Blue and yellow laccases of ligninolytic fungi

Abstract

Extracellular laccases from submerged cultures of Coriolus versicolor BKM F-116, Panus tigrinus 8/18, Phlebia radiata 79 (ATCC 64658), Phlebia tremellosa 77-51 and from cultures of Pa. tigrinus 8/18, Ph. radiata 79 and Agaricus bisporus D-649 grown on wheat straw (solid-state fermentation) were purified. All enzymes from submerged cultures had a blue colour and characteristic absorption and EPR spectra. Laccases from the solid-state cultures were yellow-brown and had no typical blue oxidase spectra and also showed atypical EPR spectra. Comparison of N-terminal amino acid sequences of purified laccases showed high homology between blue and yellow-brown laccase forms. Formation of yellow laccases as a result of binding of lignin-derived molecules by enzyme protein is proposed.

A Novel Laccase with Potent Antiproliferative and HIV-1 Reverse Transcriptase Inhibitory Activities from Mycelia of MushroomCoprinus comatus

“…They can oxidate a variety of phenolic and inorganic compounds, including diphenols, polyphenols, and substituted phenols, using molecular oxygen as the electron acceptor [1, 2]. Although they were first reported and named from plant, laccases are widely distributed in higher plants and fungi and have also been found in insects and bacteria [3].…”

A Laccase of Fomes durissimus MTCC-1173 and Its Role in the Conversion of Methylbenzene to Benzaldehyde

“…Instead, it has a yellow colour. It has already been reported in the literature that some fungal strains, which secrete blue laccase in submerged liquid cultures, secrete blue laccases when grown in solid-state fermentation containing natural lignin substrate, wheat straw [19]. The yellow laccases lack absorption band around 610 nm observed in cases of blue laccases.…”

“…The authors could not detect the blue absorption band around 610 nm in the purified laccase spectrum, indicating that it is a yellow laccase. It has also been reported that yellow laccases which oxidize non-phenolic substrates without the presence of electron transfer mediators [19,20] which are essential for the oxidation of non-phenolic substrates by blue laccases. The purified laccase was tested for its property of the oxidation of veratryl alcohol, a non-phenolic substrate which is not oxidized by blue laccases in the absence of the mediator molecules.…”

“…The special status of the laccase among lignolytic enzymes has prompted the authors to screen this fungus for the secretion of the laccase. In addition, there are reports [19,20] that blue laccase-secreting fungal strains secrete yellow laccases in the presence of culture media containing natural lignin-containing substrates but studies on yellow laccases are rare [21][22][23][24]. Moreover, blue laccases transform methylbenzene to benzaldehyde in the presence of mediator molecules [25,26].…”

Oxidation Catalysis by Enzymes in Microemulsions

“…There is increasing interest in their use to treat textile wastewaters which also contain auxiliary chemicals such as surfactants and salts [84,85]. Environmental pollutants (dioxins, polycyclic aromatic hydrocarbons, chlorophenols) which are some of the substrates of laccases, are not water soluble so the use of microemulsions was unavoidable [86].…”