Project description:The response of L. lactis to the presence of S. cerevisiae was analyzed during the exponential growth phase in fermentors in defined growth conditions. Although no growth kinetic difference was observed between the pure and mixed culture of L. lactis, the mRNA level of genes was significantly modified. More particularly, a strong reorientation of pyrimidine metabolism was observed when L. lactis was grown in the mixed culture. Keywords: microbial interaction, time course
Project description:The response of L. lactis to the presence of S. cerevisiae was analyzed during the exponential growth phase in fermentors in defined growth conditions. Although no growth kinetic difference was observed between the pure and mixed culture of L. lactis, the mRNA level of genes was significantly modified. More particularly, a strong reorientation of pyrimidine metabolism was observed when L. lactis was grown in the mixed culture. Keywords: microbial interaction, time course A pure culture of L. lactis was conducted in parallel with a co-culture of L. lactis and S. cerevisiae. For the transcriptomic analysis, the mixed culture (test condition, 2.5 hours of culture, Bâ) was compared to the pure culture (reference, 2.5 hours of culture, B) on the same slide at the same time. The mRNA level changes between 2 and 3 hours (A and C samples) flanking B sample (2.5 hours) in the pure culture were also determined on another slide. Total RNA was extracted from these samples and labelled cDNA (Cy3/Cy5) were prepared and hybridized on glass slides exhibiting 2004 amplicons specific of Lactococcus lactis IL1403 genes. 3 independent repetitions were performed.
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. Strains were cultured on skimmed raw milk ultrafiltration (UF) retentate. The UF retentate was pre-incubated overnight at 4 °C, then 45 minutes at 50 °C and homogenized during 1.5 minutes at 24 000 rpm with an ultra-turax (Imlab, France). After addition of rennet (0.3 µl ml-1), 400 g UF retentate was inoculated at 2 106 CFU/g with L. lactis subsp. lactis strains. After incubation for 8 hours at 30 °C, the cheeses were transferred at 12° C until 7 days for ripening simulation. At least three independent cultures of the six strains were performed. Total RNA was extracted from cells grown 24 hours in UF-cheese and radiolabelled cDNA were prepared and hybridized on nylon arrays. 1948 amplicons specific of Lactococcus lactis IL1403 genes were spotted twice on the array. 3 independent repetitions were performed.
Project description:In the present study, we investigated the effect of Lactobacillus lactis on healthspan using Caenorhabditis elegans as a model animal. The healthspan of the adult C. elegans fed the mixture of E. coli OP50 and Lactobacillus lactis NBRC 100913 or NBRC 12007 strains was significantly longer than that of animals fed sole OP50 (control). Transcriptional profiling comparing Lactobacillus lactis- and control-fed animals suggested that genes related to “locomotion” were upregulated by Lactobacillus lactis.
Project description:In the present study, we investigated the effects of feeding Lactococcus lactis using Caenorhabditis elegans as a model animal. The survial of the adult C. elegans fed L. lactis was significantly better than that of unfed animals (control) upon infection with pathogens.
Project description:This SuperSeries is composed of the following subset Series: GSE23987: Transcriptomic profiles of six strains of Lactococcus lactis in ultrafiltration-cheese model GSE23990: Comparative genome hybridization profiles of six strains of Lactococcus lactis Refer to individual Series