美國普渡大學一項新的研究顯示，植物細胞中的微孔可能是綠色燃料的希望,。研究人員發(fā)現(xiàn)玉米稈顆粒在被用于生產(chǎn)乙醇時，發(fā)生了之前未知的結(jié)構(gòu)變化,。研究人員指出,，他們的發(fā)現(xiàn)將有助于開發(fā)出利用植物進行大規(guī)模乙醇生產(chǎn)的一種可行方法。
他們的研究證實,，預先用熱水處理谷物植株組織,，能夠通過暴露植物細胞壁的微孔來增加反應的接觸表面積，從而有助于細胞壁的降解,。
普渡大學的研究人員指出,，這種方法將加工技術(shù)與植物生理學聯(lián)系在了一起。這項研究的結(jié)果發(fā)表在4月26日的Biotechnology and Bioengineering雜志上,。
利用高分辨率的成像和化學分析方法，研究人員證實,，這種預處理擴展了玉米稈細胞中的反應面積,。在接下來的處理步驟中，這些張大的孔更容易被將纖維素轉(zhuǎn)化成葡萄糖的酶攻擊,。產(chǎn)生的葡萄糖被發(fā)酵成乙醇,。
論文的作者還指出，利用纖維素產(chǎn)生乙醇要比現(xiàn)有的幾種工業(yè)加工方法更具優(yōu)勢,。目前,，幾乎所有的工業(yè)乙醇都是由谷物或甘蔗中的淀粉加工而成。這種浪費大量糧食資源的方法使乙醇的產(chǎn)量很有限,。而秸稈纖維素乙醇則有助于突破這個局限性,。
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
Magnified image of cornstalk particle
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.
Received: 11 July 2006; Accepted: 30 November 2006
