Narrow Results

To develop biofuel production from waste lignocellulosic biomass materials the rice straw was selected one of renewable material and the degradation condition about pretreatment and enzymatic hydrolysis to obtain effectively fermentable sugars was investigated. Rice straw was pretreated by five kinds of methods and then the components ratio of rice straw was examined. First, the steam explosion was selected based on the degradability and the requirement energy. In addition, the best suitable combination of two cellulases to effective and economical hydrolyze was determined from the degradability of these pretreated rice straws. In the simultaneous saccharification and fermentation of the steam explosion rice straw by combining cellulase cocktail and a novel fermenting fungus, 13.2 g/L ethanol was able to product for 96 h.

Waste Shiitake (Lentinula edodes) mushroom medium, a lignocellulosic aglicultural residue, was evaluated as a fermentable substrate. 87% of the fermentable sugars remained in the waste mushroom medium. The sugar yield of the waste mushroom medium (46.3%) was higher than that of raw mushroom medium (20.3%) after 48 h of enzymatic saccharification by Meicelase because L. edodes changed wood structure. These results indicated that the waste mushroom medium is a suitable substrate for fermentation. Next, the efficient ethanol production using steam explosion pretreatment was studied. After 30 h of simultaneous saccharification and fermentation (SSF) using Meicelase and Saccharomyces cerevisiae AM12, 20.0 g/L ethanol was produced from 100 g/L water-insoluble residue of the waste mushroom medium treated at a steam pressure of 20 atm and a steaming time of 5 min. This corresponded to an ethanol yield of 77.0% of the theoretical, i.e. 14.7 g of ethanol obtained from 100 g of waste mushroom medium.