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Properties of a reversible soluble–insoluble cellulase and its application to repeated hydrolysis of crystalline cellulose
Author(s) -
Taniguchi Masayuki,
Kobayashi Mikio,
Fujii Michihiro
Publication year - 1989
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260340810
Subject(s) - cellulase , chemistry , hydrolysis , cellulose , immobilized enzyme , dissolution , precipitation , chromatography , reducing sugar , enzymatic hydrolysis , enzyme , sugar , organic chemistry , physics , meteorology
Abstract Cellulase was covalently immobilized on an enteric coating polymer, Eudragit L , that is reversibly soluble and insoluble depending on the pH of the medium. The hydrolysis of solid cellulose with the immobilized enzyme can take advantage of the soluble property of the immobilized enzyme itself at the most reactive pH value; on the other hand, recovery of the enzyme can take advantage of the insoluble property of the enzyme at other pH values. It was experimentally confirmed that 100% of immobilized enzyme activity in solution can be recovered by precipitation and by dissolving it again by alternative change of pH. After a period of hydrolysis, immobilized enzyme and unreacted cellulose were precipitated together to remove the product—the soluble sugar solution—by changing pH. Following this, a new buffer solution was added to the precipitate to dissolve it and resume the reaction. This was repeated several times. The hydrolysis rate of this process increased significantly compared with that of a batch process. Utilization of the reversible soluble–insoluble carrier for immobilizing enzyme is promising, not only for cellulose–cellulase systems, but also for other heterogeneous reaction systems.