Adaptation of staphylococcus xylosus to pork meat batter during the fermentation step

Staphylococcus xylosus is used as starter culture for sausage fermentation for a long time but the molecular mechanisms for its adaptation in meat remained unknown. A global transcriptomic approach was carried out to determine these molecular mechanisms. S. xylosus modulated the expression of 38 to 48 % of the total genes during its growth and survival in the meat model. The expression of many genes encoding enzymes involved in glucose and lactate catabolism up to the respiratory chain and in cofactors synthesis necessary to their activities was up regulated. In parallel, genes encoding transport of peptides and peptidases that could furnish amino acids were up expressed and thus concomitantly a lot of genes involved in amino acids synthesis were down regulated. Finally S. xylosus responded to salt added in the meat model by over expressing genes involved in transport and synthesis of osmoprotectants, Na+ and H+ extrusion and in production of energy through the F0F1-ATPase