A high-frequency transformation system for the yeast Kluyveromyces lactis

Abstract

This communication describes conditions for Kluyveromyces lactis protoplast regeneration and transformation and shows that a high frequency of transformation can be obtained with recombinant plasmids containing one of a series of K. lactis DNA fragments that presumably carry autonomously replicating sequences (called KARS). The vector YRp7, which contains a Saccharomyces cerevisiae autonomously replicating sequence (ARS), only led to integrative transformation of K. lactis indicating substantial differences in specificity between the DNA replication mechanisms of both yeast species. It is further shown that 2-μm DNA derived vectors giving high frequency transformation in S. cerevisiae can transform K. lactis only with low frequency. © 1982 Springer-Verlag.