초록
<P><B>Abstract</B></P> <P>Four combined strategies of irradiation pretreatment with <I>in situ</I> detoxification, H<SUB>2</SUB>O rinsing, H<SUB>2</SUB>O/ethyl acetate (2:8, v/v) contacting, NaOH (1mM, pH 11.0) overliming and NaBH<SUB>4</SUB> (20mM) reduction, were conducted to solve the toxicity dilemma in ethanol fermentation. The irradiated straw was characterized by FT-IR, SEM and AFM. The compositions of irradiation-mediated inhibitors formed during pretreatment were analyzed with GC–MS. The detoxified straw (200gDS/L) was hydrolyzed with enzymes cocktails (∼1mg protein/gDS) optimized by a 3-factor mixture design. The hydrolysate was bioconverted to ethanol with separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) using <I>Saccharomyces cerevisiae</I>. Results showed that glucose yield varied from 60% to 80% and xylose yield from 40% to 60% in dependence on detoxification methods. Yeast growth, residual glucose and ethanol yield varied with the combination approaches. The highest glucose bioconversion (99.7%) and ethanol yield (70%) were achieved via the combined proposal of irradiation pretreatment with NaBH<SUB>4</SUB> detoxification regardless of SHF and SSF. The findings revealed that the combination proposal of irradiation pretreatment with NaBH<SUB>4</SUB> detoxification <I>in situ</I> would be a promising alternative method for bioethanol production from liginocellulosic biomass.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Irradiation pretreatment can disrupt the structure of lignocellulose and modify its morphology. </LI> <LI> Inhibitors formed during irradiation pretreatment harm yeast viability and ethanol production. </LI> <LI> Combined strategies of irradiation pretreatment with detoxification solve the toxicity dilemma. </LI> <LI> Yeast viability, residual glucose and ethanol yield are depended on detoxification method. </LI> <LI> Irradiated biomass can be performed <I>in situ</I> detoxification in solid state without extra step. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>