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Department of Chemical EngineeringLignin peroxidase is promising ingredient for skin whitening cosmetics because it is capable of oxidizing melanin with high redox potential. Crude lignin peroxidase from fungal fermentation is usually utilized owing to its difficulties of expression and purification. Lignin peroxidase is hard to express and purify so it was usually applied as crude form for cosmetics. In this study, lignin peroxidase isozyme H8 (LiPH8) from Phanerochaete chrysosperium was expressed in E. coli and purified for further use of melanin decolorization. The pH optimum for the decolorization of melanin was pH 4.0. Melanin decolorization efficiency was reached to 73% by intermittent addition of hydrogen peroxide (H2O2), since excessive concentration of H2O2 converts LiPH8 into compound III which is the inactivated form of lignin peroxidase. Considering that the intermittent supply of H2O2 is not practical for cosmetic applications, glucose oxidase from aspergillus niger (GOx) was utilized for in-situ generation of H2O2. GOx and ??-D-glucose concentration was optimized and melanin decolorization efficiency reached 63.3% within 1h. LiPH8 retained its activity for 8h with 84.0% of melanin decolorization efficiency. With these results, melanin decolorization catalyzed by LiPH8 with H2O2 generated from GOx was proven to be a prospective approach for skin whitening applications.clos

Embedded minimal and constant mean curvature annulus touching spheres

We show that a compact embedded minimal or constant mean curvature annulus with non-vanishing Gaussian curvature which is tangent to two spheres of same radius or tangent to a sphere and meeting a plane in constant contact angle is rotational.Comment: 10 page