mtDNA restriction analysis has been carried out with 45 different commercia
l Saccharomyces wine yeast strains. The analysis with Hinf I provided uniqu
e profiles for 17 of the 45 strains and can therefore be considered as indi
vidual strains. Nevertheless, among the remaining 28 strains, only eight mt
DNA restriction patterns appeared. These strains were subjected to electrop
horetic karyotyping and PCR amplification of delta sequences. We concluded
that the maximum discriminatory power was obtained when the results of the
three techniques were combined, giving 13 different composite patterns for
the 28 strains under study. The results showed evidence of mistakes during
production or fraudulent practices by yeast producers, since only 30 indivi
dual strains have been identified among the 45 Saccharomyces wine yeast str
ains commercialised by different companies. Additionally, commercial starte
rs of Saccharomyces uvarum and Saccharomyces bayanus have been re-identifie
d as Saccharomyces cerevisiae. (C) 2001 Elsevier Science B.V. All rights re
served.