Title
Ethanol production from unpretreated waste medium of shiitake mushroom (Lentinula edodes) by semi-simultaneous saccharification and fermentation under high substrate concentration conditions
Authors
RYO HIYAMA AKIRA HARADA GISUSI SEIKI and KEN ORIHASHI

Received November 18, 2014
Published Volume 50 Issue 7-8 July-August
Keywords waste mushroom medium, Lentinula edodes, willow, bioethanol production, simultaneous saccharification and fermentation

Abstract
Waste mushroom medium (WM) from cultivation of shiitake mushroom (Lentinula edodes),using meals of willow species Salix sachalinensis (WMS) or Salix pet-susu (WMP), was air-dried, roughly pulverized, and used to produce ethanol by semi-simultaneous saccharification and fermentation (SSSF) with commercial cellulase (Meicelase) and dry yeast (Ethanol Red). Glucan content of WMS and WMP was 31.5% and 29.6%, respectively. SSSF of WMS at a final concentration of 72% (w/v), introduced over 4 substrate additions, with 5 FPU Meicelase/g of final substrate processed for 232 h, produced an ethanol concentration of 56 g/L and an ethanol yield of 46%. No significant difference was detected in the yield of glucose and ethanol between SSSF performed using air-dried and pulverized WMS (<10 mm) and that using raw and roughly broken WMS (>40 mm). These results indicate that shiitake WM can be used for SSSF without pretreatment and pulverization.