Avicel hydrolysis

Zheng, Y. Tsao, G. T. Avicel Hydrolysis by Cellulase Enzyme in Supercritical C02. Biotechnol. Lett. 1996, 18, 451 -54. 

Zheng, Y., and Tsao, G.T. (1996) Avicel hydrolysis by cellulase enzyme in supercritical C02. Biotechnol. Lett.,... 

B) Synergistic effect on the hydrolysis of Avicel by CBH I/CBH II (pH 5.0, 37°C). CBH I and CBH II in different combinations (abscis) are mixed with Avicel (30 mg/ml). The total enzyme concentration is always 10 /iM and reducing sugars in the supernatant measured after 45 min incubation. 

D) Synergistic effect on the hydrolysis of Avicel by core I/CBH II. Same conditions as in (B). 

As further evidence, we demonstrated by paper chromatography that hydrolysis products from cellooligosaccharides by Ex-1 are Gi and G2 from G3, and Gi, G2, and G3 from G5, but only G2 from G4, Ge, CMC, cellodextrine, and insoluble cellulose such as Avicel, swollen cellulose, absorbent cotton, and filter paper (Figures 13 and 14). However, G3 was formed from G6 when Ex-1 was incubated with a mixture of G6 and Gi. There is no indication that G6 was split by this cellulase into G3 plus G3, but rather that G2 produced from G6 was transferred immediately to Gi to form G3. The results are shown in Figure 15. 

Synergistic Action of Ex-1 with other Endocellulases on the Hydrolysis of CMC and Avicel. The synergistic action of Ex-1 with F-l was investigated in the hydrolysis of both CMC and Avicel. For comparison, we investigated a similar action between S-l and F-l. The results are shown in Table V. 

The synergistic effect caused by a mixture of a typical endocellulase, F-l (CMCase), and an endocellulase of lower randomness (Avicelase) is slightly smaller than that caused by a mixture of F-l and Ex-1 (an exocellulase of Avicelase type) in the hydrolysis of both CMC and Avicel. This may be explained by the postulation that this kind of synergistic effect should be caused by the cooperation between cellulase components of extremely different types of hydrolysis. Consequently, the... 

Table VII. Hydrolysis of Avicel by Purified Cellulase Components, Alone and in Combination...

Amylodextrin is the homogeneous product of prolonged hydrolysis of starch below Tgz, terminating in the crystalline equivalent of Avicel and approximating 25 glucose monomers. The hydrolysis is normally at room temperature over intervals of months, wherein the amorphous regions are degraded and the starch crystallites are left intact. Unlike Avicel crystallites, starch crystallites may be disrupted by stress (Kerr, 1950). 

In 1972 Ogawa and Toyama (56) purified three components— A-I-a, A-I-b, and A-II-1—which were adsorbed on a gauze column during purification from Cellulase Onozuka P1500, a commercial preparation of T. viride cellulase. These three components had molecular weights of 32,000, 48,000, and 48,000 as determined by gel filtration and contained 7-16% carbohydrate. Each is reported to carry out the random hydrolysis of CM-cellulose and to degrade hydrocellulose (Avicel) and cellooligosaccharides except for cellobiose. The order of reactivity toward either cotton or Avicel was A-II-1 > A-I-b > A-I-a. The proteins adsorbed on cellulose comprised 38% of the total cellulase protein. 

High-purity fibrous cellulose, obtained by washing under very mild acidic conditions and, successively, with organic solvents, is also used in TLC. AVICEL is formed by dissolving the amorphous part of native cellulose by hydrolysis with hydrochloric acid. 

As currently understood, the cellulase complex contains the following components (listed in the order in which their action on cellulose occurs) 1. Ci is an enzyme whose action is unspecified. It is required for the hydrolysis of highly oriented solid cellulose (Cotton, Avicel, etc.) by 0-1 — 4 glucanases. 

Batch Hydrolysis of Pretreated Sugar Cane Bagasse and Avicel... 

Keywords Saline Creeping Wild Ryegrass Cellulase P-Glucosidase Tween 20 Tween 80 Bovine serum albumin - Enzymatie hydrolysis Avicel PH 101-Lignaceous residue... 

Enzyme activity loss because of non-productive adsorption on lignin surface was identified as one of the important factors to decrease enzyme effectiveness, and the effect of surfactants and non-catalytic protein on the enzymatic hydrolysis has been extensively studied to increase the enzymatic hydrolysis of cellulose into fermentable sugars [7, 9 19]. The reported study showed that the non-ionic surfactant poly(oxyethylene)2o-sorbitan-monooleate (Tween 80) enhanced the enzymatic hydrolysis rate and extent of newspaper cellulose by 33 and 14%, respectively [20]. It was also found that 30% more FPU cellulase activity remained in solution, and about three times more recoverable FPU activity could be recycled with the presence of Tween 80. Tween 80 enhanced enzymatic hydrolysis yields for steam-exploded poplar wood by 20% in the simultaneous saccharification and fermentation (SSF) process [21]. Helle et al. [22] reported that hydrolysis yield increased by as much as a factor of 7, whereas enzyme adsorption on cellulose decreased because of the addition of Tween 80. With the presence of poly(oxyethylene)2o-sorbitan-monolaurate (Tween 20) and Tween 80, the conversions of cellulose and xylan in lime-pretreated com stover were increased by 42 and 40%, respectively [23]. Wu and Ju [24] showed that the addition of Tween 20 or Tween 80 to waste newsprint could increase cellulose conversion by about 50% with the saving of cellulase loading of 80%. With the addition of non-ionic, anionic, and cationic surfactants to the hydrolysis of cellulose (Avicel, tissue paper, and reclaimed paper), Ooshima et al. [25] subsequently found that Tween 20 was the most effective for the enhancement of cellulose conversion, and anionic surfactants did not have any effect on cellulose hydrolysis. With the addition of Tween 20 in the SSF process for... 

The specific objectives of this research were to investigate (1) the effect of additives on the cellulose conversion of pretreated CWR, (2) the possible mechanism behind the effect of additives on the enzymatic hydrolysis, (3) the effect of additives on the enzyme adsorption onto several substrates, including Avicel PHIOl, pretreated CWR, and lignaceous residue of pretreated CWR. 

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