Atividade de lacase e descoloração de corantes industriais por extrato enzimático de Leiotrametes menziesii (BERK.) WELTI & COURTEC. cultivado em meio líquido e em casca de tucumã.

Abstract

White rot fungi are wood-decomposing organisms that synthesize a range of enzymes with potential applications in biotechnological and industrial processes. These enzymes can be employed in the bioremediation of effluents contaminated with industrial dyes. Laccase is one of the enzymes synthesized by these organisms, which plays a role in degrading lignin, a recalcitrant substance that provides rigidity to plant fibers. The aim of the present study was to determine laccase activity and the capacity to decolorize industrial dyes using an enzymatic extract from Leiotrametes menziesii cultivated in liquid medium and tucumã husks. Six dyes were utilized: Acid Red 1, Remazol Brilliant Blue R, Acid Blue 129, Reactive Blue 4, Reactive Black 5, and Malachite Green. Qualitative tests with guaiacol and tannic acid confirmed the presence of phenoloxidases. Laccase activity was determined in liquid medium after 14 days of cultivation, reaching 762.92 U/L at pH 2.5. The extract was able to degrade all dyes except Acid Red 1. In the second stage of the study, the isolate was cultivated in tucumã husks, and the extract was used to determine laccase activity and decolorization assays at pH 2.5. No laccase activity was detected in the enzymatic extract, and it also failed to cause decolorization, suggesting that there may be a correlation between laccase activity and the degradation of these substances.