Resumo

SOLIS-OBA, M; BARZANA, E; GARCIA-GARIBAY, M  e  VINIEGRA-GONZALEZ, G. The ABTS^•+ an oxidant agent of different chemical compounds and its recycling process between laccase susbtrate. Rev. Mex. Ing. Quím [online]. 2007, vol.6, n.3, pp.275-281. ISSN 1665-2738.

The commercial enzyme laccase cloned from Myceliophtera termophila and expressed in Aspergillus oryzae was used to produce an active, stable and oxidized form of the chemical mediator ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) in order to test the feasibility of using the monocation ABTS^•+ as a recyclable intermediate for the oxidation of a variety of aromatic chemicals in the absence of the enzyme. It was shown that ABTS^•+, by itself, oxidized, indigo blue, tannic and galic acids, brilliant blue G, Coomassie blue, orange 7 and p-cresol. Oxidation was assessed by important changes in their visible absorption spectra. It was also shown that oxidation of these compounds by a mixture of ABTS and laccase can be done in a cyclic manner, such a way the oxidation rate was 94 times higher for indigo, 17 times for brilliant blue G, 34 times for orange 7 and 5 times higher for p-cresol compared with using the mediator or the laccase alone. Those results show the feasibility of a recycling scheme for the final oxidation of a wide variety of aromatic compounds in which the enzyme is not directly in contact with the compound but through the intermediate ABTS^•+.

Palavras-chave : ABTS; recycling; oxidation; dyes; lacction.