Modified simultaneous saccharification and co-fermentation of DLC pretreated corn stover for high-titer cellulosic ethanol production without water washing or detoxifying pretreated biomass.

Corn stover (CS) pretreated by DLC (Densifying Lignocellulosic biomass with acidic Chemicals) pretreatment exhibited higher digestibility and much better fermentability compared to traditional pretreatments. Nevertheless, the xylose fermentation, which was a key for lignocellulosic ethanol production, during SHCF (Separate Hydrolysis and Co-Fermentation) was unsatisfactory at high solid loadings. In this study, modified SSCF (Simultaneous Saccharification and Co-Fermentation) was adopted to promote xylose utilization and ethanol yield. SSCF conditions (temperature, inoculation size, nitrogen source addition) were investigated. A novel strategy "Fed-batch of DLC Biomass and Enzyme (FBE)" was developed for SSCF at 28%–35% solid loadings, which showed higher sugar conversion, higher xylose consumption and superior ethanol yield compared to SHCF and traditional SSCF. The highest ethanol titer of 74.6 g/L produced based on DLC pretreatment was achieved during FBE SSCF without water washing or detoxification of DLC-CS. • SSCF was studied on DLCA (sa)-CS without washing or detoxifying pretreated biomass. • A strategy "Fed-batch of DLC Biomass and Enzyme (FBE)" was developed for SSCF. • FBE SSCF greatly improved xylose consumption, sugar conversion and ethanol yield. • The highest ethanol titer of 74.6 g/L based on DLC pretreatment was achieved. [ABSTRACT FROM AUTHOR]