title: Genome comparison and physiological characterization of eight Streptococcus thermophilus strains isolated from Italian dairy products.
abstract: Eight Streptococcus thermophilus strains of dairy origin isolated in Italy were chosen to investigate autochthonous bacterial diversity in this important technological species. In the present study a comparative analysis of all the 17 S. thermophilus genomes publicly available was performed to identify the core and the variable genes, which vary among strains from 196 to 265. Additionally, correlation between the isolation site and the genetic distance was investigated at genomic level. Results highlight that the phylogenetic reconstruction differs from the geographical strain distribution. Moreover, strain M17PTZA496 has a genome of 2.15 Mbp, notably larger than that of the others, determined by lateral gene transfer (including phage-mediated incorporation) and duplication events. Important technological characters, such as growth kinetics, bacteriocin production, acidification kinetics and surface adhesion capability were studied in all the Italian strains. Results indicate a wide range of variability in adhesion properties that significantly clustered strains into four groups. Genomic differences among strains in relation to these characters were identified but a clear correlation between genotype and phenotype was not always found since most of the genomic modifications arise from single nucleotide polymorphisms. This research represents a step forward in the identification of strains-specific functions in Streptococcus thermophilus and it has also the potential to provide valuable information to predict strain specific behaviors in industrial processes.
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), viale dell'Università, 16, 35020 Legnaro, Padova, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Vendramin
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), viale dell'Università, 16, 35020 Legnaro, Padova, Italy; Department of Environmental Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
authors.forename: Laura
authors.initials: L
authors.lastname: Treu
authors.affiliation: Department of Biology, University of Padova, via Ugo Bassi 58/b, 35121 Padova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Campanaro
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), viale dell'Università, 16, 35020 Legnaro, Padova, Italy.
authors.forename: Angiolella
authors.initials: A
authors.lastname: Lombardi
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: viviana.corich@unipd.it.
authors.forename: Viviana
authors.initials: V
authors.lastname: Corich
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), viale dell'Università, 16, 35020 Legnaro, Padova, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Giacomini
mesh_terms: D000818:Animals; D001430:Bacteriocins / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D003611:Dairy Products / Q000382:microbiology*; D014644:Genetic Variation; D016680:Genome, Bacterial; D023281:Genomics; D005838:Genotype; D007558:Italy; D008892:Milk / Q000382:microbiology*; D010641:Phenotype; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D048249:Streptococcus thermophilus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D001430:Bacteriocins; D004269:DNA, Bacterial
keywords: Bacterial biodiversity; Dairy products; Genome comparison; Streptoccocus thermophilus