title: Microbial analyses of traditional Italian salami reveal microorganisms transfer from the natural casing to the meat matrix.
abstract: In this study the bacterial biodiversity, during the maturation process of traditional sausages (Salame Mantovano), produced with two different kinds of casing (hog middle or "Crespone" and hog bung or "Gentile"), was investigated by means of culture-dependent and -independent methods. In order to assess the natural variability linked to the type of casing used in production, the ingredients, as well as ripening conditions, were identical in both productions. The aim of the study was to understand the contribution of casing microflora during sausage ripening by identifying the dominant species and strains. The bacterial ecology of casings and salami at different ripening stages, as determined by plating, revealed higher staphylococci and enterococci counts for Gentile casing and for the entire ripening period of the salami studied. After molecular identification of 219 Lactobacilli and 225 cocci gram positive catalase positive (GPCP) isolates, the species most frequently isolated were Lactobacillus sakei, Lactobacillus curvatus, Staphylococcus xylosus, and Staphylococcus saprophyticus. Some L. sakei and S. saprophyticus strains, coming from casing, were also found in the salami at different times of ripening. A richer biodiversity was only detected at the beginning of maturation. We also report the first detection, by PCR-DGGE method, of Arcobacter marinus and Brochothrix thermosphacta species in casings and Kokuria salsicia in fresh sausage. Results suggesting that casing can be an important source of bacteria during natural fermentation when starter cultures are not used.
authors.affiliation: Centro Ricerche Biotecnologiche, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Milano 24, 26100 Cremona, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Pisacane
authors.affiliation: Centro Ricerche Biotecnologiche, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Milano 24, 26100 Cremona, Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Callegari
authors.affiliation: Istituto di Microbiologia, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Puglisi
authors.affiliation: Istituto di Microbiologia, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Dallolio
authors.affiliation: Centro Ricerche Biotecnologiche, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Milano 24, 26100 Cremona, Italy. Electronic address: annalisa.rebecchi@unicatt.it.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Rebecchi
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D018407:Bacterial Physiological Phenomena; D044822:Biodiversity; D005285:Fermentation; D005516:Food Microbiology; D008461:Meat Products / Q000382:microbiology*; D016133:Polymerase Chain Reaction
keywords: Fermented sausages; Lactobacillus; Microbial ecology; Molecular methods; Natural casing; Staphylococcus