said:

The following strategy is based on isolation of natural mutants for food sources or drugs. We tried something like this with P. falciparum, which is not yeast.
you make plates with your source of Carbon and streak your yeast on it. It would take some time, but eventually you would see colonies coming up.
If they are real mutants, they would grow faster if you grow them on similar plates.
Specific protocols are available in papers.