Differentiation of dairy yeast Kluyveromyces lactis var. lactis and its closest wild relatives from European population 'krassilnikovii'.
Gennadi I. Naumov, Nataliya N. Sukhotina, Elena S. Naumova
Lab. of yeast genetics, GosNIIgenetika, I-Dorozhnyi, 1, Moscow, 117545, Russia
Biological species Kluyveromyces lactis has a complex structure and consist of geographical and ecological populations: European ('krassilnikovii'), North American (var. drosophilarum, 'phaseolosporus', 'aquatic', 'pseudovanudenii', 'new'), Far East Asian ('oriental'), South African ('vanudenii') and dairy (var. lactis ) (Naumova et al., 2004). Thirty-seven Kluyveromyces strains of different origin have been studied by molecular-genetic methods. We found molecular markers, allowing the differentiation of dairy yeast Kl. lactis var. lactis and its genetically closest wild lactose-negative relatives from European population 'krassilnikovii'. Restriction analysis of the IGS2 rDNA region revealed two different Alu I-profiles, corresponding to Kl. lactis var. lactis and population 'krassilnikovii'. Based on the Alu I-restriction analysis of this region it is also possible to differentiate the physiologically similar species Kl. marxianus and Kl. lactis. Origin of clinical Kl. lactis var. lactis isolates is discussed.