergens v41 a biopreservative strain against listeria monocytogenes risk on the microbiological chemical and sensory quality of cold smoked salmon
International Journal of Food Microbiology, 2005Co-Authors: Anne Brillet, M. F. Pilet, Hervé Prévost, Mireille Cardinal, Francoise LeroiAbstract:The aim of this study was to develop a biopreservation strategy for cold-smoked salmon (CSS) by the use of lactic acid bacteria previously selected for their capability to inhibit the growth of Listeria monocytogenes in the product. The spoiling potential of three Carnobacterium strains (Carnobacterium divergens V41, Carnobacterium piscicola V1 and SF668) was tested in sterile CSS blocks inoculated by 104-5 CFU g− 1 and stored under vacuum for 9 days at 4 °C followed by 19 days at 8 °C. C. divergens V41 grew a little faster than the other strains and none of the three carnobacteria showed any adverse effect on quality of the product, i.e. no off-odour detected by a trained panel, no total volatile basic nitrogen (TVBN) production, no acidification and no biogenic amine except a slight production of tyramine. An application on commercial CSS was tested by spraying C. divergens V41 (104-5 CFU g− 1) on slices of four batches freshly processed in different smokehouses. Microbial, chemical and sensory characteristics were weekly compared to a control during 4 weeks of vacuum storage. When the natural microflora was initially weak (two batches 104-5 CFU g− 1), no effect on the microflora, TVBN and biogenic amine production, nor on the sensory characteristics was observed in presence of C. divergens V41. In conclusion, biopreservation of CSS using lactic acid bacteria such as C. divergens V41 is a promising way to inhibit the growth of pathogenic bacteria such as L. monocytogenes with low effect on the quality of the product.
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biodiversity of listeria monocytogenes sensitivity to bacteriocin producing Carnobacterium strains and application in sterile cold smoked salmon
Journal of Applied Microbiology, 2004Co-Authors: Anne Brillet, M. F. Pilet, A Bouttefroy, Hervé Prévost, Francoise LeroiAbstract:Aims: The aim of this study was to demonstrate the inhibitory capacity of Carnobacterium strains against a collection of Listeria monocytogenes strains in cold-smoked salmon (CSS). Methods and Results: Three bacteriocin-producing strains, Carnobacterium divergens V41, C. piscicola V1 and C. piscicola SF668, were screened for their antilisterial activity against a collection of 57 L. monocytogenes strains selected from the French smoked salmon industry, using an agar spot test. All the Listeria strains were inhibited but three different groups could be distinguished differing in sensitivity to the three Carnobacterium strains. However, C. divergens V41 always had the highest inhibitory effect. The antilisterial capacity was then tested in sterile CSS blocks co-inoculated with Carnobacterium spp. and mixtures of L. monocytogenes strains. C. divergens V41 was the most efficient strain, maintaining the level of L. monocytogenes at <50 CFU g−1 during the 4 weeks of vacuum storage at 4 and 8°C, whatever the sensitivity of the set of L. monocytogenes strains. Conclusions: C. divergens V41 may be a good candidate for biopreservation in CSS. Significance and Impact of the Study: A biopreservation strategy for CSS against the risk of L. monocytogenes was investigated using bacteriocin-producing lactic acid bacteria.
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inhibition of listeria monocytogenes by in situ produced and semipurified bacteriocins of Carnobacterium spp on vacuum packed refrigerated cold smoked salmon
Journal of Food Protection, 1999Co-Authors: Frédérique Duffes, Francoise Leroi, Xavier Dousset, C Corre, P BoyavalAbstract:Listeria monocytogenes inhibition by Carnobacterium strains and crude bacteriocins on sterile and commercial vacuum-packed cold-smoked salmon stored at 4°C and 8°C was investigated. Carnobacterium piscicola V1 was bactericidal against L. monocytogenes at the two temperatures, whereas Carnobacterium divergens V41 presented a bacteriostatic effect. C. piscicola SF668 delayed L. monocytogenes growth at 8°C and had a bacteriostatic effect at 4°C. Listeria growth was not affected by a non-bacteriocin-producing C. piscicola. Crude extracts of piscicocins were bactericidal at 4°C and 8°C. Listeria growth was delayed by divercin V41 at 8°C and was inhibited at 4°C. Nisin delayed Listeria growth at 8°C and was bacteriostatic at 4°C. The present study demonstrates that L. monocytogenes growth could be prevented on vacuum-packed cold-smoked salmon by Carnobacterium and associated bacteriocins at chilled temperatures. Moreover, no product spoilage could be observed with the use of such bacteriocin-producing strains as demonstrated by good sensorial analyses and low biogenic amine production.
Hervé Prévost - One of the best experts on this subject based on the ideXlab platform.
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Draft Genome Sequence of Carnobacterium divergens V41, a Bacteriocin-Producing Strain
Genome Announcements, 2016Co-Authors: Benoit Remenant, M. F. Pilet, Anne Marie Revol-junelles, Hervé Prévost, Laurent Marché, Frederic Borges, Catherine Cailliez-grimal, Aurélie Lajus, Claudine Médigue, Monique ZagorecAbstract:In this study, we present the draft genome sequence of Carnobacterium divergens V41. This strain was previously reported as producing divercin V41, a bacteriocin of interest for food biopreservation. Its genome revealed also the presence of a gene cluster putatively involved in polyketide production, which is unique in lactic acid bacteria.
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Complete chromosome sequence of Carnobacterium maltaromaticum LMA 28.
Genome announcements, 2013Co-Authors: C Cailliez-Grimal, J Anba-Mondoloni, M I Afzal, V. Loux, Anne Marie Revol-junelles, Peter Dalgaard, Jorgen J Leisner, Sylvain Chaillou, Gilles Kergourlay, Monique Zagorec, Hervé Prévost, A Rahman, Marie Christine Champomier Vergès, Fernanda BorgesAbstract:Within the lactic acid bacterium genus Carnobacterium, Carnobacterium maltaromaticum is one of the most frequently isolated species from natural environments and food. It potentially plays a major role in food product biopreservation. We report here on the 3.649-Mb chromosome sequence of C. maltaromaticum LMA 28, which was isolated from ripened soft cheese.
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First published online August 2007. DOI:10.1111/j.1574-6976.2007.00080.x
2007Co-Authors: Jorgen J Leisner, Hervé Prévost, Paw Dalgaard, Djamel Drider, Birgit Groth Laursen, Díaz OrejasAbstract:food spoilage; food safety; probiotics. The genus Carnobacterium contains nine species, but only C. divergens and C. maltaromaticum are frequently isolated from natural environments and foods. They are tolerant to freezing/thawing and high pressure and able to grow at low temperatures, anaerobically and with increased CO2 concentrations. They metabolize arginine and various carbohydrates, including chitin, and this may improve their survival in the environment. Carnobacterium divergens and C. maltaromaticum have been extensively studied as protective cultures in order to inhibit growth of Listeria monocytogenes in fish and meat products. Several carnobacterial bacteriocins are known, and parameters that affect their production have been described. Currently, however, no isolates are commercially applied as protective cultures. Carnobacteria can spoil chilled foods, but spoilage activity shows intraspecies and interspecies variation. The responsible spoilage metabolites ar
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effect of inoculation of Carnobacterium divergens v41 a biopreservative strain against listeria monocytogenes risk on the microbiological chemical and sensory quality of cold smoked salmon
International Journal of Food Microbiology, 2005Co-Authors: Anne Brillet, M. F. Pilet, Hervé Prévost, Mireille Cardinal, Francoise LeroiAbstract:The aim of this study was to develop a biopreservation strategy for cold-smoked salmon (CSS) by the use of lactic acid bacteria previously selected for their capability to inhibit the growth of Listeria monocytogenes in the product. The spoiling potential of three Carnobacterium strains (Carnobacterium divergens V41, Carnobacterium piscicola V1 and SF668) was tested in sterile CSS blocks inoculated by 104-5 CFU g− 1 and stored under vacuum for 9 days at 4 °C followed by 19 days at 8 °C. C. divergens V41 grew a little faster than the other strains and none of the three carnobacteria showed any adverse effect on quality of the product, i.e. no off-odour detected by a trained panel, no total volatile basic nitrogen (TVBN) production, no acidification and no biogenic amine except a slight production of tyramine. An application on commercial CSS was tested by spraying C. divergens V41 (104-5 CFU g− 1) on slices of four batches freshly processed in different smokehouses. Microbial, chemical and sensory characteristics were weekly compared to a control during 4 weeks of vacuum storage. When the natural microflora was initially weak (two batches 104-5 CFU g− 1), no effect on the microflora, TVBN and biogenic amine production, nor on the sensory characteristics was observed in presence of C. divergens V41. In conclusion, biopreservation of CSS using lactic acid bacteria such as C. divergens V41 is a promising way to inhibit the growth of pathogenic bacteria such as L. monocytogenes with low effect on the quality of the product.
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biodiversity of listeria monocytogenes sensitivity to bacteriocin producing Carnobacterium strains and application in sterile cold smoked salmon
Journal of Applied Microbiology, 2004Co-Authors: Anne Brillet, M. F. Pilet, A Bouttefroy, Hervé Prévost, Francoise LeroiAbstract:Aims: The aim of this study was to demonstrate the inhibitory capacity of Carnobacterium strains against a collection of Listeria monocytogenes strains in cold-smoked salmon (CSS). Methods and Results: Three bacteriocin-producing strains, Carnobacterium divergens V41, C. piscicola V1 and C. piscicola SF668, were screened for their antilisterial activity against a collection of 57 L. monocytogenes strains selected from the French smoked salmon industry, using an agar spot test. All the Listeria strains were inhibited but three different groups could be distinguished differing in sensitivity to the three Carnobacterium strains. However, C. divergens V41 always had the highest inhibitory effect. The antilisterial capacity was then tested in sterile CSS blocks co-inoculated with Carnobacterium spp. and mixtures of L. monocytogenes strains. C. divergens V41 was the most efficient strain, maintaining the level of L. monocytogenes at <50 CFU g−1 during the 4 weeks of vacuum storage at 4 and 8°C, whatever the sensitivity of the set of L. monocytogenes strains. Conclusions: C. divergens V41 may be a good candidate for biopreservation in CSS. Significance and Impact of the Study: A biopreservation strategy for CSS against the risk of L. monocytogenes was investigated using bacteriocin-producing lactic acid bacteria.
G. Nieddu - One of the best experts on this subject based on the ideXlab platform.
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Use of Carnobacterium spp protective culture in MAP packed Ricotta fresca cheese to control Pseudomonas spp
Food Microbiology, 2018Co-Authors: Carlo Spanu, A. M. Mocci, Fabrizio Piras, G. Nieddu, E P L De Santis, Christian ScaranoAbstract:Ricotta fresca is a whey cheese susceptible of secondary contamination, mainly from Pseudomonas spp. The extension of the shelf life of refrigerated ricotta fresca could be obtained using protective cultures inhibiting the growth of this spoilage microorganism. A commercial biopreservative, Lyofast CNBAL, comprising Carnobacterium spp was tested against Pseudomonas spp. The surface of ricotta fresca samples were inoculated either with Pseudomonas spp or Pseudomonas and Carnobacterium spp. Samples were MAP packed, stored at 4 °C and analyzed the day of the inoculum and 7, 14 and 21 days after the contamination. Microbiological analyses included total bacterial count, mesophilic lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp, Listeria monocytogenes, moulds and yeasts. Pseudomonas mean initial contamination level was comparable in blank and artificially inoculated samples, respectively with values of 2.15 ± 0.21 and 2.34 ± 0.26 log cfu g−1. Carnobacterium spp. significantly reduced the growth of Pseudomonas spp respectively of 1.28 log and 0.83 log after 14 and 21 days of refrigerated storage. Intrinsic properties and physico-chemical composition were also investigated. Limited variation of pH was observed in samples inoculated with the protective cultures, indicating low acidification properties of Carnobacterium spp. Instead, no significant differences were observed for aW, moisture, fat and proteins during storage and between inoculated and control samples.
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testing commercial biopreservative against spoilage microorganisms in map packed ricotta fresca cheese
Food Microbiology, 2017Co-Authors: Carlo Spanu, Christian Scarano, Fabrizio Piras, Vincenzo Spanu, Carlo Pala, Daniele Casti, Sonia Lamon, Francesca Cossu, Michela Ibba, G. NiedduAbstract:Abstract Ricotta fresca cheese is susceptible to secondary contamination and is able to support the growth of pathogens or spoilage psychotrophic bacteria during storage. The aim of the present study was to evaluate which among three commercial biopreservatives was suitable to be used to control the growth of spoilage microorganisms in sheep's milk MAP ricotta fresca cheese. 144 Ricotta fresca cheese samples were inoculated either with the bioprotective culture Lyofast FPR 2 (including Enterococcus faecium, Lactobacillus plantarum e Lactobacillus rhamnosus) or Lyofast CNBAL (Carnobacterium spp) or the fermentate MicroGARD 430. Not inoculated control and experimental ricotta were MAP packed (30% CO2 and 70% N2) and stored at 4 °C. Triplicate samples were analyzed after 5 h and 7, 14 and 21 days after inoculation for total bacterial count, mesophilic lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp, Listeria monocytogenes, moulds and yeasts. Among the tested biopreservatives only Carnobacterium spp was able to control Pseudomonas spp and Enterobacteriaceae. The maximum reduction in the concentration of Pseudomonas spp and Enterobacteriaceae was respectively 1.93 and 2.66 log10 cfu/g, observed 14 days after production. Therefore, Carnobacterium spp was selected as the culture of choice to conduct a challenge study against Pseudomonas spp.
Jean-bernard Millière - One of the best experts on this subject based on the ideXlab platform.
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Short communication: Carnobacterium maltaromaticum: the only Carnobacterium species in French ripened soft cheeses as revealed by polymerase chain reaction detection.
Journal of dairy science, 2007Co-Authors: Catherine Cailliez-grimal, Anne Marie Revol-junelles, H.c. Edima, Jean-bernard MillièreAbstract:The PCR technique using Cb1-Cb2R and species-specific primers was applied to various French soft flowered or washed rind cheeses to identify Carnobacterium species. Thirty cheeses made from cow's, ewe's, or goat's milk (raw or pasteurized), of which 20 were Appellation d'Origine Controlee, were analyzed in the autumn and spring. The results revealed that, irrespective of the season, the Carnobacterium genus was initially detected in 5 cheeses and was detected in 5 others after an enrichment period. Polymerase chain reaction results using species-specific primers of Carnobacterium showed that these 10 cheeses contained only the species Carnobacterium maltaromaticum. Six different patterns of fermentation were found, and 3 of the 10 cheeses contained C. maltaromaticum isolates with anti-Listeria activity.
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quantitative polymerase chain reaction used for the rapid detection of Carnobacterium species from french soft cheeses
Fems Microbiology Letters, 2005Co-Authors: Catherine Cailliezgrimal, Romaric Miguindoumabiala, Marie Leseine, Annemarie Revoljunelles, Jean-bernard MillièreAbstract:Abstract An identification method by PCR, specific to the Carnobacterium genus, was optimised by testing it on 28 bacterial strains. Primers from the literature were tested to differentiate Carnobacterium strains present among various bacterial species. The DNA of Carnobacterium species ( C. alterfunditum , C. divergens , C. funditum , C. gallinarum , C. inhibens , C. maltaromaticum , C. mobile , C. viridans ), specifically amplified by the Cb1–Cb2R primer couple at a hybridization temperature of 69 °C, gave only one band of 340 bp. The validation of this technique was carried out on a French soft cheese made with pasteurised milk inoculated with C. maltaromaticum LMA 28. Using classical PCR, detection was not possible for decimal dilutions of the cheese above 1 g L −1 . With Sybr Green I real time PCR, the specificity of the reaction was confirmed by the T m value. The standard curve constructed using the main threshold cycle and various concentrations of C. maltaromaticum LMA 28 (ranging from 10 0 to 10 8 cfu mL −1 ) showed good linearity and a sensitivity limit of ⩾10 4 cfu g −1 of cheese. This technique was applied on commercially available cheeses made from raw cow’s milk. The Sybr Green I real time PCR method constitutes an effective and easy-to-perform method to quantify Carnobacterium sp. in cheese.
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presence of Carnobacterium spp in french surface mould ripened soft cheese
Journal of Applied Microbiology, 1994Co-Authors: Jean-bernard Millière, M Michel, Florence Mathieu, Gerard LefebvreAbstract:Thirty-six ‘atypical lactobacilli’, randomly picked from five surface mould-ripened soft-cheeses, were characterized by physiological and chemical, including DNA, analyses. This homofermentative, non-aciduric and psychrotrophic group represented the major bacterial flora with counts between 108 and 109 cfu g-1. Common characteristics were the production of L-(+)-lactic acid enantiomer, the presence of meso-diaminopimelic acid in the peptidoglycan, the hydrolysis of arginine and the failure to produce acid from sorbitol. On the basis of the description of the genus Carnobacterium (Collins et al. 1987), 33 isolates were assigned to C. piscicola and three to C. divergens. Antibacterial substance production was observed for 16 isolates, with a narrow spectrum of activity. To our knowledge, this is the first report of Carnobacterium spp. in mould-ripened soft-cheese.