Classical and molecular analyses to characterize commercial dry yeasts used in wine fermentations.
OBJECTIVE
The aim of the work was to apply PCR-temperature gradient gel electrophoresis (PCR-TGGE) and restriction enzyme analysis (RE) assays to identify commercially available starters of Saccharomyces cerevisiae sensu stricto complex.


RESULTS
To characterize an analysed pool of 62 active dry yeasts of different brands used in wine fermentation practices, classical microbiological tests were also performed as well as evaluation of contamination with lactic acid bacteria and non-Saccharomyces yeasts. PCR-TGGE and RE were used in order to provide fast and reliable methods to identify and differentiate enological yeasts. Proposed molecular methods enabled to identify particular strains within 36 h after colony isolation and directly from dry yeast suspension.


CONCLUSIONS
The methods are highly recommended to obtain reliable results on yeast strain differentiation in a significantly shorter time if compared to classical fermentation tests.


CONCLUSIONS
The obtaining of yeast strain differentiation in a short time and without plating is a good tool for a rapid discrimination among enological strains used as starters in enological practices.
Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, Udine, Italy. marisa.manzano@uniud.it
M
M
Manzano
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D
Medrala
C
C
Giusto
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I
Bartolomeoli
R
R
Urso
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G
Comi
D015169:Colony Count, Microbial / Q000379:methods; D003470:Culture Media; D004271:DNA, Fungal / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005285:Fermentation; D005690:Galactose / Q000378:metabolism; D007778:Lactobacillus / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping / Q000379:methods; D012440:Saccharomyces / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification*; D014920:Wine / Q000382:microbiology*
D003470:Culture Media; D004271:DNA, Fungal; D005690:Galactose