[...]... Domenico Carminati Abstract The dynamics of growth, survival, and biochemical activity of microorganisms in fermented foods are the result of stress reactions in response to the changing of the physical and chemical conditions into the food micro-environment, the ability to colonize the food matrix and to grow into a spatial heterogeneity, and the in situ cell-to-cell ecological interactions which often happen... revolutionized microbial ecology, resulting in the development of several techniques of microbial community fingerprinting Although most of these methods are generally based on the amplification of only the variable regions or the totality of the 16S rRNA genes, amplified fragments can also derive from total RNA extracted from food and amplified by reverse transcriptase-PCR (RT-PCR) 1 Molecular Techniques in. .. exponentially growing cells (de Vries, et al 2004) A fundamental obstacle to the application of FISH in food is that the fragile structure of a fat-rich matrix (e.g cheese) may impair the 1 Molecular Techniques in Food Fermentation 11 maintaining of the spatial in situ distribution of microbial populations in foods Recently, Ercolini, et al (2003b) applied to Stilton cheese an embedding procedure using a plastic... methods, based on molecular techniques, which are powerful to fingerprint specific DNA patterns that are characteristics for a single strain, form the mainstay of strain typing of LAB The introduction of molecular biology techniques has yielded a variety of DNA-based typing methods, which can even discriminate between isolates of a given species Depending on the technical aspects, genetic typing methods... fields of food microbiology: the identification of microorganisms isolated from food, the assessment of the impact of probiotic bacteria on the native human gastrointestinal microflora, the evaluation of microbial diversity during food fermentation (e.g naturally fermented Sausages, 1 Molecular Techniques in Food Fermentation 7 dairy and cereal products, wine, rice vinegar), and the assessment of the. .. active in the community (Giraffa 2004) The exciting review of Forney, et al (2004) underlines pro and contra of molecular methodologies for studying microbial ecology, and suggests that our knowledge of microbial diversity is still very limited At the present state of our knowledge, authors define microbial ecology very suggestively as The land of the one-eyed king.” 24 G Giraffa and D Carminati References... Summary of the Most Widely Used Culture-independent Techniques and Their Applications to Microbial Ecology Applications to Microbial Taxonomic Resolution Ecology PCR-based Methods - PCR-DGGE/PCR-TGGE Community members (genus/ Community fingerprinting; species level) population dynamics - SSCP Community members (genus/ Mutation analysis; community species level) fingerprinting; population dynamics - T-RFLP... that most of the reported studies have focused on the analysis of end products DGGE and other techniques have, however, been more successfully applied in polyphasic studies to monitor the microbial dynamics of food ecosystems (Ercolini 2004; Ercolini, et al 2004) By combining different methods (e.g PCR-DGGE, cloning and sequencing of rRNA gene amplicons, and classical cultivation techniques) in a “polyphasic... essentially consist of the amplification of the genes encoding the 16S rRNA from the matrix containing different bacterial populations, followed by the separation of the DNA fragments Separation is based on the decreased electrophoretic mobility of PCR amplified, partially melted, double-stranded DNA molecules in polyacrylamide gels containing a linear gradient of DNA denaturants (PCR-DGGE) or a linear temperature... Molecular Techniques in the Microbial Ecology of Fermented Foods © Springer 2008 2 1 G Giraffa and D Carminati Introduction Within the fermentation industry, microorganisms are used for the production of specific metabolites such as acids, alcohols, enzymes, antibiotics and carbohydrates Major fermentation microbes include lactic acid bacteria (LAB), molds and yeasts In particular, LAB are the major microflora . Fermented Foods, Luca Cocolin and Danilo Ercolini (Eds.) (2008) Luca Cocolin • Danilo Ercolini Editors Molecular Techniques in the Microbial Ecology of Fermented Foods Luca Cocolin Dipartimento. on the microbiology of fermented foods, but this is the first to approach the subject from a novel point of view, reporting the new insights drawn in the microbial ecology of fermented foods. book takes into consideration both well-known fermented foods and non-European foods and describes the latest findings in the microbial ecology as determined by the application of molecular