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: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: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: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
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:Transcriptome profiling of a L. lactis strain lacking the MDR transporter genes lmrCD and the same strain adapted to cholate was performed. As compared to the parental strain, the cholate-adapted strain showed 124 genes that were significantly differentially expressed more than 1.8-fold . These genes could be grouped into four major functional classes: i.e., genes involved in (i) cell envelope biogenesis; (ii) stress response and molecular chaperones; (iii) general metabolism and house-keeping function; and (iv) the chromosomally embedded sex-factor. Keywords: Mutant versus wild type comparison, stress response, cholate 1. WT1 L. lactis Î?lmrCD (labeled with Cy3) 2. WT2 L. lactis Î?lmrCD (labeled with Cy5) 3. WT4 L. lactis Î?lmrCD (labeled with Cy3) 4. WT5 L. lactis Î?lmrCD (labeled with Cy5) 5. M1 L. lactis Î?lmrCD(R) (labeled with Cy5) 6. M2 L. lactis Î?lmrCD(R)(labeled with Cy3) 7. M4 L. lactis Î?lmrCD(R) (labeled with Cy5) 8. M5 L. lactis Î?lmrCD(R) (labeled with Cy3) Hybridization schema: 1+5 (Slide 176631) 3+7 (Slide 176632) 2+8 (Slide 176633) 4+6 (Slide 176634)
Project description:Gene expression in Lactococcus lactis MG1363 was compared to that of L. lactis MG1363 â??guaA in rich GM17 medium. One condition design comparison of two strains
Project description:Comparison of L. lactis NZ9000 ?lmrR versus L. lactis NZ9000 wild type Keywords: Transcription profiling Comparison between strain lacking transcriptional regulator LmrR of major Lactococcal mdr transporter LmrCD, and wild type parental strain.