Used in laundry detergents, medicines, and biofuels, certain alcohols known as long-chain fatty alcohols, with 12 to 18 carbon atoms in the backbone, are desirable products. These compounds can be made by a yeast called Saccharomyces cerevisiae. However, yields have remained low, slowing the adoption of microbes as producers of fatty alcohols. Through genetic engineering of S. cerevisiae, scientists improved the concentration and yield of fatty alcohol products from 2 percent to up to 20 percent of the maximum theoretical yield.