Role of Laccase and Low Molecular Weight Metabolites fromTrametes versicolorin Dye Decolorization

Abstract

<jats:p>The studies regarding decolorization of dyes by laccase may not only inform about the possible application of this enzyme for environmental purposes, but also may provide important information about its reaction mechanism and the influence of several factors that could be involved. In this paper, decolorization of crystal violet and phenol red was carried out with different fractions of extracellular liquids from<jats:italic>Trametes versicolor</jats:italic>cultures, in order to describe the role of laccase in this reaction. Moreover, the possible role of the low molecular weight metabolites (LMWMs) also produced by the fungus was evaluated. The results confirm the existence of a nonenzymatic decolorization factor, since the nonprotein fraction of the extracellular liquids from cultures of<jats:italic>T. versicolor</jats:italic>has shown decolorization capability. Several experiments were performed in order to identify the main compounds related to this ability, which are probably low molecular weight peroxide compounds.</jats:p>

Physiological Characterization of Fungal Inoculum for Biotechnological Remediation of Soils

“…RBBR de-coloration's kinetics employed to identify the ligninolytic system's total action in the de-coloration of the anthrachinonic colorant showed positive results. The similarity of laccase and RBBR de-coloration enzymatic profile proved the hypothesis that laccase was the main oxidase involved in pentachlorophenol degradation, rendering it an important biotechnological tool, which was also observed by other authors, including in degradation studies (Jeon et al 2008;Moreira Neto et al 2009;Cañas e Camarero 2010;Majeau et al 2010;Niebisch et al 2010;Gaitan et al 2011;Ding et al 2012;Eichlerová et al 2012;Moldes et al 2012;Pardo et al 2012;Ueda et al 2012;Janusz et al 2013;Manavalan et al 2013). Laccase production, with concomitant Mndependent peroxidase production showed that such enzymatic activities might be involved in the in vivo pentachlorophenol degradation under the assessed conditions, since the highest enzymatic activities in the PCP-soil were observed in the treatments with the highest degradation rates.…”

Malachite green decolorization by the filamentous fungus Myrothecium roridum – Mechanistic study and process optimization

“…Peroxides may be responsible for the observed dye oxidation because these compounds have been proven to directly oxidize some chemical structures or promote their oxidation through hydroxyl radicals formed by the Fenton reaction. Several researchers have proposed that Fenton-like reactions are an important nonenzymatic mechanism in dye decolorization (Gomaa et al, 2008;Gomaa, 2012;Karimi et al, 2012;Moldes et al, 2012). In order to verify this hypothesis, decolorization tests with catalase, thiourea and superoxide dismutase (known scavengers of hydroxyl radical and superoxide anion radical) were designed.…”

Physiological Characterization of Fungal Inoculum for Biotechnological Remediation of Soils

“…RBBR de-coloration's kinetics employed to identify the ligninolytic system's total action in the de-coloration of the anthrachinonic colorant showed positive results. The similarity of laccase and RBBR de-coloration enzymatic profile proved the hypothesis that laccase was the main oxidase involved in pentachlorophenol degradation, rendering it an important biotechnological tool, which was also observed by other authors, including in degradation studies (Jeon et al 2008;Moreira Neto et al 2009;Cañas e Camarero 2010;Majeau et al 2010;Niebisch et al 2010;Gaitan et al 2011;Ding et al 2012;Eichlerová et al 2012;Moldes et al 2012;Pardo et al 2012;Ueda et al 2012;Janusz et al 2013;Manavalan et al 2013). Laccase production, with concomitant Mndependent peroxidase production showed that such enzymatic activities might be involved in the in vivo pentachlorophenol degradation under the assessed conditions, since the highest enzymatic activities in the PCP-soil were observed in the treatments with the highest degradation rates.…”