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:Effect of the presence of Lactococcus lactis on Staphylococcus aureus transcriptome in cheese matrix. S. aureus was co-cultured with L. lactis LD61 in cheese matrix during 7 days. RNA samples were extracted at different time points (6 h, 8 h, 10 h, 24 h and 7 days) in order to monitor the dynamic response of S. aureus MW2 in cheese matrix in presence of L. lactis
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 enzymatic repertoire of starter cultures is important for cheese characteristics but is challenging to characterize due to the high protein and fat concentration, and the semi-solid state of the cheese matrix. This study aimed to generate a protocol to characterize the proteome of bacteria harvested from milk and cheese, to assess the proteome differences between Lactococcus cremoris grown in milk and laboratory medium, and to investigate the proteome adaptation during cheese production and ripening.
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.
