Open AccessComparison of cultural methods for the identification and molecular investigation of yeasts from sourdoughs for Italian sweet baked products
Author(s) -
Foschino Roberto,
Gallina Silvia,
Andrighetto Christian,
Rossetti Lia,
Galli Antonietta
Publication year - 2004
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1016/j.femsyr.2003.12.006
Subject(s) - biology , rapd , yeast , internal transcribed spacer , identification (biology) , genetic diversity , restriction enzyme , genetics , strain (injury) , genomic dna , restriction fragment length polymorphism , dna sequencing , gene , polymerase chain reaction , botany , ribosomal rna , population , demography , anatomy , sociology
Twenty‐five yeast strains isolated from sourdough samples for Panettone, Pandoro and Cornetto brioche manufactured by eight different bakeries in northern Italy were characterised. Classification was performed by the simplified identification method (SIM), Kurtzman and Fell's identification protocol, the API system from bioMérieux (France) and the MicroLog TM system from Biolog (USA). Genetic diversity was investigated by randomly amplified polymorphic DNA fingerprinting and mitochondrial‐DNA restriction enzyme analysis. Sequences of the internal transcribed spacers between 18S and 26S rDNA genes were analysed. Candida humilis was the predominant species (56% of isolates), whereas the remaining strains (44%) were related to the Saccharomyces cerevisiae sensu stricto group. Identification systems based on phenotypic analysis proved to be unreliable to identify yeasts from sourdough. Either RAPD‐PCR or mtDNA restriction analysis showed to be suitable for the identification of species, but could not be used to differentiate among the isolates at the strain level. Sequencing of the ITS region permitted a consistent classification of the sourdough yeasts.