We selected four different genes from the gene library of plyextremotolerant black yeast A. pullulans and cloned them into cells of S. cerevisiae by homologous recombination. As a vector, we used plasmid pBEVY-U which has gene URA3 selection marker. The plasmid was multiplied in two parts with PCR so that they overlapped in the selection marker gene. In the case of successful transformation, fragments assembled within a cell and produced functional selection marker which could be expressed. After the transformation process we tested successfully transformed cells with few different stress factors – KCl, NaCl, LiCl, sorbitol and glycerol. The results showed that the Acu1 P-type ATPase improved growth of transformed cells in high K+ medium, whereas Acu2 ATPase allowed transformed cells to grow on the agar media with drastically reduced K+ content. Nha antiporters successfully improved yeast tolerance to NaCl, which was able to grow on medium containing NaCl at concentrations of 2 mol/L. Hak transporter have improved growth of transformed cells on medium containing up to 25 % glycerol and at high (590 mM) concentrations of LiCl. We have also performed some in silico analyses of protein sequences to gather more data about the chosen proteins.
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