title: Microbial evolution of traditional mountain cheese and characterization of early fermentation cocci for selection of autochtonous dairy starter strains.
abstract: The microbial population of Traditional Mountain (TM) cheese was investigated and characterized for the selection of cocci suitable for developing new starter cultures. Samples of milk, curd and cheese at different ripening times were enumerated in selective culture media and 640 colonies were isolated from curd and cheese after 24 h of ripening. The Lactic Acid Bacteria (LAB) isolated from M17 were clustered into 231 biotypes by RAPD-PCR analysis and identified as Lactococcus lactis, Streptococcus thermophilus and Enterococcus faecalis. Forty percent of enterococci showed the in vitro ability to inhibit raw milk resident coliforms, but they were excluded as possible starters due to the presence of associated risk factors. All lactococci and streptococci were tested for their technological properties; 4 Lc. lactis subsp. lactis and 2 Sc. thermophilus which were fast acidifiers and did not produce unpleasant flavours were subjected to the freeze-drying stability test. Lc. lactis subsp. lactis biotype 68 and Sc. thermophilus biotype 93 showed the best technological properties and may be appropriate for cheese production. This work gave evidence of the high biodiversity of TM-cheese autochthonous biotypes which could be used as starter cultures for the improvement of TM-cheese technology.
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Carafa
authors.affiliation: Agricultural, Food and Enviromental Sciences-D3A, Università Politecnica delle Marche, 60131 Ancona, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Clementi
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy.
authors.forename: Kieran
authors.initials: K
authors.lastname: Tuohy
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy. Electronic address: elena.franciosi@fmach.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Franciosi
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D044822:Biodiversity; D005075:Biological Evolution; D002417:Cattle; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D015169:Colony Count, Microbial; D005285:Fermentation; D007777:Lactobacillaceae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008892:Milk / Q000382:microbiology*; D019105:Random Amplified Polymorphic DNA Technique; D013291:Streptococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
keywords: Flavours notes production; Lactic acid bacteria; Mountain cheese; RAPD-PCR; Starter selection