ISSN:
1432-072X
Keywords:
Clostridium thermocellum
;
Cellulose
;
Cellobiose
;
Cellulase
;
Cellulolytic enzyme complex
;
Endo-β-glucanase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Clostridium thermocellum, strain JW20 (ATCC 31449) when growing in cellulose produces a cellulolytic enzyme system, that at the early stage of the fermentation is largely bound to the substrate. As cellulose is consumed the bound enzyme is released as free enzyme to the culture fluid. The bound enzyme fraction extracted with distilled water from the cellulose contains two major components, a large complex (Mr≃100×106) and a small complex Mr≃4.5×106) which were separated by gel filtration and sucrose solved by affinity chromatography into a complex that binds to the column and into a non-bindable mixture of proteins. All four fractions have endo-β-glucanase activity but only the two bound complexes and the free bindable complex hydrolyze crystalline cellulose with cellobiose as the main product. These three complexes are qualitatively similar in that they each contain about 20 different polypeptides (Mr values from 45,000 to 200,000) of which about ten are major components. However, the relative amounts of some of the peptides in the complexes differ. At least four polypeptides of the complexes have endo-β-glucanase activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00413021
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