Abstract: Steam explosion was attempted as a pretreatment for the efficient conversion of soy sauce residue into ethanol. The Simultaneous Saccharification and Fermentation (SSF) of steam-exploded soy sauce residue at a steam pressure of 10 atm and a steaming time of 5 min was carried out by using Meicelase and halotolerant Mucor indicus ATCC24905 and gave a maximum ethanol yield, i.e., 0.057 g-ethanol g-1 dry soy sauce residue, at a substrate concentration of 100 g L-1. This value corresponds to 1.9 times higher than that of untreated soy sauce residue, i.e., 0.030 g-ethanol g-1 dry soy sauce residue. At 200 g L-1 of steam-exploded soy sauce residue, though the ethanol yield was 0.052 g-ethanol g-1 dry soy sauce residue, the maximum ethanol productivity, i.e., 0.43 g-ethanol/L/h was obtained. Furthermore, the same ethanol yield and ethanol productivity were obtained at a substrate concentration of 100 g L-1 even if using the steam-exploded soy sauce residue without nutrient medium ingredients such as nitrogen sources and mineral salts.
Chikako Asada, Yui Kondo, Chizuru Sasaki and Yoshitoshi Nakamura, 2010. Bioconversion of Soy Sauce Residue Treated with Steam Explosion into Ethanol by Meicelase and Mucor indicus. Journal of Food Technology, 8: 187-190.