Purification and characterization of a melanin biodegradation enzyme from Geotrichum sp.

ObjectiveMelanin is a black or brown phenolic polymer present mainly in skin and hair. Although melanin can be degraded by some microbial species, the melanin degradation capacity of Geotrichum sp. is unknown. The aim of this study was to characterize a melanin biodegradation enzyme from Geotrichum sp. MethodsIn this study, we assessed the melanin degradation activity of Geotrichum sp. in comparison with the major melanin-degrading enzymes, manganese-dependent peroxidase (MnP), manganese-independent peroxidase, lignin peroxidase and laccase. Furthermore, the effect of several carbohydrates on melanin degradation by Geotrichum sp. was determined. The MnP enzyme was purified using ammonium sulphate precipitation and Sephadex G-200 column chromatography, and then the conditions for optimal enzymatic activity were determined by adjusting the pH, temperature and Tween-80 concentration. ResultsCompared with extracellular ligninolytic enzymes of Geotrichum sp., MnP had the highest ligninolytic enzyme activity; and the highest enzymatic activity was observed in the presence of glucose. The final purified MnP enzyme exhibited 6 U mL(-1) activity and had a molecular weight of 54.2 kDa. The enzymatic activity was highest at pH 4.5 and 25-35 degrees C in the absence of Tween-80. ConclusionThese results indicate the potential of MnP purified from Geotrichum sp. as a skin-lightening agent in the cosmetic industry. Resume ObjectifLa melanine est un polymere phenolique noir ou brun, presente principalement dans la peau et les cheveux. Bien que la melanine puisse etre degradee par certaines especes microbiennes, la capacite de degradation de la melanine de Geotrichum sp. est inconnue. Le but de cette etude etait de caracteriser une enzyme de biodegradation de la melanine de Geotrichum sp. MethodesDans la presente etude, nous avons evalue l'activite de degradation de la melanine de Geotrichum sp. en comparaison avec les principales enzymes de degradation de la melanine, le manganese peroxydase Mn-dependante (MnP), la peroxydase non-manganese dependante, la lignine-peroxydase et une laccase. En outre, l'effet de plusieurs carbohydrates sur la degradation de la melanine par Geotrichum sp. etait determine. L'enzyme MnP a ete purifiee par precipitation au sulfate d'ammonium et chromatographie sur une colonne de Sephadex G-200, puis les conditions d'une activite enzymatique optimale ont ete determinees en ajustant le pH, la temperature et la concentration de Tween-80. ResultatsPar rapport aux enzymes ligninolytiques extracellulaires de Geotrichum sp, MnP a eu l'activite enzymatique lignolytique la plus elevee; et l'activite enzymatique la plus elevee a ete observee en presence de glucose. L'enzyme finale purifiee MnP presentait 6 U mL(-1) d'activite et possede un poids moleculaire de 54.2 kDa. L'activite enzymatique etait la plus elevee a un pH de 4.5 et de 25 a 35 degrees C en l'absence de Tween-80. ConclusionCes resultats indiquent le potentiel de MnP purifiee a partir de Geotrichum sp. en tant qu'agent eclaircissant la peau dans l'industrie cosmetique.