Multinuclear Yeast Magnusiomyces (Dipodascus, Endomyces) magnusii is a Promising Isobutanol Producer

Higher alcohol isobutanol is a promising liquid fuel. During alcoholic fermentation, Saccharomyces cerevisiae produces only trace amounts of isobutanol. Screening the collection of nonconventional yeasts show that Magnusiomyces magnusii accumulates 440 mg of isobutanol per L in rich YPD medium. Here, the transformation protocol for M. magnusii is adapted based on the use of the dominant markers conferring resistance to nourseothricin or zeocin; the strong constitutive promoter TEF1 is cloned and a reporter system based on LAC4 gene from Kluyveromyces lactis coding for β‐galactosidase is constructed. In order to increase isobutanol production in M. magnusii, the heterologous gene ILV2 from S. cerevisiae is expressed in M. magnusii under control of the TEF1 promoter. The best stabilized transformants produce 620 mg of isobutanol per L in YPD medium and 760 mg L−1 in the medium with 2‐oxoisovalerate. This suggests that M. magnusii is a promising organism for further development of a robust isobutanol producer. The higher alcohol isobutanol is a promising liquid fuel. Screening the collection of nonconventional yeasts showed that Magnusiomyces magnusii accumulates 440 mg of isobutanol per L, while Saccharomyces cerevisiae produces only trace amounts of isobutanol. This study is the first report on the development of the basic methods of molecular research for this species for improvement of isobutanol production.