Development of a low-cost fermentation medium for ethanol production from biomass.

Nutrient cost is an important aspect in the fermentation of biomass to ethanol. With a goal of developing a cost-effective fermentation medium, several industrially available nutrient sources were evaluated for their effectiveness in the simultaneous saccharification and fermentation of pretreated poplar with Saccharomyces cerevisiae D5A. These studies showed that a low-cost medium containing 0.3% corn steep liquor and 2.5 mM MgSO4 7H2O was similar in performance to a nutrient-rich medium. Besides its low cost, this alternative medium consists of components that are available on a commercial scale, thereby making it industrially relevant.