Challenges in enzymatic hydrolysis and fermentation of pretreated Arundo donax revealed by a comparison between SHF and SSF
메타 데이터
바이오화학분류
바이오플라스틱
플라스틱
기타
바이오정밀화학
용매
화학제품
연료
기타
화장품용 기능성소재
계면활성제⁄증점제
기타
의료용 화학소재
식품첨가제
논문
Challenges in enzymatic hydrolysis and fermentation of pretreated Arundo donax revealed by a comparison between SHF and SSF
학술지
Process biochemistry
저자명
Ask, Magnus; Olofsson, Kim; Di Felice, Tommaso; Ruohonen, Laura; Penttilä , Merja; Lidé n, Gunnar; Olsson, Lisbeth
초록
<P><B>Highlights</B></P><P>► SHF of <I>Arundo donax</I> resulted in higher ethanol yield and titer than SSF. ► Water-soluble compounds in the raw material inhibited the enzymatic hydrolysis. ► Addition of hemicellulases increased the ethanol yield in both SHF and SSF. ► Acetic acid present in the slurry affected the xylose consumption negatively.</P> <P><B>Abstract</B></P><P>The perennial herbaceous crop <I>Arundo donax</I> is a potential feedstock for second-generation bioethanol production. In the present work, two different process options were investigated for the conversion of two differently steam-pretreated batches of <I>A. donax</I>. The pretreated raw material was converted to ethanol with a xylose-consuming <I>Saccharomyces cerevisiae</I> strain, VTT C-10880, by applying either separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF). The highest overall ethanol yield and final ethanol concentration were achieved using SHF (0.27gg<SUP>−1</SUP> and 20.6gL<SUP>−1</SUP> compared to 0.24gg<SUP>−1</SUP> and 19.0gL<SUP>−1</SUP> when SSF was used). The performance of both SHF and SSF was improved by complementing the cellulolytic enzymes with hemicellulases. The higher amount of acetic acid in one of the batches was shown to strongly affect xylose consumption in the fermentation. Only half of the xylose was consumed when batch 1 (high acetic acid) was fermented, compared to that 94% of the xylose was consumed in fermentation of batch 2 (lower acetic acid). Furthermore, the high amount of xylooligomers present in the pretreated materials considerably inhibited the enzymatic hydrolysis. Both the formation of xylooligomers and acetic acid thus need to be considered in the pretreatment process in order to achieve efficient conversion of <I>A. donax</I> to ethanol.</P>