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Cellulose Degradation, rate

The xylan degradation rates relative to those of mannan ranged from 0.3 to 0.4 at the end of the experiment (80 hr). The same values were obtained before the additional action of mannanase on the samples treated with one of the three cellulases for 48 hr (Table III, Column 14). The corresponding values relative to the cellulose degradation rates ranged from 0.5 to 0.7 for the samples treated with cellulase only (48 hr) and after combined cellulase-mannase action (Table III, Column 15). [Pg.313]

Recently, we have shown that non-isothermal chemiluminescence measurements for oxidized cellulose provide the same rate constants of cellulose degradation as may be measured from experiments on the decay of polymerization degree determined by viscometry. This may be also taken as indirect evidence that the light emission is somehow linked with the scission of polymer chains [29]. [Pg.468]

Most often, the rates for feedstock destruction in anaerobic digestion systems are based upon biogas production or reduction of total solids (TS) or volatile solids (VS) added to the system. Available data for analyses conducted on the specific polymers in the anaerobic digester feed are summarized in Table II. The information indicates a rapid rate of hydrolysis for hemicellulose and lipids. The rates and extent of cellulose degradation vary dramatically and are different with respect to the MSW feedstock based on the source and processing of the paper and cardboard products (42). Rates for protein hydrolysis are particularly difficult to accurately determine due the biotransformation of feed protein into microbial biomass, which is representative of protein in the effluent of the anaerobic digestion system. [Pg.25]

The degradation rates of cellulose obtained with the individual cellulases were, in each case, higher than the corresponding values reached under the same conditions with beechwood holocellulose (10). The same tendency had already been found in preliminary tests with crude cellulase preparations (13 cf.23). [Pg.322]

The addition of mannanase after 48 hr of incubation with one of the three cellulases revived cellulose hydrolysis. The increase of the degradation rate was not as pronounced as in the corresponding treatments of delignified beechwood with cellulases and xylanase (JO), but the cellulose degradation reached about the same values at the end of the experiments (about 50-65% ). [Pg.323]

The well-known fact that heating of initially insoluble pulps in DMAc/LiCl improves solubility or increases the dissolution rate of the material had thus to be attributed to pronounced cellulose degradation. The observed improved solubility was evidently accompanied by a progressive DP loss of the pulp. The solubility gain was thus not an activation of the pulp, but mainly a degradation process to material of lower molecular weight which naturally exhibited a higher solubility in the cellulose solvent. [Pg.176]

The shape and size of the container which controls the rate of heat loss can be selected such that the time during which the books are subject to high temperatures can be kept small in order to minimise the effects of temperature Induced cellulose degradation. It Is anticipated that the maximum temperature In the full scale process will be less than 80 C. [Pg.45]

Table VII. Influence on Permanence by Degradation Rates, Acidity, and a-Cellulose Pulp... Table VII. Influence on Permanence by Degradation Rates, Acidity, and a-Cellulose Pulp...
The degradation of methyl cellulose and its copolymerization with AN under sonication has been studied [33]. This degradation resulted from the cavitational effects of ultrasound but the degradation rate was not found to increase with irradiation time. A water-soluble copolymer was obtained by irradiating methyl cellulose and AN in a mixed H20/HCOOH solvent at 15 °C for 30 min using 21.5-kHz ultrasound. The copolymer was identified as both block and branch with joints mainly located at methoxyl groups of methyl cellulose by means of differ-... [Pg.164]

Starch and cellulosic materials are frequently used as fillers in degradable materials. The addition of starch to LDPE in combination with a pro-oxidant increases the photooxidation rate and the formation of hydroperoxides and carbonyl groups. Starch alone does not increase the photooxidation rate. The addition of starch to LDPE increases its stability in 80°C water. Slower degradation in water is due to leaching out of the pro-oxidant. The addition of starch causes biodegradation process under soil burial conditions. Further increase in the degradation rate can be achieved by preheating polyethylene filled with starch. ... [Pg.517]


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