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:Gene content in various Enterococcus faecalis strains compared to E. faecalis V583. Strains have been compared to the V583 strain by comparative genomic hybridization using genome-wide PCR-based microarrays representing the V583 genome. Genes have been deemed "present" or "divergent" in the various strains.
Project description:A group of gram positive bacteria that share the characteristic of fermenting hexose sugars to lactic acid are generally referred to as lactic acid bacteria (LAB). Enterococcus faecalis is one of the widely studied LABs due to a multiutude of reasons. On the one hand, it plays an important role in dairy industry, being for example a starter in cheese cultures. On the other hand, it accounts for a large part of the infections caused by the LABs in hospital environments. During the past few years, it developed resistance against most of the major antibiotics. Here, in an attempt to study its adaptive metabolism, a glutamine synthetase mutant (∆glnA) of E. faecalis was subjected to pH shift and the results from the integrative analysis of its metabolic network were compared to those of the wild type. The proteome data generated in this study were used to constrain the genome-scale metabolic network at two pH level, aiming to reduce the solution space and improve the accuracy of model simulation. This data particularly helped to come up with a new design for the amino acid transport system in the genome-scale model, resulting in an accurate reproduction of the metabolic behaviour of E. faecalis.