普渡大學(xué)（Purdue University）的研究人員發(fā)現(xiàn),，將植物的稈，葉或纖維素以熱水進(jìn)行前處理,，將有利于生質(zhì)酒精的大量制造,，相較于未處理的原料，其產(chǎn)率可提高3~4倍,。研究人員發(fā)現(xiàn)在熱水處理過(guò)的植物細(xì)胞壁中，有許多微小的孔洞產(chǎn)生,，能增加纖維素分解酵素作用的表面積,，更有效的將纖維素分解為小分子的葡萄糖，提供酵母菌制作酒精的原料,。此研究發(fā)表于4月26日的Biotechnology and Bioengineering期刊,。由Nathan Mosier教授主導(dǎo)研究進(jìn)行。
研究人員利用高分辨率的影像及化學(xué)分析,，來(lái)觀察以熱水前處理過(guò)的植物細(xì)胞壁,，發(fā)現(xiàn)細(xì)胞壁上被擴(kuò)大的孔洞能使酵素輕易的作用，提高纖維素被分解的速率,，這也將改善美國(guó)生質(zhì)酒精生產(chǎn)的限制,，因?yàn)檫^(guò)去大多是利用玉米粒或甘蔗等作物作為制造生質(zhì)酒精的原料,，可能會(huì)影響經(jīng)濟(jì)作物的出口值,，或影響動(dòng)物飼料的來(lái)源，若能以其它植物性纖維素作為生質(zhì)酒精的原料,，將可破除這些限制,，更有利于工業(yè)上大量生質(zhì)酒精的制造。
（編譯/陳瑞娟） (資料來(lái)源 : Bio.com)
原始出處:
Article
Microscopic examination of changes of plant cell structure in corn stover due to hot water pretreatment and enzymatic hydrolysis
Meijuan Zeng 1 2, Nathan S. Mosier 1 2, Chia-Ping Huang 4, Debra M. Sherman 4, Michael R. Ladisch 1 2 3 *
1Laboratory of Renewable Resources Engineering, Potter Engineering Center, 500 Central Drive, Purdue University, West Lafayette, Indiana 47907; telephone: 765-494-7022, fax: 765-494-7023
2Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907
3Weldon School of Biomedical Engineering, Purdue University, 206 S. Intramural Drive, West Lafayette, Indiana 47907
4Life Science Microscopy Facility, Purdue University, S-052 Whistler Building, 170 S. University Street, West Lafayette, Indiana 47907
email: Michael R. Ladisch ([email protected])
*Correspondence to Michael R. Ladisch, Laboratory of Renewable Resources Engineering, Potter Engineering Center, 500 Central Drive, Purdue University, West Lafayette, Indiana 47907; telephone: 765-494-7022, fax: 765-494-7023.
Funded by:
U.S. Department of Agriculture
U.S. Department of Energy
Agricultural Research Programs at Purdue University
Purdue University; Grant Number: IFAFS 00-52104-9663, DE-FC36-01GO11075
Keywords
corn stover ?particle size ?hot water pretreatment ?enzymatic hydrolysis ?SEM image ?glucose conversion ?accessible surface area
Abstract
Particle size associated with accessible surface area has a significant impact on the saccharification of plant cell walls by cellulolytic enzymes. Small particle sizes of untreated cellulosic substrate are more readily hydrolyzed than large ones because of higher specific surface area. Pretreatment enlarges accessible and susceptible surface area leading to enhanced cellulose hydrolysis. These hypotheses were tested using ground corn stover in the size ranges of 425-710 and 53-75 祄. Ultrastructural changes in these particles were imaged after treatment with cellulolytic enzymes before and after liquid hot water pretreatment. The smaller 53-75 祄 corn stover particles are 1.5?more susceptible to hydrolysis than 425-710 祄 corn stover particles. This difference between the two particle size ranges is eliminated when the stover is pretreated with liquid hot water pretreatment at 190癈 for 15 min, at pH between 4.3 and 6.2. This pretreatment causes ultrastructural changes and formation of micron-sized pores that make the cellulose more accessible to hydrolytic enzymes. Biotechnol. Bioeng. 2007;97: 265-278. © 2006 Wiley Periodicals, Inc.
