Spent Shiitake mushroom medium was subjected to steam explosion followed by simultaneous saccharification
and fermentation (SSF) using Meicelase and Saccahromyces cerevisiae AM12. Water extraction of
the medium exposed to steam at 20 atm for 5 min enhanced the saccharification rate by about 20%
compared to steam-exploded medium before water extraction and resulted in the production of
23.8 g/l ethanol from a substrate concentration of 100 g/l. This corresponded to 87.6% of the theoretical
ethanol yield, i.e., 15.9 g ethanol was obtained from 100 g of spent Shiitake mushroom medium. Spent
Shiitake mushroom medium subjected to steam explosion and then water extraction appears to be a candidate
for efficient bioconversion to ethanol.