title: Comparison of molecular and metabolomic methods as characterization tools of Debaryomyces hansenii cheese isolates.
abstract: Debaryomyces hansenii is one of the yeast species most frequently isolated from cheese and salty foods, however little is known about the phenotypic and molecular variability of its strains. In order to explore the possibilities of a large study on its biodiversity, some D. hansenii strains were selectively isolated from pecorino cheese sampled in ten different Italian regions. All isolates were identified as D. hansenii on the basis of conventional and molecular taxonomic analysis. The D1/D2 domain sequences of the 26S-rDNA did not show any variation, confirming the extreme homogeneity of this species. PCR-duplex-RAPD banding patterns analyzed with PCoA showed interesting clustering related to the geographic areas of isolation, although some overlapping between strains derived from different districts could be observed. A FTIR (Fourier Transform Infrared Spectroscopy) metabolomic fingerprint produced groupings weakly related to those observed with RAPD and less associated with the isolation locales. The discriminatory power of metabolomic fingerprint was able to discriminate strains otherwise considered identical. This preliminary study showed that, in spite of the homogeneity at the 26S-rDNA level, the D. hansenii strains exhibit high molecular and metabolomic variability somehow linked to the places of isolation. Further studies will be necessary to better investigate on the link between terroir and strain variability, as well as on the relation between genotypic and metabolomic fingerprints.
authors.affiliation: Department of Applied Biology-Microbiology, University of Perugia, Borgo 20 Giugno, 74, I-06121 Perugia, Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Del Bove
authors.forename: Monia
authors.initials: M
authors.lastname: Lattanzi
authors.forename: Paolo
authors.initials: P
authors.lastname: Rellini
authors.forename: Cristina
authors.initials: C
authors.lastname: Pelliccia
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fatichenti
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Cardinali
mesh_terms: D002611:Cheese / Q000382:microbiology*; D004271:DNA, Fungal / Q000032:analysis*; D004275:DNA, Ribosomal / Q000032:analysis; D055165:Debaryomyces / Q000145:classification* / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D016533:Mycological Typing Techniques; D010641:Phenotype; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique; D012680:Sensitivity and Specificity; D013045:Species Specificity; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal