纖維性質與蛋白質添加物對纖維素內切酶吸附及水解之影響

近年來，由於工業發展迅速，使得石化能源被大量的使用。利用生質物產生能源為解決石化能源日漸枯竭的方法之一。生物精煉的主要程序為將生質物中的纖維素經由酵素水解轉化成可發酵的醣，再利用微生物發酵轉化成其他化學品如酒精等。其中酵素水解為整個程序中的關鍵步驟，主要原因在於纖維素的高度結晶性與緊密排列使得醣化水解變得非常困難。木質纖維素是地球上蘊藏最豐富的可再生資源，本論文為探討木質纖維素與酵素吸附及水解之間的關係。實驗以桉樹經過硫酸鹽法製程，再篩分成不同大小，而後進行低溫吸附以及高溫水解實驗。經實驗得知，桉樹漿在低溫 (4oC) 情況下，全漂漿其Fibercare最大吸附量比未漂漿來的高；而高溫 (40 oC) 水解情況下，則為未漂漿之Fibercare最大吸附量比全漂漿大。另外，利用稻稈蒸氣爆碎漿進行纖維大小對於蛋白質吸附以及酵素水解產率的比較，低溫吸附以及高溫水解實驗中，R-100皆得到較大的蛋白質吸附值。除了測定游離蛋白質含量外，也測定分子量和還原糖來觀察纖維的水解程度。除此之外，實驗也探討Fibercare與BSA以及Lysozyme的交互關係。研究顯示，BSA及Lysozyme等界面活性劑會優先吸附於紙漿纖維外部的木質素，讓水解蛋白正確吸附在目標物纖維素，因而增加了水解酶的效率，改變水解機制。

關鍵字

酵素可及性；吸附；纖維素內切酶水解；木質素；纖維大小

並列摘要

In recent years, due to the rapid industrial development, a great deal of fossil energy is used. It is one of ways that ultimate biomass to generate energy for solving the problem of fossil energy dried up gradually. One of the main steps in bio-refining procedures for cellulose in biomass turns into fermentable sugars through the hydrolysis, then transfer to other chemicals such as alcohol by microbial. Due to a high degree of crystallinity of cellulose and closely packed accumulation of saccharification, hydrolysis becomes very difficult. Lignocellulose is the most abundant renewable resources on the Earth, this paper is to explore the relationship between the lignocellulosic enzyme adsorption and hydrolysis. Eucalypt pulps deal with sulfate process, and then sieving into different sizes, then proceeding low-temperature adsorption experiments and high-temperature hydrolysis. The cases of the experimental results, the fully bleached pulp achieve Fibercare maximum adsorption than unbleached pulp at low temperature (4oC); the unbleached pulp achieve maximum adsorption capacity at high temperature (40 oC) hydrolysis circumstances, whereas. In addition, comparison of protein adsorption and enzymatic hydrolysis yield of rice straw steam explosion pulp, R-100 gets larger protein adsorption values. Besides, molecular weight changes and reducing sugar released were monitored for digestibility of the samples. To explore the interaction of cellulase and pulp on different conditions among lignin contents and adding BSA and Lysozyme. We observed that irrelevant proteins preferentially adsorbed on pulp surface with higher lignin contents than cellulase, and the addition of BSA or Lysozyme strengthened the above trend. Studies have shown that surfactants such as BSA and Lysozyme preferentially adsorbed to the lignin of the pulp fiber. Hydrolyzed protein adsorb correctly in the target cellulose, thus increasing the efficiency of the hydrolytic enzymes, changing the hydrolysis mechanism.

並列關鍵字

Accessibility ； Adsorption ； Endoglucanase ； Hydrolysis ； Lignin ； Particle size

參考文獻

Chandra, R., Bura, R., Mabee, W., Berlin, A., Pan, X., Saddler, J. 2007. Substrate pretreatment: The key to effective enzymatic hydrolysis of lignocellulosics Biofuels, 67-93.

Chandra, R., Ewanick, S., Chung, P., Au-Yeung, K., Rio, L., Mabee, W., Saddler, J. 2009. Comparison of methods to assess the enzyme accessibility and hydrolysis of pretreated lignocellulosic substrates. Biotechnology letters, 31(8), 1217-1222.

Dien, B.S., Sarath, G., Pedersen, J.F., Sattler, S.E., Chen, H., Funnell-Harris, D.L., Nichols, N.N., Cotta, M.A. 2009. Improved sugar conversion and ethanol yield for forage sorghum (Sorghum bicolor L. Moench) lines with reduced lignin contents. BioEnergy Research, 2(3), 153-164.

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纖維性質與蛋白質添加物對纖維素內切酶吸附及水解之影響

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