7.3. Mutagenesis
Industrially important S. cerevisiae is a good producer of ethanol. It shows higher tolerance to ethanol, but it lacks thermotolerance. Therefore, mutation screening for thermotolerance was performed with a proofreading-deficient DNA polymerase or UV irradiation. A S. cerevisiae mutant capable of growing at temperatures up to 40–42°C was selected [78] and [79]. A respiratory mutant of C. glabrata yielded 17.0 g/L of ethanol from 50 g/L of Avicel/microcrystalline cellulose at 42°C under aerobic conditions in the presence of sufficient cellulase [80].