Application Of Thermostable Xylanases From Humicola Sp. For Pulp Improvement

Thermophilic Humicola sp. secreted thermostable xylanases when grown on wheat bran medium at 50°C. DEAE-Sephadex A-50 column chromatography of the crude xylanase separated three fractions of xylanase (I, II and III), xylanase I being homogeneous in polyacrylamide gel electrophoresis after CM-Sephadex column chromatography. The respective xylanases, including the crude xylanase, increased pulp brightness but xylanases II and III decreased the viscosity of the pulp due to CMCase activity. The crude xylanase contained lower CMCase activity than xylanases II and III. © 1994.771109111Jurasek, Paice, Biological bleaching of pulp (1988) International pulp bleaching conference, pp. 11-13. , T.J. Salvo, Orlando, Fla., TAPPI proceeding, Technical Association of the Pulp and Paper Industry, AtlantaKantelinen, Ratto, Sundquist, Ranua, Viikari, Linko, Hemicellulase and their potential role in bleaching (1988) International pulp bleaching conference, pp. 1-4. , T.J. Salvo, Orlando, Fla., TAPPI proceeding, Association of the Pulp and Paper Industry, AtlantaViikari, Kantelinen, Poutanen, Rauna, Characterization of pulps treated with hemicellulolytic enzymes prior to bleaching (1990) Biotechnology in pulp and paper manufacture, pp. 145-151. , K. Kirk, H.M. Chang, Butterworth-Heinemann Stoneham, MassMora, Comtat, Barnoud, Pla, Noe, Action of xylanases on chemical pulp fibers. I. Investigation on cell-wall modification (1986) J. Wood Chem. Technol., 6, pp. 147-165Noe, Chevalier, Mora, Comtat, Action of xylanases on chemical pulp fibers. II. Enzymatic beating (1986) J. Wood Chem. Technol., 6, pp. 167-187Yu, Tan, Chan, Deschatelets, Saddler, Production of thermostable xylanase by a thermophilic fungus, Thermoascus aurantiacus (1987) Enzyme Microb. Technol., 9, pp. 16-24Mandels, Sternberg, Recent advances in cellulase technology (1976) J. Ferment. Technol., 54, pp. 267-286Cooney, Emerson, Humicola insolens and Humicola grisea var. thermoidea (1964) Thermophilic fungi, pp. 72-79. , W.H. Freeman, Publ. Co., San Francisco, chap. 8Trevelyan, Procter, Harrison, Detection of sugars on paper chromatograms (1950) Nature, 166, pp. 444-445Lee, Forsberg, Rattray, Purification and characterization of two endoxylanases from Clostridium acetobutylicum ATCC 824 (1987) Appl. Environ. Microbiol., 53, pp. 644-650Taiz, Honigman, Production of Cell Wall Hydrolyzing Enzymes by Barley Aleurone Layers in Response to Gibberellic Acid (1976) PLANT PHYSIOLOGY, 58, pp. 380-386Tolan, Vega Canovas, The use of enzymes to decrease the Cl2 requirements in pulp bleaching (1992) Pulp Paper Canada, 93, pp. 39-4