Recombinant lignin peroxidase-catalyzed decolorization of melanin using in-situ generated H2O2 for application in whitening cosmetics

Lignin peroxidase has high potential as ingredient in skin whitening cosmetics due to its high redox potential to oxidize recalcitrant melanin. Currently crude mixtures of lignin peroxidase from fungal fermentation are usually applied to cosmetics due to the intrinsic difficulties of expression and purification. However, the present study focused on heterologous expression and purification of lignin peroxidase isozyme H8 (LiPH8) from Phanerochaete chrysosporium and was further used for melanin decolorization. Results revealed that the optimum pH for melanin decolorization using LiPH8 was obtained at pH 4.0. The intermittent feeding of hydrogen peroxide (H2O2) was effectively elevating melanin decolorization efficiency up to 73%, since excessive H2O2 inactivated LiPH8. For cosmetic application, intermittent feeding of H2O2 is not feasible, thus glucose oxidase (GOx) from Aspergillus niger was employed for in-situ generation of H2O2. By optimizing the GOx and glucose concentrations, a melanin decolorization efficiency up to 63.3 ± 2.4% was obtained within 1 h and continued to 84.0 ± 1.8% in 8 h. Conclusively, lignin peroxidase-catalyzed decolorization of melanin with in-situ generated H2O2 revealed a promising approach for whitening cosmetics applications.