Peculiarità diSaccharomyces cerevisiaee quantificazione tramite real-time PCR delle specie microbiche panarie

The sourdough microflora consists of lactic acid bacteria, responsible for acidification and weak proteolysis, and yeasts that mainly carry out the leavening of the dough. Metabolic activities of these microorganisms also affect the sensorial characteristics and prolong the shelf life of the products. Interactions between the two biota generally implicate use of carbohydrates and amino acids and the production of CO2. Is important to understand these interactions to make stable sourdoughs. Most typical Sardinian bread are produced from Triticum durum wheat flour instead of the more common Triticum aestivum. Once mixed with water, the flour is allowed to be spontaneously fermented by an autoctonous microflora, composed by bacteria and yeasts. The aims of this work were to characterize natural yeast species present in Sardinian sourdoughs and to develop and test a molecular method able to monitor the presence of inoculated yeast and bacterial strains in sourdoughs. During doughs conservation (freezing) and reactivation, samples were collected at different timepoints. From these samples total DNA was extracted and analyzed by means of Real Time PCR with primers specific for yeast and bacterial species.