Laccase-Mediated Oxidative Degradation of the Herbicide Dymron

Abstract

The present study reports the successful and effective degradation of the persistent herbicide dymron catalyzed by the oxidative enzyme laccase in the presence of a reaction mediator (a laccase/mediator system). Using 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the mediator, over 90% of dymron was degraded within 24 h, while the half-life of dymron is 50 days in soil. The results suggested that oxidation of dymron resulted in the production of decomposed compounds with a single aromatic ring. We also found that edible surfactants and a dishwashing detergent were useful to solubilize dymron in an aqueous solution and did not inhibit the oxidative degradation. Degradation proceeded at acidic pH and in a broad range of temperatures (303-353 K). The use of natural mediators also allowed the oxidative degradation of dymron to some extent. In conclusion, we propose the possible use of a laccase/mediator system for the treatment of soils and drainwater contaminated with herbicides.

Biodegradation Characteristics of Pharmaceutical Substances by Whole Fungal Culture Trametes versicolor and its Laccase

“…In recent years, there has been a growing interest in the study of enzyme activities in wastewater treatment, especially those of the oxidoreductase enzymes from white-rot fungi, such as lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac), due to their recognized potential for oxidizing recalcitrant environmental pollutants, such as dyes (Asgher et al, 2008;Faraco et al, 2009), endocrine disrupting chemicals (Cabana et al, 2007;Cajthaml et al, 2009), herbicides (Maruyama et al, 2006), aromatic hydrocarbons (Canas et al, 2007;Cambria et al, 2008), and antibiotics (Wen et al, 2009). These ligninolytic enzymes are relatively non-specific and use free radical mechanisms to catalyze the degradation of a wide spectrum of organic pollutants (Blánquez et al, 2004;Rodríguez et al, 2004;Cabana et al, 2007;Cajthaml et al, 2009;Wen et al, 2009).…”

Fungal Bioremediation of Emerging Micropollutants in Municipal Wastewaters

“…This phenomenon was true for very recalcitrant compounds as the herbicide dymron (Maruyama et al 2006) and halogenated pesticides (Torres-Duarte et al 2009). …”

“…The presence of ABTS enhanced transformation of dymron (Maruyama et al 2006), TCS (Kim and Nicell 2006a), sulfonamide 14 antibiotics (Weng et al 2013), BPA Nicell 2006b, Macellaro et al 2014) and parabens analogues (Macellaro et al 2014). On the other side HBT was found to be fundamental during laccase treatments of carbamazepine , iso-butylparaben and n-butylparaben (Mizuno et al 2009), anti-inflammatories and estrogens (Lloret et al 2010) and tetracycline antibiotics (Suda et al 2012).…”

“…Laccase-catalyzed system was studied over a pH range 5-9 and set at 6 for natural estrogens (estrone, 17β-estradiol and estriol) and synthetic estrogen (17α-ethinylestradiol) (Auriol et al 2007). The optimal pH range of 4-6 was observed for the transformation of dymron (Maruyama et al 2006), TCS Nicell 2006a, Margot et al 2013), sulfonamide antibiotics (Weng et al 2013), anti-inflammatory pharmaceuticals (Margot et al 2013) and BPA Nicell 2006b, Margot et al 2013).…”

“…As an example, the best working temperature for laccases of Trametes sp. was 70°C, which sharply decreased of 5-fold at 30°C (Maruyama et al 2006). New industrial scenario where fungal thermotolerant laccases could be exploited arises, but it should be carefully taken into consideration the WTP localization and working temperature along the plant.…”