High Laccase Expression by Trametes versicolor in a Simulated Textile Effluent with Different Carbon Sources and PHs

Abstract

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 U∙L−1) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs.

Potential of ligninolytic enzymatic complex produced by white‐rot fungi from genus Trametes isolated from Bulgarian forest soil

“…Among the tested substances, glycerol and Tween 80 were the best Lac inducers. A similar increase in Lac production in response to the addition of glycerol has been reported about different whiterot fungi [22,53]. Furthermore, Tween 80 and veratryl alcohol significantly improve MnP production by T. trogii in every concentration used in the study.…”

“…Different natural or synthetic agents have been used to induce the synthesis of ligninases [11,13,15,43]. A similar increase in Lac production in response to the addition of glycerol has been reported about different whiterot fungi [22,53]. Among the tested substances, glycerol and Tween 80 were the best Lac inducers.…”

Requalification of a Brazilian Trichoderma Collection and Screening of Its Capability to Decolourise Real Textile Effluent

“…The use of oxidative enzymes, mainly Lac and peroxidases, in textile industry has increased quickly. It has been due to both: (a) the ability of these oxidative enzymes to bleach textiles; and (b) the biological treatments involving these enzymes seem to be an attractive solution mainly because most existing treatments (e.g., coagulation/flocculation, adsorption, ion exchange, and electrochemical methods) of dye wastewater utilize ineffective and uneconomical processes [ 12 ]. In addition, other biomimetic oxidative bleaches, like metalloporphyrins, are very promising catalysts for synthetic textile dyes.…”

Effects of Orange Peel Extract on Laccase Activity and Gene Expression in Trametes versicolor

“…These laccase isoforms can be assumed to be partially responsible for the increased oxidative potential observed for both OPE and veratryl alcohol (Figure 2B). Ottini et al also reported the upregulation of a laccase-encoding gene homologous to LCC3 in T. versicolor MUM 04.100 when cultivated in the presence of alternative carbon sources [51]. The shaken submerged cultures of T. M99 were prepared with 20% OPE or 5 mM veratryl alcohol, added from the start of the experiment.…”