New pulp biobleaching system involving manganese peroxidase immobilized in a silica support with controlled pore sizes.
Attempts have been made to use manganese peroxidase (MnP) for chlorine-free pulp biobleaching, but they have not been commercially viable because of the enzyme's low stability. We developed a new pulp biobleaching method involving mesoporous material-immobilized manganese peroxidase from Phanerochaete chrysosporium. MnP immobilized in FSM-16, a folded-sheet mesoporous material whose pore size is nearly the same as the diameter of the enzyme, had the highest thermal stability and tolerance to H(2)O(2). MnP immobilized in FSM-16 retained more than 80% of its initial activity even after 10 days of continuous reaction. We constructed a thermally discontinuous two-stage reactor system, in which the enzyme (39 degrees C) and pulp-bleaching (70 degrees C) reactions were performed separately. When the treatment of pulp with MnP by means of the two-stage reactor system and alkaline extraction was repeated seven times, the brightness of the pulp increased to about 88% within 7 h after completion of the last treatment.
Sasaki
T
T
Toyota Central R&D Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192, Japan.
Kajino
T
T
Li
B
B
Sugiyama
H
H
Takahashi
H
H
D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006861:Hydrogen Peroxide; D010544:Peroxidases / Q000378:metabolism*; D020075:Phanerochaete / Q000201:enzymology*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D014934:Wood
D004800:Enzymes, Immobilized; D058428:Silica Gel; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide; D010544:Peroxidases; C051129:manganese peroxidase