A new transformation system of Saccharomyces cerevisiae with blasticidin Sdeaminase gene

A new method for transformation of Saccharomyces cerevisiae that allows sel ection was developed. As the frequency of spontaneous blasticidin S resista nt mutants from diploid type yeast strain (X-2180AB) was 5.2x10(-6), which was a thousandfold less than that from haploid type yeast strain (X-2180B), it was considered that the mechanism of spontaneous blasticidin S resistan t mutations was related to recessive gene. Industrial yeasts, which were di ploid, were transformed with blasticidin S deaminase gene from Aspergillus terreus to blasticidin S resistance. Expression of blasticidin S deaminase gene allowed selection of transformants from industrial yeasts.