Laccases—Versatile Enzymes Used to Reduce Environmental Pollution

Abstract

The accumulation of waste and toxic compounds has become increasingly harmful to the environment and human health. In this context, the use of laccases has become a focus of interest, due to the properties of these versatile enzymes: low substrate specificity, and water formation as a non-toxic end product. Thus, we begin our study with a general overview of the importance of laccase for the environment and industry, starting with the sources of laccases (plant, bacterial and fungal laccases), the structure and mechanism of laccases, microbial biosynthesis, and the immobilization of laccases. Then, we continue with an overview of agro-waste treatment by laccases wherein we observe the importance of laccases for the biodisponibilization of substrates and the biodegradation of agro-industrial byproducts; we then show some aspects regarding the degradation of xenobiotic compounds, dyes, and pharmaceutical products. The objective of this research is to emphasize and fully investigate the effects of laccase action on the decomposition of lignocellulosic materials and on the removal of harmful compounds from soil and water, in order to provide a sustainable solution to reducing environmental pollution.

Biochemical Characteristics of Laccases and their Practical Application in the Removal of Xenobiotics from Waters

“…The range of substrates amenable to catalyzed reactions can be extended by mediators [82,[183][184][185][186]. The range of oxidized substrates varies from laccase to laccase [6,187,188].…”

“…Laccases produced by various groups of microorganisms are capable of oxidizing ortho-and paradiphenols, aminophenols, polyphenols, polyamines, lignins, aryldiamines and some inorganic ions [65,187,243,256]. In addition to oxidizing phenolic and methoxyphenolic acids, laccases also attack their carboxyl (decarboxylation) and methoxy (demethylation) groups.…”

Surface characterization of pulp fiber from mixed old newspaper and magazine deinked-pulp with combined cellulase and laccase-violuric acid system (LVS)

“…Laccases have been used in many domains, such as pulp deligni cation and deinking. The attraction to use them has increased dramatically, for deinking secondary bers in the last few years (Valls and Roncero, 2009;Paraschiv et al, 2022). Several kinds of research have been conducted in deinking recycled bers using laccase or laccase mediator system (LMS).…”

“…Several kinds of research have been conducted in deinking recycled bers using laccase or laccase mediator system (LMS). Also, use of laccase alone or in combination with cellulase or hemicellulase is recommended to deink recycled bers (Ibara et al, 2012;Paraschiv et al, 2022). This group of enzymes, in the presence of mediators, can be applied to delignify and bleach processes for different kinds of pulp (Kapoor et al, 2007;Ibara et al, 2012).…”

Laccase–mediator co-immobilized doped-HKUST-1 cellulose composite beads and their application for the biodegradation of carbazole

“…6 Enzyme biocatalysts have gained attention and have been extensively used in biocatalytic reactions, showing unique advantages in terms of efficiency and sustainability of wastewater treatment, as well as substantial developments in fine chemistry and industrial synthesis. 7,8 Laccase (EC 1.10.3.2) belongs to the group of copper-containing polyphenol oxidases, which can efficiently catalyze a wide range of aromatic organic compounds, and thus studies on laccase have been conducted in various fields such as dye decolorization, environmental pollutant degradation, and biomedicine. 9 The laccase catalytic reaction mechanism is based on the synergistic effect of the four Cu ions in its molecular structure and the generation of substrate radicals in the reaction system.…”