Abstract:Abstract: The alternative sigma factor Sigma B plays important roles in both virulence and stress tolerance in Listeria monocytogenes. It is now clear that there is a strong link between the virulence potential of Listeria monocytogenes and its ability to tolerate stress. Several studies have identified genes that play important roles in stress tolerance and virulence. For example, genes involved in osmotic stress tolerance, acid and alkaline tolerance, oxidative stress tolerance, extreme temperature tolerance, and bile salt tolerance have all been implicated in the virulence of L. monocytogenes. We reviewed the role of Sigma B in several environmental stress conditions to understand the physical character of this microorganism, to discuss the best preservation conditions of food, and to prevent bacterial infection.