Project description:Propionibacterium freudenreichii, a dairy starter, reaches a population close to 10^9 propionibacteria per gram of Swiss-type cheese at the time of consumption. Also consumed as a probiotic, it revealed strain-dependent anti-inflammatory properties mediated by proteins inducing IL-10 in leukocytes. Here, strains with varied anti-inflammatory potentials were compared in terms of transcriptome profiles.
Project description:Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. It produces flavor compounds over the whole ripening period. During cheese ripening, P. freudenreichii is exposed to a temperature downshift, especially when cheeses are transferred from warm temperature (about 24°C) to cold temperature (about 4°C). The cold adaptation of the type strain was studied previously. The aim of this study was to investigate the adaptation of 6 other P. freudenreichii strains at cold temperature by means of a global gene expression profile. The temporal transcriptomic response of 6 P. freudenreichii strains was analyzed at 2 times of growth, during growth at 30°C then after 3 days 4°C, in the constant presence of lactate as the main carbon source.
Project description:The intra sub-species diversity of six strains of Lactococcus lactis subsp. lactis was investigated at the genomic level and in terms of phenotypic and transcriptomic profiles in UF-cheese model. Six strains were isolated from various sources, but all are exhibiting a dairy phenotype. Our results showed that, the six strains exhibited small phenotypic differences since similar behaviour in terms of growth was obtained during cheese ripening while only different acidification capability was detected. Even if all strains displayed high genomic similarities, sharing a high core genome of almost two thousands genes, the expression of this core genome directly in the cheese matrix revealed major strain-specific differences. This strains with the same dairy origin.
Project description:The intra sub-species diversity of six strains of Lactococcus lactis subsp. lactis was investigated at the genomic level and in terms of phenotypic and transcriptomic profiles in UF-cheese model. Six strains were isolated from various sources, but all are exhibiting a dairy phenotype. Our results showed that, the six strains exhibited small phenotypic differences since similar behaviour in terms of growth was obtained during cheese ripening while only different acidification capability was detected. Even if all strains displayed high genomic similarities, sharing a high core genome of almost two thousands genes, the expression of this core genome directly in the cheese matrix revealed major strain-specific differences. This strains with the same dairy origin.
Project description:RNA-seq was used in combination with various analytical chemistry approaches to identify the chemical and genetic basis of pigment production of the bacterium Glutamicibacter arilaitensis when growing on cheese. This bacterium commonly found in cheese rinds where it co-occurs with Penicillium species and other molds. Pinkish-red pigments are produced by the bacterium in response to growth with Penicillium. Both chemical analyses and RNA-seq point to coproporphyrin III as the major metabolite leading to pigment formation.
Project description:Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. It produces flavor compounds over the whole ripening period. During cheese ripening, P. freudenreichii is exposed to a temperature downshift, especially when cheeses are transferred from warm temperature (about 24M-BM-0C) to cold temperature (about 4M-BM-0C). The cold adaptation of the type strain was studied previously. The aim of this study was to investigate the adaptation of 6 other P. freudenreichii strains at cold temperature by means of a global gene expression profile. The temporal transcriptomic response of 6 P. freudenreichii strains was analyzed at 2 times of growth, during growth at 30M-BM-0C then after 3 days 4M-BM-0C, in the constant presence of lactate as the main carbon source. Six strains were used: CIRM-BIA9, CIRM-BIA118, CIRM-BIA122, CIRM-BIA123, CIRM-BIA472, CIRM-BIA482. Gene expression was measured in the middle of exponential growth phase at 30M-BM-0C (20h, OD650 M-bM-^IM-^H 0.5), and after 3days of incubation at 4M-BM-0C. Three independent biological experiments were performed for each strain and at each time, and were labelled A, B, C. Five technical repetitions were performed using the RNA of 3J_122B, 3J_123A, 3J_472C, 20H_9A and 20H_482C samples. These technical repetitions were labelled 3J_122Bii, 3J_123Aii, 3J_472Cii, 20H_9Aii and 20H_482Cii respectively. The transcriptomic data for 20H_122A and 3J_123C samples were abberant and were thus not considered for further analysis.
Project description:The cheese microbial community is dense with relatively low complexity and composed of cultivable prokaryotic and eukaryotic microorganisms. The ripening process can thus be reproduced under controlled conditions. A reduced microbial community composed of yeasts and bacteria was assembled to mimic that of smear-ripened cheese. The genomes of the microorganisms have been sequenced and annotated, which allows access to gene expression under various conditions at different ripening times. Through the use of a combined approach using omics (e.g. metatranscriptomics, volatilomics), and biochemical/microbial analyses, we have investigated the effect of a biotic perturbation, omission of some yeast, on the stability and functionality of the microbial cheese community throughout ripening.
Project description:This is the first metaproteomics-based featuring of the microbial community harbured in the traditional raw milk Caprino Nicastrese cheese