Utilization of dry distiller's grain and solubles as nutrient supplement in the simultaneous saccharification and ethanol fermentation at high solids loading of corn stover.

Dry distiller's grain and solubles (DDGS) is a major by-product of corn-based ethanol production and is usually used as animal feed. Here, it was added to the simultaneous saccharification and ethanol fermentation (SSF) carried out at high solids loading of steam explosion pretreated corn stover using a mutant strain Saccharomyces cerevisiae DQ1. The performance of SSF process with DDGS was comparable to those using the expensive yeast extract supplementation. With 30% (w/w) solids plus the addition of cellulase and 1g DDGS l(-1), the final ethanol reached 55 g l(-1) (7% v/v). The results indicated that the expensive supplement of yeast extract could be replaced by DDGS.