Complex sentence: Typical microorganisms used to make alcohol, such as yeasts of the genus "Saccharomyces", cannot ferment these starches, and so "koji" mold such as "Aspergillus oryzae" is used to break down the starches into simpler sugars.
Split into simpler sentences: Typical microorganisms used to make alcohol, such as yeasts of the genus "Saccharomyces", cannot ferment these starches. Therefore, "koji" mold such as "Aspergillus oryzae" is used to first break down the starches into simpler sugars.