White-rot fungi (WRF) and their ligninolytic enzymes (laccases and peroxidases) are considered promising biotechnological tools to remove lignin related Persistent Organic Pollutants from industrial wastewaters and contaminated ecosystems. A high diversity of the genus Ganoderma has been reported in Cuba; in spite of this, the diversity of ligninolytic enzymes and their genes remained unexplored. In this study, 13 native WRF strains were isolated from decayed wood in urban ecosystems in Havana (Cuba). All strains were identified as Ganoderma sp. using a multiplex polymerase chain reaction (PCR)-method based on ITS sequences. All Ganoderma sp. strains produced laccase enzymes at higher levels than non-specific peroxidases. Native-PAGE of extracellular enzymatic extracts revealed a high diversity of laccase isozymes patterns between the strains, suggesting the presence of different amino acid sequences in the laccase enzymes produced by these Ganoderma strains. We determined the diversity of genes encoding laccases and peroxidases using a PCR and cloning approach with basidiomycete-specific primers. Between two and five laccase genes were detected in each strain. In contrast, only one gene encoding manganese peroxidase or versatile peroxidase was detected in each strain. The translated laccases and peroxidases amino acid sequences have not been described before. Extracellular crude enzymatic extracts produced by the Ganoderma UH strains, were able to degrade model chromophoric compounds such as anthraquinone and azo dyes. These findings hold promises for the development of a practical application for the treatment of textile industry wastewaters and also for bioremediation of polluted ecosystems by well-adapted native WRF strains.

Our novel strategy for the rational design of immobilized derivatives (RDID) is directed to predict the behavior of the protein immobilized derivative before its synthesis, by the usage of mathematic algorithms and bioinformatics tools. However, this approach needs to be validated for each target enzyme. The objective of this work was to validate the RDID strategy for covalent immobilization of the enzyme laccase from Trametes maxima MUCL 44155 on glyoxyl‐ and monoaminoethyl‐N‐aminoethyl (MANA)‐Sepharose CL 4B supports. Protein surface clusters, more probable configurations of the protein–supports systems at immobilization pHs, immobilized enzyme activity, and protein load were predicted by RDID1.0 software. Afterward, immobilization was performed and predictions were experimentally confirmed. As a result, the laccase‐MANA‐Sepharose CL 4B immobilized derivative is better than laccase‐glyoxyl‐Sepharose CL 4B in predicted immobilized derivative activity (63.6% vs. 29.5%). Activity prediction was confirmed by an experimentally expressed enzymatic activity of 68%, using 2,6‐dimethoxyphenol as substrate. Experimental maximum protein load matches the estimated value (11.2 ± 1.3 vs. 12.1 protein mg/support mL). The laccase‐MANA‐Sepharose CL 4B biocatalyst has a high specificity for the acid blue 62 colorant. The results obtained in this work suggest the possibility of using this biocatalyst for wastewater treatment.

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White-rot fungi are considered to be promising biotechnological tools to complement or replace the current technologies for the treatment of effluents from textile production plants. The aim of this work was to investigate the decolorization capacity of Ganoderma weberianum B-18 in solid state fermentation with sugarcane bagasse as a substrate and ligninolytic inducer as well as to decolorize and detoxify industrial effluents by this strain in a laboratory scale packed-bed bio-reactor. The results demonstrated that Ganoderma weberianum B-18 indeed showed to possess decolorization capacity in solid state fermentation with sugarcane bagasse supplemented with synthetic dyes. Moreover, fungal biomass of G. weberianum B-18 immobilized in sugarcane bagasse in a packed-bed bioreactor was shown to efficiently decolorize and detoxify different dyes and authentic industrial effluents in semi-continuous conditions. In this decolorization process, laccase enzymes secreted by the fungus played the main role. Hence, a packed-bed reactor with G. weberianum B-18 immobilized in sugarcane bagasse seems to be a suitable system for the further development of an efficient bioprocess for large-scale treatment of dye-containing wastewaters.

Three strains of white-rot fungi were tested in solid state fermentation and submerged culture to obtain enzymes for dyes biotransformation. Both sugarcane bagasse and dyes induced laccase and manganese peroxidase biosynthesis but laccase seems to be the main enzyme related to the decolourisation profiles. A variable behavior of strains was observed depending on inducers, fermentation system and characteristics of the strains. Crude enzyme of Earliella scabrosa obtained in solid state fermentation showed higher decolourisation percentage of Navy FNB and Red FN-3G dyes than Trametes maxima (13) and Ganoderma zonatum (B-18). T. maxima exhibited the best decolourisation percentage in submerged cultures supplemented with Navy FNB, Red FN-3G and yellow P-6GS dyes. Growing biomass of T. maxima could supply other enzymes and mediators for dyes transformation. Peculiar behaviour was observed with Ganoderma zonatum (B-18), it had a similar dyes biodegradation in both liquid and solid bed fermentation and there was not positive correlation between ligninolytic enzymes production and decolourisation pattern. The employment of crude enzymes produced in solid bed of bagasse could be an attractive option for biological removal of textile dyes.