Decolorization of Azo, Triphenylmethane and Anthraquinone Dyes by Laccase of a Newly Isolated Armillaria sp. F022

Abstract

A newly isolated white-rot fungus, Armillaria sp. strain F022, was isolated from the decayed wood in a tropical rain forest. Strain F022 was capable of decolorizing a variety of synthetic dyes, including azo, triphenylmethane, and anthraquinone dyes, with an optimal efficiency of decolorization obtained when dyes added after 96 h of culture, with the exception of Brilliant Green. All of the tested dyes were decolorized by the purified laccase in the absence of any redox mediators, but only a few were completely removed, while others were not completely removed even when decolorization time was increased. The laccase, with possible contributions from unknown enzymes, played a role in the decolorization process carried out by Armillaria sp. F022 cultures, and this biosorption contributed a negligible part to the decolorization by cultures. The effect of dye to fungal growth was also investigated. When dyes were added at 0 h of culture, the maximum dry mycelium weight (DMW) values in the medium containing Brilliant Green were 1/6 of that achieved by the control group. For other dyes, the DMW was similar with control. The toxic tolerance of dye for the cell beads was excellent at least up to a concentration of 500 mg/l. The optimum conditions for decolorization of three synthetic dyes are at pH 4 and 40°C.

Biosorption and biotransformation of fluoranthene by the white‐rot fungus Pleurotus eryngii F032

“…More than 75% fluoranthene degradation was achieved at pH 3–4 of the culture medium, whereas the degradation rate significantly declined when the pH was 5–6. These results are entirely consistent with the findings of a previous study that pH 3–4 is preferable for the growth of white‐rot fungi . Under acidic conditions, the biosorption efficiency was low because an insufficient number of protons competed with fluoranthene to form bonds with functional groups on the cell surface.…”

Cloning and characterization of CotA laccase from Bacillus subtilis WD23 decoloring dyes

“…S133 (Hadibarata et al 2012a), Armillaria sp. F022 (Hadibarata et al 2012b), Trametes sp. SQ01 (Yang et al 2009) and F. fomentarius (Neifar et al 2010).…”

Development of bioreactor systems for decolorization of Reactive Green 19 using white rot fungus

“…Subsequently, the aromatic ring is cleaved. The rate of this step depends on the identity of the ring substituents and the presence of phenolic, amino, acetamido, 2-methoxyphenol, or other easily biodegradable functional groups [22]. Degradation of an azo dye Reactive Black 5 was initiated with cleavage of the azo bond by laccase.…”