THE MECHANISM OF DEGRADATION OF CELLULOSE BY MYROTHECIUM CELLULASE

1957 ◽  
Vol 35 (9) ◽  
pp. 733-742 ◽  
Author(s):  
D. R. Whitaker
Keyword(s):  
Degree Of Polymerization ◽  
Average Degree ◽  
Mechanism Of Degradation ◽  
Mechanism Of Hydrolysis ◽  
Weight Number

A swollen cellulose was hydrolyzed by Myroihecium cellulase and the loss in weight, number-average degree of polymerization, and weight-average degree of polymerization were determined at various intervals. The loss in weight relative to the change in D.P. excludes endwise cleavage as the mechanism of hydrolysis. An approximate test for random cleavage is derived from the Beall–Jorgensen treatment of random cleavage processes and, within the limits of this test, the change in weight-average D.P. relative to the change in number-average D.P. is shown to be consistent with random cleavage.

THE MECHANISM OF DEGRADATION OF CELLULOSE BY MYROTHECIUM CELLULASE

1957 ◽  
Vol 35 (1) ◽  
pp. 733-742 ◽  
Author(s):  
D. R. Whitaker
Keyword(s):  
Degree Of Polymerization ◽  
Average Degree ◽  
Mechanism Of Degradation ◽  
Mechanism Of Hydrolysis ◽  
Weight Number

A swollen cellulose was hydrolyzed by Myroihecium cellulase and the loss in weight, number-average degree of polymerization, and weight-average degree of polymerization were determined at various intervals. The loss in weight relative to the change in D.P. excludes endwise cleavage as the mechanism of hydrolysis. An approximate test for random cleavage is derived from the Beall–Jorgensen treatment of random cleavage processes and, within the limits of this test, the change in weight-average D.P. relative to the change in number-average D.P. is shown to be consistent with random cleavage.

THE MECHANISM OF DEGRADATION OF A CELLODEXTRIN BY MYROTHECIUM CELLULASE

1956 ◽  
Vol 34 (1) ◽  
pp. 488-494 ◽  
Author(s):  
D. R. Whitaker
Keyword(s):  
Degree Of Polymerization ◽  
Average Degree ◽  
Transfer Reactions ◽  
Mechanism Of Degradation ◽  
Specific Activities

A cellodextrin with a number-average degree of polymerization (D.P.) of 24 was hydrolyzed by Myrothecium cellulase in the presence of C14-labelled cellobiose. The specific activities of cellotriose and cellotetraose isolated at various stages of the hydrolysis were less than 20% of that of cellobiose isolated at the same time. It is concluded that transfer reactions involving cellobiose contributed little to the formation of cellotriose and cellotetraose. The ratio moles of cellotriose formed/mole of cellobiose formed was at least 0.7 and the corresponding ratio for cellotetraose at least 0.4. The number-average D.P. of the substrate decreased slightly during the hydrolysis. The results exclude a degradation of the substrate by cleavage of cellobiose units from the ends of its chains but are consistent with degradation by random cleavage.

THE MECHANISM OF DEGRADATION OF A CELLODEXTRIN BY MYROTHECIUM CELLULASE

1956 ◽  
Vol 34 (3) ◽  
pp. 488-494 ◽  
Author(s):  
D. R. Whitaker
Keyword(s):  
Degree Of Polymerization ◽  
Average Degree ◽  
Transfer Reactions ◽  
Mechanism Of Degradation ◽  
Specific Activities

A cellodextrin with a number-average degree of polymerization (D.P.) of 24 was hydrolyzed by Myrothecium cellulase in the presence of C14-labelled cellobiose. The specific activities of cellotriose and cellotetraose isolated at various stages of the hydrolysis were less than 20% of that of cellobiose isolated at the same time. It is concluded that transfer reactions involving cellobiose contributed little to the formation of cellotriose and cellotetraose. The ratio moles of cellotriose formed/mole of cellobiose formed was at least 0.7 and the corresponding ratio for cellotetraose at least 0.4. The number-average D.P. of the substrate decreased slightly during the hydrolysis. The results exclude a degradation of the substrate by cleavage of cellobiose units from the ends of its chains but are consistent with degradation by random cleavage.

Combined Implementation of Dynamic Rating-based Protection and Calculating the Average Degree of Polymerization for Power Transformers

2021 ◽  
Vol 141 (7) ◽  
pp. 528-534
Author(s):  
Kohei Ito ◽  
Mutsumi Aoki ◽  
Toru Amau ◽  
Tetsuo Otani ◽  
Tatsuya Ozawa ◽  
...  
Keyword(s):  
Degree Of Polymerization ◽  
Average Degree ◽  
Power Transformers

scholarly journals Extraction and Characterization of Inulin-Type Fructans from Artichoke Wastes and Their Effect on the Growth of Intestinal Bacteria Associated with Health

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Zahraa Zeaiter ◽  
Maria Elena Regonesi ◽  
Sofia Cavini ◽  
Massimo Labra ◽  
Guido Sello ◽  
...  
Keyword(s):  
Intestinal Bacteria ◽  
Degree Of Polymerization ◽  
Average Degree ◽  
Globe Artichoke ◽  
Ethanol Precipitation ◽  
Long Chain ◽  
Simpler Method

Globe artichoke is an intriguing source of indigestible sugar polymers such as inulin-type fructans. In this study, the effect of ultrasound in combination with ethanol precipitation to enhance the extraction of long chain fructans from artichoke wastes has been evaluated. The inulin-type fructans content both from bracts and stems was measured using an enzymatic fructanase-based assay, while its average degree of polymerization (DP) was determined by HPLC-RID analysis. Results show that this method provides artichoke extracts with an inulin-type fructans content of 70% with an average DP between 32 and 42 both in bracts and in stems. The prebiotic effect of long chain inulins from artichoke extract wastes was demonstrated by its ability to support the growth of five Lactobacillus and four Bifidobacterium species, previously characterized as probiotics. Besides, we considered the possibility to industrialize the process developing a simpler method for the production of inulin-type fructans from the artichoke wastes so that the artichoke inulin preparation could be suitable for its use in synbiotic formulations in combination with different probiotics for further studies including in vivo trials.

Chain conformation and average degree of polymerization of the sequences in copolyesters

1989 ◽  
Vol 156-157 ◽  
pp. 420-422 ◽  
Author(s):  
E. Olbrich ◽  
D. Chen ◽  
P. Lindner ◽  
H.G. Zachmann ◽  
H. Benoit
Keyword(s):  
Degree Of Polymerization ◽  
Chain Conformation ◽  
Average Degree
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