Tolérance et réponse adaptative au stress acide chez Lactobacillus delbrueckii ssp. bulgaricus

Tolerance and adaptative acid stress response of Lactobacillus delbrueckii ssp. bulgaricus. Using several approaches, we studied the acid stress response of different strains of Lactobacillus bulgaricus. We showed that after an acid shock, the cell survival varied considerably between strains and that all the studied strains were able to develop an acid adaptive response. For one of these strains, we characterized, using two-dimensional electrophoresis, the modifications in the protein pattern induced by acid adaptation. Out of the 50 proteins up-regulated under the adaptive conditions, 21 were identified after N-terminal sequencing. They belong to different functional categories including stress response and general metabolism. To allow a larger genetic exploration of L. bulgaricus, the genome of the type strain ATCC 11842 was sequenced in collaboration with the Genoscope. All together, these genomic and post-genomic data should lead to a better understanding of L. bulgaricus physiology and its environmental adaptability. Lactobacillus bulgaricus / acid stress / proteome / genome sequence