High concentration ethanol production from corncob residues by fed-batch strategy

Ethanol production from corncob residues (CCR) pretreated by different methods was studied. The structure features of these CCR were analyzed by Fourier transform-infrared spectrum (FT-IR), X-ray diffraction (XRD), and field emission scanning electron microscope (SEM). Simultaneous saccharification and fermentation (SSF) was performed by adding crude cellulase preparations from Penicillium decumbens JUA10-1 at 30 °C. The results suggested that different pretreatments resulted in different composition and structure of residues; these changes had a significant influence on ethanol productivity and concentration. The fed-batch method was combined with SSF to enhance ethanol concentration further and reduce enzyme dosage. Moreover, the absorption and desorption phenomena of cellobiohydrolase I (CBH I) (70 kDa) were observed to be related to lignin contents in residues. These results demonstrated that despite the application of low enzyme dosage, high concentration ethanol could be produced from pretreated corncobs by combining fed-batch method with SSF.