Novel laccase-like multicopper oxidases from the Myrothecium roridum fungus - production enhancement, identification and application in the dye removal process

摘要

The aim of this study was to overproduce, identify andapply novel laccase-like multicopper oxidases (LMCOs)from Myrothecium roridum in a dye removal process.LMCOs’ production was enhanced by modifying the mediumand adding copper ions. After purification, twoproteins, LMCO1 and LMCO2, with molecular masses of46.7 and 66.3 kDa were discovered. Peptide analysis bymass spectrometry revealed that they belong to the cupredoxinsuperfamily. Characteristic peptide sequenceswere obtained for MCOs and bilirubin oxidases. Crudeenzymes were applied in a dye decolorization process.Supplementation with 1 mM of vanillin allowed an almostcomplete elimination of the Indigo carmine within3 hours. The dye was removed from a solution containingmetals, surfactants and organic solvents. The in-gelassessment of the activity and decolorization ability ofMCOs, followed by protein extraction and SDS-PAGE,confirmed that only LMCO2 was responsible for the dyeremoval. MCOs produced by Myrothecium sp. have beenpoorly studied before. The obtained results broadenknowledge on this subject and may contribute to the developmentof an eco-friendly method of dye elimination.