Direct Utilization of Non-pretreated Hydrolytic Liquid of Dried Distiller’s Grains with Solubles for Bio-Ethanol by Rhizopus arrhizus RH 7-13-9#

Bio-ethanol, as an environment friendly and renewable fuel, has gained increasing worldwide attention and can be produced through the fermentation of the carbohydrates or sugar(s) fraction of biomass materials. Here, dried distiller’s grains with solubles (DDGS), a waste in production of bio-ethanol, were applied to prepare acid-hydrolytic liquid and it was directly used as seed culture and fermentation medium without pretreatment. Rhizopus arrhizus RH 7-13-9# cultured in non-pretreated acid-hydrolytic liquid with pH 4.7 for 30 h could utilize the concentrated hydrolytic liquid as well as the hydrolytic liquid mixed with glucose. A high yield of bio-ethanol was obtained. It was proven that common used medium could be replaced by non-pretreated acid-hydrolytic liquid to some extent. The pretreated process of acid-hydrolytic liquid was avoided that decreased feed stock cost and was significant for the utilization of acid-hydrolytic liquid from lignocellulose materials.