title: Characterisation of Lactobacillus helveticus strains producing antihypertensive peptides by RAPD and inverse-PCR of IS elements.
abstract: Lactobacillus helveticus is used for the manufacture of cheeses and milk-based products. Although it is not considered a probiotic microorganism, some strains demonstrated beneficial effects through the production of antihypertensive peptides from the hydrolysis of casein during milk fermentation. Strain-specificity of bioactive peptide production by L. helveticus makes the availability of reliable typing methods essential for both legal and good manufacturing processes. Accordingly, RAPD and inverse-PCR of five insertion sequence elements were comparatively evaluated for the molecular characterisation of four L. helveticus dairy cultures producing antihypertensive peptides and fourteen reference strains. Calculation of discriminatory indices and cluster analysis of the DNA fingerprints confirmed the suitability of both approaches for acceptable strain differentiation. Although RAPD was more discriminating, for a few test strains a neat discrimination was only achieved through multiplex inverse-PCR, thus suggesting the suitability of a combined analytical approach for a finer strain discrimination.
authors.affiliation: Sezione di Microbiologia Alimentare, Ambientale ed Industriale, Dipartimento di Scienze Alimentari, Agro-Ingegneristiche, Fisiche, Economico-Agrarie e del Territorio (SAIFET), Università Politecnica delle Marche, via Brecce Bianche, Ancona, Italy. l.aquilanti@univpm.it
authors.forename: L
authors.initials: L
authors.lastname: Aquilanti
authors.forename: A
authors.initials: A
authors.lastname: Carbini
authors.forename: R
authors.initials: R
authors.lastname: Strappati
authors.forename: S
authors.initials: S
authors.lastname: Santarelli
authors.forename: G
authors.initials: G
authors.lastname: Silvestri
authors.forename: C
authors.initials: C
authors.lastname: Garofalo
authors.forename: F
authors.initials: F
authors.lastname: Clementi
mesh_terms: D000959:Antihypertensive Agents / Q000378:metabolism*; D004251:DNA Transposable Elements; D052198:Lactobacillus helveticus / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods*; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods*
chemical_list: D000959:Antihypertensive Agents; D004251:DNA Transposable Elements; D010455:Peptides