http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cha, Young-Lok,Yang, Jungwoo,Ahn, Jong-Woong,Moon, Youn-Ho,Yoon, Young-Mi,Yu, Gyeong-Dan,An, Gi Hong,Choi, In-Hu Springer Berlin Heidelberg 2014 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.37 No.9
<P>A CO<SUB>2</SUB>-added ammonia explosion pretreatment was performed for bioethanol production from rice straw. The pretreatment conditions, such as ammonia concentration, CO<SUB>2</SUB> loading level, residence time, and temperature were optimized using response surface methodology. The response for optimization was defined as the glucose conversion rate. The optimized pretreatment conditions resulting in maximal glucose yield (93.6 %) were determined as 14.3 % of ammonia concentration, 2.2 MPa of CO<SUB>2</SUB> loading level, 165.1 °C of temperature, and 69.8 min of residence time. Scanning electron microscopy analysis showed that pretreatment of rice straw strongly increased the surface area and pore size, thus increasing enzymatic accessibility for enzymatic saccharification. Finally, an ethanol yield of 97 % was achieved via simultaneous saccharification and fermentation. Thus, the present study suggests that CO<SUB>2</SUB>-added ammonia pretreatment is an appropriate process for bioethanol production from rice straw.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s00449-014-1165-x) contains supplementary material, which is available to authorized users.</P>
Cha, Young-Lok,An, Gi Hong,Yang, Jungwoo,Moon, Youn-Ho,Yu, Gyeong-Dan,Ahn, Jong-Woong Elsevier 2015 RENEWABLE ENERGY Vol.80 No.-
<P><B>Abstract</B></P> <P>One major obstacle of simultaneous saccharification and fermentation (SSF) is that enzymatic hydrolysis in SSF is conducted at non-optimal temperature. To break through this bottleneck, thermotolerant <I>Saccharomyces cerevisiae</I> strains mbc 1-4 were screened by spot-assay from respiration-deficient mutants induced by ethidium bromide. When four strains placed in liquid medium, the strains exhibited significant increased growth and fermentability at 42 °C in comparison to the host. Consequently, <I>S. cerevisiae</I> mbc 2 was selected to be the most suitable for bioethanol production at 42 °C. <I>Miscanthus</I> was pretreated with 1.5 M NaOH at 150 °C for 30 min in 1 L-vessel. As a result, 42.6% of solids containing 77.9% cellulose were recovered. Next, SSF was conducted with pretreated <I>Miscanthus</I> containing 3% glucan to estimate the fermentability of <I>S. cerevisiae</I> mbc 2 at 42 °C. In results, Ethanol concentration and theoretical ethanol yield by <I>S. cerevisiae</I> mbc 2 in 48 h were 15.3 g/L and 90.1%, respectively, whereas those by the control were 8.3 g/L and 49.3%, respectively. In addition, SSF with increased substrate concentration upto 9% glucan resulted in 86.3% and 82.2% of theoretical ethanol yield, respectively. Thus, our approach for SSF with high solid loading using thermotolerant <I>S. cerevisiae</I> mbc 2 contributes to process and microbial strain development for bioethanol production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel thermotolerant yeast strains were induced and isolated by random mutagenesis using EtBr. </LI> <LI> The thermotolerant strains were verified to grow and ferment better than its control at 42 °C. </LI> <LI> The selected strain mbc 2 was verified to be suitable for SSF of pretreated <I>Miscanthus</I> at 42 °C. </LI> <LI> Furthermore, the selected strain mbc 2 was proven to be suitable for SSF with high solids loading of <I>Miscanthus.</I> (e.g., 9% glucan). </LI> </UL> </P>