Enzymatic digestion of cellulose

Table VIII. Growth of Yeasts on Enzymatic Digests of Cellulose...

Lignin renK)val was limits to about 30% for a batch reactor without acid addition and dropped to about 20% when dilute sulfiiric acid was used, and the enzymatic digestibility of cellulose in the residual solids increased with xylan removal for both, consistent with observations by others. On the other hand, introducing flow of liquid tiuough the solids enhanced renK)val of lignin... 

Figure 6. Effect ofxylan removal (a) and lignin removal (b) on enzymatic digestibility of cellulose produced by hemicellulose hydrolysis of com stover at the conditions noted.

Yang, B., and Wyman, C. E., 2000, Effect of xylan and lignin removal by batch and flowthrough pretreatment on the enzymatic digestibility of com stover cellulose, Biotechnol. Bioeng. 86 88-95. 

Circumventing the lignin barrier to enzymatic digestion of the polysaccharides occurs when wood is finely ground. Below a certain wood particle size, the polysaccharides (celluloses and hemicellu-... 

C. Boisset, C. Fraschini, M. Schulein, B. Henrissat, and H. Chanzy, Imaging the enzymatic digestion of bacterial cellulose ribbons reveals the endo character of the cellobiohydrolase Cel6A from Humicola insolens and its mode of synergy with cellobiohydrolase Cel7A, Appl. Environ. Microbiol., 66 (2000) 1444-1452. 

The nucleosides obtained by enzymatic digestion of t-RNA were separated by bidimensional chromatography using Merck cellulose layered on 20 x 50 cm aluminum sheets. The elution in the first direction was performed with n-butanol-isobutyric acid-ammonium hydroxide, conc.-water (75 37.5 2.5 25, v/v) mixture for 24 hr at 20-21°C, in an unsaturated chamber. The chromatographic plate was dried with a fan for 3 hr at 20°C, after the first elution. Elution in the second direction was performed for 4 hr with the mixture ammonium sulfate (saturated solution)-0.1 M sodium acetate (pH 6)-isopropanol (79 19 2, v/v). The separated compounds were visualized in UV light at 254 mn. 

TLC has been combined with electrophoresis to facilitate nucleotide separations. Thus, Berquist (1965) mapped the enzymatic digests of RNA by separating 17 ohgonucleotides and mononucleotides on a cellulose layer. Electrophoresis was first run at pH 2.5 and 50 V/cm, followed by two successive chromatographic developments at a right angle to the electrophoretic dimension. Diels and Wachter (1980) and Hashimoto et al. (1981) also combined gel electrophoresis and TLC in their RNA sequencing studies. 

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