Enzymatic Hydrolysis of Cellulose Materials

cellulose Newfsprint (cut into 1.0 cm sections) or pure cellulose such as filter paper (cut into small pieces) and Solka Floe SW40 (James River Corp., Berlin, NH), and hammer-milled sulfite pulp 

5 g cellulase Any commercial products, such as Type II Cellulase (Sigma Chemical Co., St. Louis, MO) 

600-mL glass tempering beaker (jacketed) (Cole-Parmer Instrument Co., Chi-ca-go, IL) 

water bath to control the temperature of the jacketed vessel 

Set the temperature of the water bath at 50°C and circulate water through the water jacket to control the temperature. 

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The advances made in enzymatic hydrolysis of cellulosic materials (14) are also of interest. This technology involves only moderate temperature processes in simple equipment which promises to be of significantly lower capital cost than the pressure equipment associated with conventional acid wood hydrolysis processes. All of these considerations combined to lead us to study processes for ethanol production from wood, especially in an effort to obtain data for material and energy balances, and possibly for the economics. 

Viscose rayon is inherently a weak fibre, particularly when wet, therefore it is highly susceptible to damage if enzymatic hydrolysis is not controlled. The enzymatic hydrolysis of viscose fibres causes a decrease of the intrinsic viscosity from 250 to 140 ml/g and an increase in crystallinity from 29 to 39% after 44 h [34]. Strong changes of the structure, however, are not typical for the enzymatic hydrolysis of cellulosic materials. Neither cotton nor wood pulp show an essential decrease of the DP during enzymatic hydrolysis [35-37]. The kinetics of the enzymatic hydrolysis of regenerated cellulose fibres before and after acid prehydrolysis changes the kinetics from a monophasic to a biphasic first order reaction [38]. 

Beltrame, P.L., Camitti, P., Forcher, B., 2001. Enzymatic hydrolysis of cellulosic materials a kinetic study. Biotechnology and Bioengineering 31, 160—167. 

Liu, L. Chen, H., Enzymatic hydrolysis of cellulose materials treated with ionic liquid... 

Increasingly, biochemical transformations are used to modify renewable resources into useful materials (see Microbial transformations). Fermentation (qv) to ethanol is the oldest of such conversions. Another example is the ceU-free enzyme catalyzed isomerization of glucose to fmctose for use as sweeteners (qv). The enzymatic hydrolysis of cellulose is a biochemical competitor for the acid catalyzed reaction. 

A few animals (especially ruminants and termites) are able to metabolize cellulose, but even these animals depend on appropriate microorganisms in their intestinal tracts to hydrolyze the -1,4 links other animals, including man, cannot utilize cellulose as food because they lack the necessary hydrolytic enzymes. However, such enzymes are distributed widely in nature. In fact, deterioration of cellulose materials —textiles, paper, and wood —by enzymatic degradation (such as by dry rot) is an economic problem that is not yet adequately solved. Efforts to turn this to advantage through enzymatic hydrolysis of cellulose to glucose for practical food production have not been very successful (see Section 25-12). 

Influence of Fine Grinding on the Hydrolysis of Cellulosic Materials—Acid Vs. Enzymatic... 

Marsden, W. L. and P. P. Gray, "Enzymatic Hydrolysis of Cellulose in Lignocellulosic Materials," CRC Critical Review Biotech. 3 (1986) 235-276. 

Sui RGH (1951) Microbial decomposition of cellulose. Reinhold, New York Cowlind EB (1963) In Enzymatic hydrolysis of cellulose and related materials. Reese EW (ed). Macmillan, New York... 

Biological enzymatic conversion of glucose by fermentation also has been extensively studied for the production of many products one of the most important is bioethanol. Many bacteria and fungi could produce enzymes for the hydrolysis of cellulosic material. These microorganisms can be aerobic or anaerobic, mesophillic or thermophillic. ... 

Since cellulose and hemiceUulose are polymers with complex and heterogeneous structure, various equally structurally complex hydrolases are needed to effectively degrade them into monosaccharides (Somerville 2006). Therefore, an effective enzymatic hydrolysis of cellulose requires a multicomponent enzyme system, and in most anaerobes, enzymes that degrade the lignocellulosic material are congregated into a macromolecular complex, called cellulosome (Gilbert 2007). 

While this reaction is substantially exothermic (6), it provides an intriguing approach to the production of fuels from renewable resources, as the required acids (including acetic acid, butyric acid, and a variety of other simple aliphatic carboxylic acids) can be produced in abundant yields by the enzymatic fermentation of simple sugars which are, in turn, available from the microbiological hydrolysis of cellulosic biomass materials ( ] ) These considerations have led us to suggest the concept of a "tandem" photoelectrolysis system, in which a solar photoelectrolysis device for the production of fuels via the photo-Kolbe reaction might derive its acid-rich aqueous feedstock from a biomass conversion plant for the hydrolysis and fermentation of crop wastes or other cellulosic materials (4). 

Cowling, E. B., and Brown, W. (1969). Structural features of cellulosic materials in relation to enzymatic hydrolysis. Adv. Chem. Ser. 95,152-187. 

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