Enzymes of the Cellulase Complex

Abstract

Preece, 1. A,, and M. MacDougull: Enzymic degradation of cereal hemicelluloses. 11. Partci-n of pentosan degradation. J. Inst. Brewing 64 (1958), 489 -500. Fukui, S., and M . Sato: On the xylanase system of Aspergillus burutae. Bull. Agr. Chem. SOC. Japan 21 (1957), 392-393. Susuki, T., and M . Inaoku: Studies on the xylanases from Aspergillus niger. Part 11. Fractionation of xylanases with DEAE Sephadex. Mem. Ehime Univ. Sect. VI. 1967,157-164. Builey, R . W., B. D. E. Gaillard: Carbohydrases of the rumen ciliate Epidinium ecaudatum (Crawley). Hydrolysis of plant hemicellulose fractions and P-linked glucose polymers. Biochem. J. 95 (19651, 758-766. Van Doursluer, E., H. Kersters-Hilderson and C. K . De Bruyne: Mechanism of action o f P-xylosidase from Bacillus pumilus.

Cellulase and Xylanase Production by Yeasts of the Genus Trichosporon

“…Analysis of the soluble products formed from cellulose shows clear differences between the cellulase preparations from species of the genera Trichosporon, Trichoderma and Myrothecium. This probably reflects a different composition of the complex of enzymes required to produce glucose from cellulose, possibly in the P-glucosidase activity or in the exo-(I +4)-pglucanase activity of the C, component (King & Vessal, 1969) as indicated by the proportions of cellobiose and glucose in the mixture of products. Examination by polyacrylamide gel electrophoresis also distinguished between the proteins present in the culture filtrates of species of Trichosporon, Trichoderma and Myrothecium.…”

Partial Characterization of Cx Cellulase and Cellobiase from Ripening Tomato Fruits

“…These experiments indicate that tissues within the locules of tomato fruits contain at least two cellulolytic enzymes (C. cellulase and cellobiase), which are similar in general properties to cellulolytic enzymes of fungal origin (15 (15,30) and is also true of other higher plant C,, cellulase preparations (2, 23).…”

“…Microorganisms are known to produce at least four different types of enzymes which have distinctly different roles in the degradation of cellulose (15,20). The least understood of these enzymes is the component which was termed "C1 cellulase"…”

“…This enzyme was postulated to initiate enzymatic attack on insoluble cellulose. Conclusive evidence for the existence of C, cellulase as an entity distinct from other cellulolytic enzymes has been presented recently, and the mechanism of catalysis by this component is uncertain (15,20,32). In addition to C,, cellulolytic microorganisms produce hydrolytic enzymes termed C1 cellulase, exocellulase, and cellobiase.…”

“…Both enzymes have broad substrate specificities and substrates in common. However, they differ markedly in Km for different substrates (20), mode of attack (15,20), and susceptibility to inhibitors (28,29). Thus, several means exist for distinguishing between the activities of exoglucanases and cellobiases in spite of the facts that their substrate specificities overlap and that the product of each reaction is glucose.…”