Cellulose activity

Activation energy Activation of cellulose Activation parameters Activation volume Activators... 

Cellulose activated with ethylenediarnine [107-15-3] is used to prepare high molecular-weight cellulose butyrate (23). Cellulose so activated has a larger measured surface area (120 m /g) than cellulose activated with acetic acid (4.8 m /g). The diamine is removed with water, followed by solvent exchange with acetic acid and butyric acid before esterification. 

Several procedures have been suggested for heat-mediated cellulose activation, e.g., by using the reaction solvent itself as the heating medium. This activation, first proposed by Ekmanis, is based upon the fact that the vapor pressure of DMAc, near, or at its boiling point is sufficiently high to induce efficient fiber penefration and swelling [50]. Heat activation is considered more... 

Cellulose activation has been achieved by heating the polymer with dry LiCl, at 110 °C, under reduced pressure, 2 mm Hg, followed by addition of DMAc. It is important to introduce the solvent while the system is maintained under reduced pressure, in order to avoid hornification [56]. As expected, the activation conditions employed were found to be dependent on cellulose structure, samples with high DP and high Ic required pre-treatment, i.e., mer-cerization (cotton linters), and/or longer activation time. This solubilization... 

Cellulase Cellulase Cellulosic activity productivity substrate (FPUVmL) (FPU7L.h) Ref. 

Figure 5. Data of Wilke and Yang on adsorption of Ci and Cx cellulose activity (in terms of FP units) on —20-mesh Wiley-milled newsprint. Distribution coefficient = 0.04 (FP units/mL)/(FP units/g solids).

In the same context, results from cotton vary, too. Halliwell and Griffin (9), for example, report that cotton was solubilized to the extent of 20% by a Ci component from T. koningii cellulase, despite the fact that it was free from contaminating Cx (CM-cellulose) activity. Since this compares with a value of between 2 and 4% for the Ci components of F. solani, T. koningii, and P. funiculosum isolated in our laboratory, it seems reasonable to assume that there is some fundamental difference between the two components, bearing in mind that the substrates used in both studies were identical, as far as one can ascertain. 

All assays (21) contained C 180 / g protein, 1000 units of Cx (CM-cellulose) activity (26), and 100 units of /3-glucosidase where necessary, /3-glucosidase isolated from the cellulase of F. solani (21) was added. The a-celluloses were the residues left after delignification and extraction with 18% (w/v) NaOH of oat straw, birch wood, and ryegrass. 

Figure 1. Elution profiles of cellulase activity from Sephadex G-100 gel chromatographs of crude extracts of auxin-treated pea apices. BS cellulose activity has an elution volume corresponding to a molecular weight of 20,000. BI cellulase activity dissolves in 1M NaCl and elutes with a molecular weight of 70,000. These values correspond to those observed for purified cellulases (3), indicating that the enzymes were not altered in molecular weight during purification, and could be effectively separated by differential extraction.

Cel6A (CBH II) -20% of total secreted protein Various isoenzymes (pi 5.1-6.3 pi 5.9+) (difficult to purify) 53kDa+ pi 5.9+ CBD (N-terminal) From non-reducing end Single displacement— Inversion of the anomeric carbon Attacks amorphous and crystalline cellulose Active on P-glucan... 

Catalase Activity, 791 Cellulose Activity, 791 Chymotrypsin Activity, 793 Diastase Activity (Diastic Power), 793 a-Galactosidase Activity, 794 [i-Glucanasc Activity, 795 Glucoamylase Activity... 

Adsorbent Agent capable of holding other molecules onto its surface by physical or chemical (chemisorption) means Powdered cellulose, activated charcoal... 

Fig. 7. Effect of sucrose concentration on thermometric signal in steady-state. Invertase was immobilized on bead cellulose activated by cyanuric chloride [27]...

A process has been developed for bleaching textile materials containing cellulose activated by microwave radiation [65]. High degree of whiteness and capil-... 

Accordingly, the increase in DNA, RNA, protein and cellulose activity, observed earlier by Smith et al. (1971) in Agropyron on treatment with propyzamide, can be considered as effects of secondary importance. 

Arrow indicates the position of start. The patterns were not corrected for electroendosmosis. Electrophoretic conditions 11 X 2 cm. cellulose acetate film, using veronal buffer at pH 8.6 (I = 0.05) 2-hour run at 0-2°C. and at constant current of 0.6 ma./cm. The cellulose activity was assayed by CMC-saccharification and expressed in terms of the absorbancy at 660 n.m. 

Figure 6. Electrolytic reduction of a cellulose from the fungus Penicillium notatum at pH 7.6 and room temperature. Current in ma. (A) cellulose activity (% of initial activity) (O) (9)...

Figure 10. Loss of cellulose activity in contact with highly susceptible substrate (Sweco 70-93.8% < 53fi)...

Cellulose activity—1.26 FP units substrate concentration 10% total reaction time—40 hr. 0.5 liter glass stirred tank reactor... 

Figure I. The growth, excretion of protein, and the cellulose activity in the menstruum. The activity of the enzyme was expressed in terms of solubilized cellulose (10)...

Cellulose activated with epichlorohydrin has been treated with glycine and then coupled with a-amylase via a carbodi-imide mediator. Glucoamylase was also immobilized by a carbodi-imide-mediated reaction with epichlorohydrin-activated cellulose, which had previously been treated with 6-aminohexanoic acid, or by reaction with diazotized benzidine previously coupled to epichloro-hydrin-activated cellulose. Immobilized 4-chloromercuribenzoate was prepared by reaction with 1,6-diaminohexane coupled to epichlorohydrin-activated cellulose, and used for the affinity chromatographic purification of a-amylase and glucoamylase. 

Adsorption onto tannin coupled to aminohexyl-cellulose Active immobilized enzyme 493 ... 

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