文献类型：期刊文献

英文题名：New insights into enzymatic hydrolysis of heterogeneous cellulose by using carbohydrate-binding module 3 containing GFP and carbohydrate- binding module 17 containing CFP

作者：Gao, Shuhong[1,2];You, Chun[2];Renneckar, Scott[3];Bao, Jie[1];Zhang, Yi-Heng Percival[2,4,5]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Sch Biotechnol, Shanghai 200237, Peoples R China;[2]Virginia Tech, Biol Syst Engn Dept, Blacksburg, VA 24061 USA;[3]Virginia Tech, Sustainable Biomat Dept, Blacksburg, VA 24061 USA;[4]Cell Free Bioinnovat Inc, Blacksburg, VA 24060 USA;[5]Gate Fuels Inc, Blacksburg, VA 24060 USA

年份：2014

卷号：7

期号：1

外文期刊名：BIOTECHNOLOGY FOR BIOFUELS

收录：;EI(收录号：20141217475237);WOS:【SCI-EXPANDED(收录号:WOS:000333012400001)】；

基金：This work was supported by the Open Funding Project of the State Key Laboratory of Bioreactor Engineering of China (2060204) and the Biological Systems Engineering of Virginia Tech (USA) to PZ. SG was partially funded by the China Scholarship Council. Additionally, the work was supported in part by the United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) National Research Initiative (NRI) competitive grants program (grant number: 2010-65504-20429).

语种：英文

外文关键词：Amorphous cellulose; Enzymatic hydrolysis of heterogeneous cellulose; Carbohydrate-binding module; Crystalline cellulose; Mono-cherry fluorescent protein

摘要：Background: The in-depth understanding of the enzymatic hydrolysis of cellulose with heterogeneous morphology (that is, crystalline versus amorphous) may help develop better cellulase cocktail mixtures and biomass pretreatment, wherein cost-effective release of soluble sugars from solid cellulosic materials remains the largest obstacle to the economic viability of second generation biorefineries. Results: In addition to the previously developed non-hydrolytic fusion protein, GC3, containing a green fluorescent protein (GFP) and a family 3 carbohydrate-binding module (CBM3) that can bind both surfaces of amorphous and crystalline celluloses, we developed a new protein probe, CC17, which contained a mono-cherry fluorescent protein (CFP) and a family 17 carbohydrate-binding module (CBM17) that can bind only amorphous cellulose surfaces. Via these two probes, the surface accessibilities of amorphous and crystalline celluloses were determined quantitatively. Our results for the enzymatic hydrolysis of microcrystalline cellulose (Avicel) suggested that: 1) easily accessible amorphous cellulose on the surface of Avicel is preferentially hydrolyzed at the very early period of hydrolysis (that is, several minutes with a cellulose conversion of 2.8%); 2) further hydrolysis of Avicel is a typical layer-by-layer mechanism, that is, amorphous and crystalline cellulose regions were hydrolyzed simultaneously; and 3) most amorphous cellulose within the interior of the Avicel particles cannot be accessed by cellulase. Conclusions: The crystallinity index (CrI), reflecting a mass-average (three-dimensional) cellulose characteristic, did not represent the key substrate surface (two-dimensional) characteristic related to enzymatic hydrolysis.