Abstract

PREUSSLER, César A.; SHIMIZU, Ernesto; VILLALBA, Laura L.  and  ZAPATA, Pedro D.. Copper laccase induction in white rot fungi Trametes villosa (Sw.: Fr.) kreisel. Rev. cienc. tecnol. [online]. 2009, n.12, pp.09-16. ISSN 1851-7587.

White rot fungi hold great interest for biotechnological applications being at the same time able to produce extracellular enzymes like laccase. Laccase is a phenoloxidase with molecular weight between 60 and 80 kDa, with gene inducible expression probably reflecting the different physiological functions of the enzyme. The present work was focused on the dye oxidizing capacity of T. villosa BAFC 2755 in solid media (discoloration tests) and the effect of CuSO₄ as inductor on the enzyme secretion capacity and genetic expression in liquid media. Discoloration tests in solid media showed good degrading capacity against bromophenol blue, malachite green and black liquor at low pH. Enzyme activity tests from liquid media confirmed extracellular laccase production induced with CuSO₄. Total secreted proteins showed a significant increase in the presence of CuSO₄. SDS-PAGE showed an increase in the protein fraction between 60 and 70 kDa. mRNA levels showed a clear increase in the presence of the inducer. The results showed that the Cu₂+ produced an increase on laccase activity in Trametes villosa. This rise could be due to an increase in the protein and mRNA.

Keywords : White rot fungi; Trametes villosa; Laccase; Enzyme induction; Copper.

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