title: A polyphasic approach to highlight genotypic and phenotypic diversities of Lactobacillus helveticus strains isolated from dairy starter cultures and cheeses.
abstract: In the present work, 67 strains of Lactobacillus helveticus isolated from whey starter cultures and cheeses were identified and grouped by genotypic and phenotypic methods. Strains were identified by sugar fermentation pattern, by cell-wall protein profile, and by probe hybridisation. Phenotypic diversity was evaluated by a chemometric model taking into account biochemical characteristics (i.e. acidifying and peptidase activities) of technological interest. Genotypic diversity was evidenced by RAPD-PCR, which provided stran-specific patterns and revealed the occurrence of different strains. The RAPD-PCR profiles were clustered according to their similarities: the groups obtained, together with the cell-wall protein profiling and the chemometric information, could be sometimes correlated with the type of cheese and/or dairy niches used as sources of strains. A computerised analysis of genotypic and phenotypic information could be successfully applied for rapid and reliable differentiation and characterisation of Lb. helveticus isolates occurring in different dairy products.
authors.affiliation: Veneto Agricoltura, Istituto per la Qualità e le Tecnologie Agroalimentari, Thiene (VI), Italy. angiolella.lombardi@venetoagricoltura.org
authors.forename: Angiolella
authors.initials: A
authors.lastname: Lombardi
authors.forename: Luciana Dal
authors.initials: LD
authors.lastname: Maistro
authors.forename: Paola
authors.initials: P
authors.lastname: De Dea
authors.forename: Monica
authors.initials: M
authors.lastname: Gatti
authors.forename: Giorgio
authors.initials: G
authors.lastname: Giraffa
authors.forename: Erasmo
authors.initials: E
authors.lastname: Neviani
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D015373:Bacterial Typing Techniques / Q000379:methods; D050260:Carbohydrate Metabolism; D002611:Cheese / Q000382:microbiology*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis*; D003611:Dairy Products / Q000382:microbiology*; D005285:Fermentation; D014644:Genetic Variation; D005838:Genotype; D007778:Lactobacillus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D010641:Phenotype; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial