Enzymatic Oxidative Transformation of Chlorophenol Mixtures

Abstract

Chlorinated phenols are major industrial and agricultural xenobiotics that pollute soil and ground water. It has been shown that laccases catalyze the oxidative coupling of phenolic compounds. Therefore, the transformation of one or a mixture of several chlorinated phenols by a laccase from the fungus Trametes villosa was studied. Generally, if more than one phenol was added, the transformation of chlorinated phenols decreased, and if the concentration of the laccase was increased, the transformation of the phenols was enhanced. There were exceptions to these observations: for instance, the transformation of 0.1 mM 4-chlorophenol incubated with 1 mM 2,4-dichlorophenol in buffered salt solutions was not enhanced if the concentration of the laccase was increased from 2 to 20 DMP units/mL. The reason for the reduced transformation of chlorinated phenols in the presence of additional phenols is still unknown. However, in spite of some limitations, the application of laccase to decontaminate wastewater polluted with chlorinated phenols appears feasible.

Kinetic study of phenol hydroxylase and catechol 1,2-dioxygenase biosynthesis by Candida tropicalis cells grown on different phenolic substrates

“…Phenols and chlorophenols are aromatic compounds of serious environmental concern because of their widespread use, toxicity for aquatic species, and occurrence throughout the environment (Katayama-Hirayama et al 1994;Reineke 1998;Bollag et al 2003). The chlorinated phenols are more toxic than the unsubstituted compound.…”

Sorption Behavior of 4-Chlorophenol from Aqueous Solutions By a Surfactant-modified Mexican Zeolitic Rock in Batch and Fixed Bed Systems

“…Additionally, wastewaters from industries such as polymeric resin production, oil refining and coking plants also contain chlorophenols (Bollag, Chu, Rao, & Gianfreda, 2003).…”

“…Currently, many physical and chemical methods are available for decontaminating chlorinated phenols (Bollag, Chu, Rao, & Gianfreda, 2003). Many methods including sorption and biological degradation, chemical oxidation, and solvent extraction have been used for this purpose.…”

Evidence for the importance of litter as a co-substrate for MCPA dissipation in an agricultural soil

“…Fungi have been described to degrade xenobiotics by cometabolism rather than using xenobiotics as sole carbon source (Bennett et al 2001). Several studies have demonstrated the ability of fungi to degrade 2,4-D and MCPA, and in most cases, lignin-degrading enzymes have been implicated (Bollag et al 2003;Sedarati et al 2003;Singleton 2001;Vroumsia et al 1999). Kalbitz et al (2003) found an enrichment of lignin-derived aromatic compounds in dissolved organic carbon (DOC) originating from biodegradation of maize straw and other plant residues.…”