title: Improvement of the yield of physiologically active oligosaccharides in continuous hydrolysis of chitosan using immobilized chitosanases.
abstract: The continuous production of chitosan oligosaccharides using a packed-bed enzyme reactor was investigated as to the effects of the operation conditions on the yield of pentamers and hexamers of chitosan oligosaccharides. A column reactor packed with immobilized chitosanases prepared by the multipoint attachment method was used for continuous hydrolysis of chitosan. In this reactor, the decrease of the yield of the target intermediate oligosaccharides due to axial mixing was negligible. The surface enzyme density of the support and flow rate of the substrate solution significantly affected the maximum yield of pentamers and hexamers. These effects were summarized as a correlation with the Damköhler number (Da), defined as the ratio of the maximum reaction rate to the maximum mass transfer rate. The optimum condition was determined based on Da. Under the optimized condition (Da = 0.12), pentamers and hexamers could be produced continuously for a month with a yield of over 35% (7 kg/m(3) in concentration).
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: Sosaku
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Seigo
authors.initials: S
authors.lastname: Sato
authors.forename: Sukekuni
authors.initials: S
authors.lastname: Mukataka
mesh_terms: D019149:Bioreactors; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000737:chemistry*; D006868:Hydrolysis; D009844:Oligosaccharides / Q000138:chemical synthesis*; D011786:Quality Control
chemical_list: D004800:Enzymes, Immobilized; D009844:Oligosaccharides; D006026:Glycoside Hydrolases; C019868:chitosanase