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Pascal Bonnarme - One of the best experts on this subject based on the ideXlab platform.
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Transcription Profiling Reveals Cooperative Metabolic Interactions in a Microbial Cheese-Ripening Community Composed of Debaryomyces hansenii, Brevibacterium aurantiacum, and Hafnia alvei
Frontiers in Microbiology, 2019Co-Authors: Nguyen-phuong Pham, Pascal Bonnarme, Sophie Landaud, Pascale Lieben, Christophe MonnetAbstract:Ripening cultures containing fungi and bacteria are widely used in Smear-Ripened Cheese production processes, but little is known about the biotic interactions of typical ripening microorganisms at the surface of Cheese. We developed a lab-scale mini-Cheese model to investigate the biotic interactions of a synthetic community that was composed of Debaryomyces hansenii, Brevibacterium aurantiacum and Hafnia alvei, three species that are commonly used for Smear-Ripened Cheese production. Transcriptomic analyses of Cheese samples produced with different combinations of these three species revealed potential mechanisms of biotic interactions concerning iron acquisition, proteolysis, lipolysis, sulfur metabolism and D-galactonate catabolism. A strong mutualistic interaction was observed between H. alvei and B. aurantiacum. We propose an explanation of this positive interaction in which B. aurantiacum would benefit from siderophore production by H. alvei, and the latter would be stimulated by the energy compounds liberated from caseins and triglycerides through the action of the proteases and lipases secreted by B. aurantiacum. In the future, it would be interesting to take the iron acquisition systems of Cheese-associated strains into account for the purpose of improving the selection of the ripening culture components and their association in mixed cultures.
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Draft genome sequence of Corynebacterium variabile Mu292, isolated from Munster, a french Smear-Ripened Cheese
Genome Announcements, 2016Co-Authors: Eric Dugat-bony, Anne-sophie Sarthou, Valentin Loux, Marie Vidal, Pascal Bonnarme, Francoise Irlinger, Séverine LayecAbstract:Here, we report the draft genome sequence of Corynebacterium variabile Mu292, which was originally isolated from the surface of Munster, a French Smear-Ripened Cheese. This genome investigation will improve our knowledge on the molecular determinants potentially involved in the adaptation of this strain during the Munster-type Cheese manufacturing process.
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Survival of Cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract
Food Microbiology, 2016Co-Authors: Nadège Adouard, Laurent Magne, Thomas Cattenoz, Hervé Guillemin, Benoît Foligné, Daniel Picque, Pascal BonnarmeAbstract: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 whole DIDGI process (with a drop in viable cell counts of less than
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Survival of Cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract
Food Microbiology, 2016Co-Authors: Nadège Adouard, Laurent Magne, Thomas Cattenoz, Hervé Guillemin, Benoît Foligné, Daniel Picque, Pascal BonnarmeAbstract: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 whole DIDGI process (with a drop in viable cell counts of less than < 1 log CFU mL(-1)) and there were no significant differences between lab cultures and Cheese-grown cultures. Ripening bacteria such as Hafnia alvei survived gastric stress less well when grown in Cheese (with no viable cells after 90 min of exposure of the Cheese matrix, compared with 6 CFU mL(-1) in lab cultures). The ability of Corynebacterium casei and Staphylococcus equorum to withstand digestive stress was similar for Cheese and pure culture conditions. When grow in a Cheese matrix, Brevibacterium aurantiacum and Arthrobacter arilaitensis were clearly more sensitive to the overall digestive process than when grown in pure cultures. Lactococcus lactis displayed poorer survival in gastric and duodenal compartments when it had been grown in Cheese. In vivo experiments in BALB/c mice agreed with the DIDGI experiments and confirmed the latter's reliability.
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In vitro characterization of the digestive stress response and immunomodulatory properties of microorganisms isolated from Smear-Ripened Cheese
International Journal of Food Microbiology, 2015Co-Authors: Nadège Adouard, Benoît Foligné, Daniel Picque, Joëlle Dewulf, Marielle Bouix, Pascal BonnarmeAbstract:Abstract Thirty-six microorganisms (twenty-one bacteria, twelve yeasts and three fungi) were isolated from surface-ripened Cheeses and subjected to in vitro digestive stress. The approach mimicked gastric and/or duodenal digestion. Lactobacillus rhamnosus GG, Escherichia coli Nissle 1917 and Saccharomyces boulardii were used as reference strains. We studied the microorganisms grown separately in culture medium and then included (or not) in a rennet gel. The microorganisms' immunomodulatory abilities were also assessed by profiling cytokine induction in human peripheral blood mononuclear cells (PBMCs). The loss of viability was less than 1 log CFU/mL for yeasts under all conditions. In contrast, Gram-negative bacteria survived gastric and/or duodenal stress well but most of the Gram-positive bacteria were more sensitive (especially to gastric stress). Inclusion of sensitive Gram-positive bacteria in rennet gel dramatically improved gastric survival, when compared with a non-included cultured (with a 4 log CFU/mL change in survival). However, the rennet gel did not protect the bacteria against duodenal stress. The PBMC cytokine assay tests showed that the response to yeasts was usually anti-inflammatory, whereas the response to bacteria varied from one strain to another.
Francoise Irlinger - One of the best experts on this subject based on the ideXlab platform.
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Secondary and Adjunct Cultures
Cheese, 2017Co-Authors: Francoise Irlinger, Sandra Helinck, Jean Luc JanyAbstract:This chapter discusses the most important groups of secondary flora, the species found in Cheeses, the properties used in their selection, and the form and use of these cultures as adjuncts. The secondary and adjunct cultures involved include yeasts—for example, Geotrichum candidum, Debaryomyces hansenii, moulds, e.g., Penicillum camemberti, P roqueforti , and bacteria—for example, Corynebacterium, Staphylococcus, Micrococcus, Propionibacterium sp. , and heterofermentative lactobacilli and are involved only in Cheese ripening. Except for Propionibacterium and the heterofermentative lactobacilli , the secondary cultures grow mainly on the Cheese surface. They are called secondary cultures to distinguish them from the primary acid-producing starters and are as important as the primary ones in those Cheeses in which they are found. The yeast flora contributes directly or indirectly to the appearance of Cheese. For example, G. candidum varies considerably from slimy cream to velvet mould-like depending on the strain. Consequently, the growth behavior of G. candidum is of great importance in choosing the correct strain for the type of Cheese being produced. The yeasts encountered on the surface of Cheese show varied abilities to metabolize sugars, lactate and citrate. Because Kluyveromyces marxianus and Debaryomyces hansenii are able to ferment lactose, their use as adjuncts is very common. G. candidum assimilates galactose and lactate, which is of paramount importance in the ripening of mould and bacterial Smear-Ripened Cheese.
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Draft genome sequence of Corynebacterium variabile Mu292, isolated from Munster, a french Smear-Ripened Cheese
Genome Announcements, 2016Co-Authors: Eric Dugat-bony, Anne-sophie Sarthou, Valentin Loux, Marie Vidal, Pascal Bonnarme, Francoise Irlinger, Séverine LayecAbstract:Here, we report the draft genome sequence of Corynebacterium variabile Mu292, which was originally isolated from the surface of Munster, a French Smear-Ripened Cheese. This genome investigation will improve our knowledge on the molecular determinants potentially involved in the adaptation of this strain during the Munster-type Cheese manufacturing process.
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Genome Sequence of Staphylococcus equorum subsp. equorum Mu2, Isolated from a French Smear-Ripened Cheese
Journal of Bacteriology, 2012Co-Authors: Francoise Irlinger, Valentin Loux, Pascal Bonnarme, Sophie Landaud, Pascal Bento, Jean-francois Gibrat, Cecile Straub, Christophe MonnetAbstract:Staphylococcus equorum subsp. equorum is a member of the coagulase-negative staphylococcus group and is frequently isolated from fermented food products and from food-processing environments. It contributes to the formation of aroma compounds during the ripening of fermented foods, especially Cheeses and sausages. Here, we report the draft genome sequence of Staphylococcus equorum subsp. equorum Mu2 to provide insights into its physiology and compare it with other Staphylococcus species.
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Genome sequence of corynebacterium casei UCMA 3821, isolated from a Smear-Ripened Cheese
Journal of Bacteriology, 2012Co-Authors: Christophe Monnet, Valentin Loux, Pascal Bonnarme, Sophie Landaud, Pascal Bento, Jean-francois Gibrat, Cecile Straub, Francoise IrlingerAbstract:Corynebacterium casei is one of the most prevalent species present on the surfaces of Smear-Ripened Cheeses, where it contributes to the production of the desired organoleptic properties. Here, we report the draft genome sequence of Corynebacterium casei UCMA 3821 to provide insights into its physiology.
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Surface microbial consortia from Livarot, a French Smear-Ripened Cheese
Canadian Journal of Microbiology, 2011Co-Authors: Sandra Larpin-laborde, Francoise Irlinger, Stefanie Goerges, Roberto Gelsomino, M Goodfellow, A C Ward, Muhammad Imran, Catherine Bonaiti, Nagamani Bora, Marc VancanneytAbstract:The surface microflora (902 isolates) of Livarot Cheeses from three dairies was investigated during ripening. Yeasts were mainly identified by Fourier transform infrared spectroscopy. Geotrichum candidum was the dominating yeast among 10 species. Bacteria were identified using Biotype 100 strips, dereplicated by repetitive extragenic palindromic PCR (rep-PCR); 156 representative strains were identified by either BOX-PCR or (GTG)(5)-PCR, and when appropriate by 16S rDNA sequencing and SDS-PAGE analysis. Gram-positive bacteria accounted for 65% of the isolates and were mainly assigned to the genera Arthrobacter, Brevibacterium, Corynebacterium, and Staphylococcus. New taxa related to the genera Agrococcus and Leucobacter were found. Yeast and Gram-positive bacteria strains deliberately added as smearing agents were sometimes undetected during ripening. Thirty-two percent of the isolates were Gram-negative bacteria, which showed a high level of diversity and mainly included members of the genera Alcaligenes, Hafnia, Proteus, Pseudomonas, and Psychrobacter. Whatever the milk used (pasteurized or unpasteurized), similar levels of biodiversity were observed in the three dairies, all of which had efficient cleaning procedures and good manufacturing practices. It appears that some of the Gram-negative bacteria identified should now be regarded as potentially useful in some Cheese technologies. The assessment of their positive versus negative role should be objectively examined.
Christophe Monnet - One of the best experts on this subject based on the ideXlab platform.
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Transcription Profiling Reveals Cooperative Metabolic Interactions in a Microbial Cheese-Ripening Community Composed of Debaryomyces hansenii, Brevibacterium aurantiacum, and Hafnia alvei
Frontiers in Microbiology, 2019Co-Authors: Nguyen-phuong Pham, Pascal Bonnarme, Sophie Landaud, Pascale Lieben, Christophe MonnetAbstract:Ripening cultures containing fungi and bacteria are widely used in Smear-Ripened Cheese production processes, but little is known about the biotic interactions of typical ripening microorganisms at the surface of Cheese. We developed a lab-scale mini-Cheese model to investigate the biotic interactions of a synthetic community that was composed of Debaryomyces hansenii, Brevibacterium aurantiacum and Hafnia alvei, three species that are commonly used for Smear-Ripened Cheese production. Transcriptomic analyses of Cheese samples produced with different combinations of these three species revealed potential mechanisms of biotic interactions concerning iron acquisition, proteolysis, lipolysis, sulfur metabolism and D-galactonate catabolism. A strong mutualistic interaction was observed between H. alvei and B. aurantiacum. We propose an explanation of this positive interaction in which B. aurantiacum would benefit from siderophore production by H. alvei, and the latter would be stimulated by the energy compounds liberated from caseins and triglycerides through the action of the proteases and lipases secreted by B. aurantiacum. In the future, it would be interesting to take the iron acquisition systems of Cheese-associated strains into account for the purpose of improving the selection of the ripening culture components and their association in mixed cultures.
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Genome Sequence of Staphylococcus equorum subsp. equorum Mu2, Isolated from a French Smear-Ripened Cheese
Journal of Bacteriology, 2012Co-Authors: Francoise Irlinger, Valentin Loux, Pascal Bonnarme, Sophie Landaud, Pascal Bento, Jean-francois Gibrat, Cecile Straub, Christophe MonnetAbstract:Staphylococcus equorum subsp. equorum is a member of the coagulase-negative staphylococcus group and is frequently isolated from fermented food products and from food-processing environments. It contributes to the formation of aroma compounds during the ripening of fermented foods, especially Cheeses and sausages. Here, we report the draft genome sequence of Staphylococcus equorum subsp. equorum Mu2 to provide insights into its physiology and compare it with other Staphylococcus species.
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Genome sequence of corynebacterium casei UCMA 3821, isolated from a Smear-Ripened Cheese
Journal of Bacteriology, 2012Co-Authors: Christophe Monnet, Valentin Loux, Pascal Bonnarme, Sophie Landaud, Pascal Bento, Jean-francois Gibrat, Cecile Straub, Francoise IrlingerAbstract:Corynebacterium casei is one of the most prevalent species present on the surfaces of Smear-Ripened Cheeses, where it contributes to the production of the desired organoleptic properties. Here, we report the draft genome sequence of Corynebacterium casei UCMA 3821 to provide insights into its physiology.
Nadège Adouard - One of the best experts on this subject based on the ideXlab platform.
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Survival of Cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract
Food Microbiology, 2016Co-Authors: Nadège Adouard, Laurent Magne, Thomas Cattenoz, Hervé Guillemin, Benoît Foligné, Daniel Picque, Pascal BonnarmeAbstract: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 whole DIDGI process (with a drop in viable cell counts of less than
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Survival of Cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract
Food Microbiology, 2016Co-Authors: Nadège Adouard, Laurent Magne, Thomas Cattenoz, Hervé Guillemin, Benoît Foligné, Daniel Picque, Pascal BonnarmeAbstract: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 whole DIDGI process (with a drop in viable cell counts of less than < 1 log CFU mL(-1)) and there were no significant differences between lab cultures and Cheese-grown cultures. Ripening bacteria such as Hafnia alvei survived gastric stress less well when grown in Cheese (with no viable cells after 90 min of exposure of the Cheese matrix, compared with 6 CFU mL(-1) in lab cultures). The ability of Corynebacterium casei and Staphylococcus equorum to withstand digestive stress was similar for Cheese and pure culture conditions. When grow in a Cheese matrix, Brevibacterium aurantiacum and Arthrobacter arilaitensis were clearly more sensitive to the overall digestive process than when grown in pure cultures. Lactococcus lactis displayed poorer survival in gastric and duodenal compartments when it had been grown in Cheese. In vivo experiments in BALB/c mice agreed with the DIDGI experiments and confirmed the latter's reliability.
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In vitro characterization of the digestive stress response and immunomodulatory properties of microorganisms isolated from Smear-Ripened Cheese
International Journal of Food Microbiology, 2015Co-Authors: Nadège Adouard, Benoît Foligné, Daniel Picque, Joëlle Dewulf, Marielle Bouix, Pascal BonnarmeAbstract:Abstract Thirty-six microorganisms (twenty-one bacteria, twelve yeasts and three fungi) were isolated from surface-ripened Cheeses and subjected to in vitro digestive stress. The approach mimicked gastric and/or duodenal digestion. Lactobacillus rhamnosus GG, Escherichia coli Nissle 1917 and Saccharomyces boulardii were used as reference strains. We studied the microorganisms grown separately in culture medium and then included (or not) in a rennet gel. The microorganisms' immunomodulatory abilities were also assessed by profiling cytokine induction in human peripheral blood mononuclear cells (PBMCs). The loss of viability was less than 1 log CFU/mL for yeasts under all conditions. In contrast, Gram-negative bacteria survived gastric and/or duodenal stress well but most of the Gram-positive bacteria were more sensitive (especially to gastric stress). Inclusion of sensitive Gram-positive bacteria in rennet gel dramatically improved gastric survival, when compared with a non-included cultured (with a 4 log CFU/mL change in survival). However, the rennet gel did not protect the bacteria against duodenal stress. The PBMC cytokine assay tests showed that the response to yeasts was usually anti-inflammatory, whereas the response to bacteria varied from one strain to another.
T M Cogan - One of the best experts on this subject based on the ideXlab platform.
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Commercial ripening starter microorganisms inoculated into Cheese milk do not successfully establish themselves in the resident microbial ripening consortia of a South german red smear Cheese.
Applied and Environmental Microbiology, 2008Co-Authors: Stefanie Goerges, Jérôme Mounier, Roberto Gelsomino, Marc Vancanneyt, T M Cogan, Mary C. Rea, Valeska Heise, Ruediger Beduhn, Siegfried SchererAbstract:Production of Smear-Ripened Cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. These microorganisms often originate from the Cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. While commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. Thus, the fate of the smear starters of a German Limburger Cheese subjected to the "old-young" smearing technique was investigated during ripening. The Cheese milk was supplemented with a commercial smear starter culture containing Debaryomyces hansenii, Galactomyces geotrichum, Arthrobacter arilaitensis, and Brevibacterium aurantiacum. Additionally, the Cheese surface was inoculated with an extremely stable in-house microbial consortium. A total of 1,114 yeast and 1,201 bacterial isolates were identified and differentiated by Fourier transform infrared spectroscopy. Furthermore, mitochondrial DNA restriction fragment length polymorphism, random amplified polymorphic DNA, repetitive PCR, and pulsed field gel electrophoresis analyses were used to type selected isolates below the species level. The D. hansenii starter strain was primarily found early in the ripening process. The G. geotrichum starter strain in particular established itself after relocation to a new ripening room. Otherwise, it occurred at low frequencies. The bacterial smear starters could not be reisolated from the Cheese surface at all. It is concluded that none of the smear starter strains were able to compete significantly and in a stable fashion against the resident microbial consortia, a result which might have been linked to the method of application. This finding raises the issue of whether addition of starter microorganisms during production of this type of Cheese is actually necessary.
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Corynebacterium mooreparkense, a later heterotypic synonym of Corynebacterium variabile.
International Journal of Systematic and Evolutionary Microbiology, 2005Co-Authors: Roberto Gelsomino, Marc Vancanneyt, Katrien Vandemeulebroecke, Bart Hoste, T M Cogan, Cindy Snauwaert, Jean SwingsAbstract:Strains of a Gram-positive bacterium were isolated from the Irish Smear-Ripened Cheese Gubbeen, and assigned to a new species, Corynebacterium mooreparkense, in 2001. During a further study on the same Cheese, no additional isolates from this species could be found. Instead, multiple isolates of its nearest phylogenetic neighbour, Corynebacterium variabile, were found. A first screening with rep-PCR and SDS-PAGE pointed to a similarity between C. mooreparkense and C. variabile. Following this peculiar result, attempts were made to collect all type strains deposited at different culture collections and all strains described by Brennan et al. [Int J Syst Evol Microbiol (2001) 51, 843-852]. Subsequently, 16S rRNA gene sequencing and DNA-DNA hybridizations were performed. All C. mooreparkense strains had a 16S rRNA gene sequence similarity of at least 99.5 % with C. variabile and the DNA-DNA relatedness was 95 %. On the basis of these results, it is concluded that C. mooreparkense is a later heterotypic synonym of C. variabile.
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Biodiversity of the bacterial flora on the surface of a smear Cheese.
Applied and Environmental Microbiology, 2002Co-Authors: Noelle M. Brennan, M Goodfellow, A C Ward, T P Beresford, P F Fox, T M CoganAbstract:The bacteria on the surface of a farmhouse Smear-Ripened Cheese at four stages of ripening (4, 16, 23, and 37 days) from inoculated (i.e., deliberately inoculated with Brevibacterium linens BL2) and noninoculated (not deliberately inoculated with B. linens BL2) Cheese were investigated. The results show that, contrary to accepted belief, B. linens is not a significant member of the surface flora of smear Cheese and no microbial succession of species occurred during the ripening of the Cheeses. Of 400 isolates made, 390 were lactate-utilizing coryneforms and 10 were coagulase-negative Staphylococcus spp. A detailed analysis of the coryneforms was undertaken using phenotypic analysis, molecular fingerprinting, chemotaxonomic techniques, and 16S rRNA gene sequencing. DNA banding profiles (ramdom amplified polymorphic DNA [RAPD]-PCR) of all the coryneform isolates showed large numbers of clusters. However, pulsed-field gel electrophoresis (PFGE) of the isolates from the Cheeses showed that all isolates within a cluster and in many contiguous clusters were the same. The inoculated and noninoculated Cheeses were dominated by single clones of novel species of Corynebacterium casei (50.2% of isolates), Corynebacterium mooreparkense (26% of isolates), and Microbacterium gubbeenense (12.8% of isolates). In addition, five of the isolates from the inoculated Cheese were Corynebacterium flavescens. Thirty-seven strains were not identified but many had similar PFGE patterns, indicating that they were the same species. C. mooreparkense and C. casei grew at pH values below 4.9 in the presence of 8% NaCl, while M. gubbeenense did not grow below pH 5.8 in the presence of 5 to 10% NaCl. B. linens BL2 was not recovered from the inoculated Cheese because it was inhibited by all the Staphylococcus isolates and many of the coryneforms. It was concluded that within a particular batch of Cheese there was significant bacterial diversity in the microflora on the surface.
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Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov., isolated from the surface of a Smear-Ripened Cheese.
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: Noelle M. Brennan, R Brown, M Goodfellow, A C Ward, T P Beresford, P F Fox, P.j. Simpson, T M CoganAbstract:Ten isolates each of two different bacterial species isolated from the surface of a Smear-Ripened Cheese were found to exhibit many characteristics of the genus Corynebacterium. The isolates were Gram-positive, catalase-positive, non-spore-forming rods that did not undergo a rod/coccus transformation when grown on complex media. Chemotaxonomic investigation revealed that the strains belonged unambiguously to the genus Corynebacterium. Their cell walls contained arabinose, galactose and short-chain mycolic acids (C22 to C36) and their peptidoglycan contained meso-diaminopimelic acid. The G+C content of the DNA was 51-60 mol%. MK-9 (H2) was the principal menaquinone. The 16S rDNA sequences of four isolates of each bacterium were determined and aligned with those of other members of the coryneform group. Phylogenetic analysis showed that the strains represented two new sublines within the genus Corynebacterium; Corynebacterium variabile and Corynebacterium ammoniagenes were their nearest known phylogenetic neighbours. Corynebacterium variabile and Corynebacterium ammoniagenes showed the highest levels of sequence homology with the isolates; however, DNA-DNA hydridization studies indicated that the Corynebacterium strains isolated from the Cheese smear did not belong to either Corynebacterium variabile or Corynebacterium ammoniagenes (26 and 46% chromosomal similarity, respectively). On the basis of the phylogenetic and phenotypic distinctiveness of the unknown isolates, it is proposed that the bacteria be classified as two new Corynebacterium species, for which the names Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov. are proposed. Type strains have been deposited in culture collections as Corynebacterium mooreparkense LMG S-19265T (= NCIMB 30131T) and Corynebacterium casei LMG S-19264T (= NCIMB 30130T).
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Microbacterium gubbeenense sp. nov., from the surface of a Smear-Ripened Cheese.
International journal of systematic and evolutionary microbiology, 2001Co-Authors: Nm Brennan, R Brown, M Goodfellow, A C Ward, T P Beresford, M Vancanneyt, T M Cogan, P F FoxAbstract:Phenotypic and phylogenetic studies were performed on 11 strains of a Microbacterium-like organism isolated from the surface of a Smear-Ripened Cheese. The isolates were Gram-positive, catalase-positive, facultatively anaerobic, oxidase-negative, non-spore-forming, non-motile, small, slender rods and grew in 12% (w/v) NaCl. Chemotaxonomic investigation revealed that all the isolates belonged unambiguously to the genus Microbacterium. They contained type B1 peptidoglycans with L-lysine as the diamino acid and glycolyl acyl types; rhamnose and galactose were the cell wall sugars. The G+C content ranged from 69 to 72 mol%. The major menaquinones were MK-11 and MK-12 and the major fatty acids were anteiso C15:0 and C17:0 and iso C16:0. Phylogenetic analysis of the 16S rRNA sequences of four isolates showed that they represented a new subline in the genus Microbacterium, with Microbacterium barkeri as their nearest phylogenetic neighbour. M. barkeri showed the highest sequence similarity to the isolates; however, DNA-DNA hybridization showed that the isolates had only 38% chromosomal similarity to M. barkeri. Based on the phylogenetic and phenotypic distinctiveness of the isolates, it is proposed that they be classified as a new Microbacterium species, for which the name Microbacterium gubbeenense sp. nov. is suggested. The type strain has been deposited as LMG S-19263T (= NCIMB 30129T). The GenBank accession number for the 16S rDNA sequence of the type strain is AF263563.