Culture independent approach for the evaluation of presence and activity of microorganisms in food

The relation between microorganisms and food excited much interest since the existence of bacteria has been observed. So far, many efforts have been put in trying to investigate this association, especially through traditional, culture-based methods. However, further the knowledge of structure and dynamics of the whole microbial community, would promote better understanding of how food ecosystems are influenced by microbial growth and metabolism. For instance, greater control over microflora composition would make it possible to better select for specific organoleptic properties, to prevent quality defects or spoilage and to guarantee food safety. Trying to shed light on what traditional culture-dependent methods left hanging, aim of this PhD thesis, was to find new ways to study microorganisms in food. Fluorescent staining, FISH (fluorescence in situ hybridization) and LH-PCR have been used to gain a deeper knowledge of microbial composition and dynamics of different food matrices, such as artisanal beer, Parmigiano Reggiano natural whey starter and Parmigiano Reggiano cheese.