TY - JOUR
T1 - Oxidation of bisphenol A catalyzed by laccase hosted in reversed micelles in organic media
AU - Okazaki, Shin Ya
AU - Michizoe, Junji
AU - Goto, Masahiro
AU - Furusaki, Shintaro
AU - Wariishi, Hiroyuki
AU - Tanaka, Hiroo
N1 - Funding Information:
We are grateful to Mercian Co., Ltd. for generously providing the laccase. This research was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) and the Proposal-Based New Industry Creative Type Technology R&D Promotion Program from the New Energy and Industrial Technology Development Organization (NEDO) of Japan. S.O. was supported by research fellowships of JSPS for young scientists.
PY - 2002/8/2
Y1 - 2002/8/2
N2 - The oxidation of bisphenol A [BPA: 2,2-bis(4-hydroxyphenyl)propane] catalyzed in organic solvents by laccase (polyphenoloxidase, EC 1.10.3.2) entrapped in a reversed micellar (RM) system was investigated. The laccase/RM system effectively catalyzed the oxidation reaction in isooctane, while laccase, lyophilized from an aqueous buffer solution in which its activity was optimized, exhibited no catalytic activity in nonaqueous media. To optimize the preparation and reaction conditions for the laccase/RM system, we examined the effects of pH in the water pools of RM, the concentration of laccase, and the degree of surfactant hydration (Wo) on the laccase activity in organic media. The laccase/RM system showed a strong pH-dependency in organic media. Its optimum activity was obtained when the laccase/RM was prepared at pH=5. Interestingly, native laccase in an aqueous buffer solution exhibited an optimal activity at pH=3. The effect of a cosolubilized mediator (1-hydroxybenzotriazole, HBT) on the reaction was also investigated. BPA was effectively oxidized by the laccase/RM system in the absence of a mediator. On the other hand, the addition of 1-hydroxybenzotriazole strongly enhanced the catalytic performance of the laccase/RM system against the oxidation of various chlorophenols in organic media.
AB - The oxidation of bisphenol A [BPA: 2,2-bis(4-hydroxyphenyl)propane] catalyzed in organic solvents by laccase (polyphenoloxidase, EC 1.10.3.2) entrapped in a reversed micellar (RM) system was investigated. The laccase/RM system effectively catalyzed the oxidation reaction in isooctane, while laccase, lyophilized from an aqueous buffer solution in which its activity was optimized, exhibited no catalytic activity in nonaqueous media. To optimize the preparation and reaction conditions for the laccase/RM system, we examined the effects of pH in the water pools of RM, the concentration of laccase, and the degree of surfactant hydration (Wo) on the laccase activity in organic media. The laccase/RM system showed a strong pH-dependency in organic media. Its optimum activity was obtained when the laccase/RM was prepared at pH=5. Interestingly, native laccase in an aqueous buffer solution exhibited an optimal activity at pH=3. The effect of a cosolubilized mediator (1-hydroxybenzotriazole, HBT) on the reaction was also investigated. BPA was effectively oxidized by the laccase/RM system in the absence of a mediator. On the other hand, the addition of 1-hydroxybenzotriazole strongly enhanced the catalytic performance of the laccase/RM system against the oxidation of various chlorophenols in organic media.
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U2 - 10.1016/S0141-0229(02)00104-7
DO - 10.1016/S0141-0229(02)00104-7
M3 - Article
AN - SCOPUS:0037008456
SN - 0141-0229
VL - 31
SP - 227
EP - 232
JO - Enzyme and Microbial Technology
JF - Enzyme and Microbial Technology
IS - 3
ER -