INTRODUCTION OF MITOCHONDRIA INTO RESPIRATORY-DEFICIENT MUTANT OF YEAST AND IMPROVEMENT OF THERMOSTABILITY

Mitochondria of Saccharomyces cerevisiae TSS, with activity related to thermostability, was introduced into a respiratory-deficient mutant ( rho(-)) of F-1 by protoplast fusion. The mitochondria-introduced strai ns which were recovered as respiratory-sufficient strain (rho+) were o btained at a frequency of 1 x 10(-6). The strains acquired the mitocho ndrial thermostability of S. cerevisiae TS8. Some of the strains were superior to F-1 in growth and fermentation ability at high temperature s.