ADAPTATION AND RESISTANCE TO EXOGENOUS SULPHITE IN BRETTANOMYCES BRUXELLENSIS

摘要

Several works proved that a high biodiversity is present in B. bruxellensis species both from the genetic and physiological point of view. This polymorphism was also observed in this work where sensitive, low, medium and high SO_2 resistant strains were recognised. Actually, some strains of B. bruxellensis have an innate resistance to SO_2, whereas others can adapt their growth to high levels of sulphur dioxide. This adaptation could be linked to few cells inside a same population that have developed, during yeast evolution, alternative mechanisms or different gene regulations to tolerate strong stress. Among the mechanisms that are involved in the protection to sulphite, some amino acids, in particular proline, could have an important role modulating the SO_2 tolerance. Our preliminary results suggest that intracellular proline could reduce the SO_2 stress. In literature it is reported that proline has a stress-protecting activity on yeasts; it should work as a membrane stabilizer by preventing protein denaturation (Takagi, 2008).