Laccase-catalyzed azodye synthesis

There is an increasing demand of the chemical industry to develop eco-friendly processes. In numerous cases, biocatalysis represents an attractive route towards one-step safe synthesis. In this context, the finding that laccases are able to create azo bonds represents a good potential for the dye industry. This work investigates the properties and biosynthesis of an azodye named LAR1, which stands for Laccase Acid Red 1. LAR1 is made up of two anthraquinonic moieties coupled through an azo bond and demonstrated good dyeing properties on nylon, polyamide and particularly on leather. LAR1 has been shown not to be cytotoxic, mutagenic and ecotoxic. Further investigations aimed at optimizing the process of LAR1 production. Several laccases from bacterial and fungal (ascomycetes and basidiomycetes) origin proved to be useful to produce LAR1 in short reaction times. Whatever the laccase tested, optimal pH for LAR1 synthesis was 4 while the highest rates of oxidation for ABTS were obtained between pH 3 and 4. In our conditions, two isoenzymes from Trametes versicolor have been shown to be the most efficient to transform ABu62. It was also found that oxidation of the anthraquinonic precursor by these laccases did not follow a classica