Use of conventional taxonomy, electrophoretic karyotyping and DNA-DNA hybridization for the classification of fermentative apiculate yeasts

A taxonomic study was conducted that considered strains of the genera Hanse niaspora/Kloeckera held in the Industrial Yeasts collection (DBVPG) of the Dipartimento di Biologia Vegetale of the Universita di Perugia, Italy. Stan dard phenotypic as well as molecular criteria were considered in a effort t o revisit the classification of these strains, some of which have been in t he collection far about 50 years. Results of salient physiological tests sh owed that some of the DBVPG and type strains could not be identified by cur rent taxonomic keys. Electrophoretic karyotypes were identical for some spe cies, with the type strains of the seven accepted species showing only five distinct chromosomal patterns. DNA-DNA hybridization analyses, using a non radioactive dot-blot technique, allowed for the distinction of taxa. The ta xonomic implications of these results are discussed.