Isolation of Germination Mutants in Saccharomyces cerevisiae

Abstract:

The spores of Saccharomyces cerevisiae firstly were applied for enzyme immobilization as microcapsule. The utilization of the enzyme has been limited due to germination of spores when treated with nutrients，thus finding germination mutant yeast spore has a significant effect on applying of microcapsule. We used EMS as a mutagen for yeast cells and screened by ether and isolated 4 mutants，AN120-m5，AN120-m8，AN120-m10 and AN120-m17. They all can sporulate and grew well except that AN120-m5 was slightly deficient in cell growth. When verifying the germination efficiency of 4 mutants in the liquid medium and on solid medium，4 mutants all exhibited obvious germination defect，however only 1% AN120-m10 spores germinated in the liquid medium，and single spore of AN120-m5 completely cannot germinate on solid medium. Hybrid cells of AN120-m5 cannot be collected because of its defect on solid medium，and other 3 mutant haploid cells crossed with wide type haploid cells after 3 generations，and spores of wild type exhibited a germination eudismic ratio of 2∶2 compared with mutant spores. This suggested that a single gene was mutated in mutant strains will facilitate to find mutated gene in later screening in order to isolate a strain that completely doesn’t germinate.