Degradation of Orange G by Laccase: Fungal Versus Enzymatic Process

Abstract

Biodegradation of the Orange G azo dye by pellets of Trametes versicolor in a fluidized bioreactor operating under conditions of laccase production was studied. The percentage of decolorization obtained was 97% in batch mode and both the biomass and the broth, were colorless. In vitro degradations carried out with purified commercial laccase from Trametes versicolor demonstrated that laccase is able to degrade the dye. In spite of the high level of decolorization reached in both processes, an important difference between the fungal and enzymatic treatments was detected. At the end of the experiments carried out in vitro, a final residual color appears (different to the initial one). Consequently, measuring the yield of decolorization as a percentage of absorbance lambdamax variation is not the best indicator of the treated wastewater quality, but the analysis of the visible color spectrum makes it possible to detect changes in color. The results demonstrate that better results are obtained with fungal Orange G biodegradation because a further breakdown of the enzymatic products is achieved with the fungus.

Biodegradation Characteristics of Pharmaceutical Substances by Whole Fungal Culture Trametes versicolor and its Laccase

“…As a result, higher removal efficiency was observed for most selected PhACs in the presence of redox mediators (ABTS or HBT) compared with those in the absence of mediators. The degradation tendency observed in this study is relatively consistent with those reported in the literature (Rodríguez et al, 2004;Tamagawa et al, 2005;Maruyama et al, 2006;Auriol et al, 2007;Canas et al, 2007;Casas et al, 2007), wherein they found that fungal laccase can oxidize a variety of organic compounds in the presence of a redox mediator, such as HBT or ABTS. However, the degradation spectrum in the presence of redox mediators was still mainly dependent on the characteristics of target compounds.…”

Bioremoval of the synthetic dye malachite green by marine Trichoderma sp

“…Degradation of these compounds in azo dyes is a challenge in current research. Microbial enzymes are capable of removing phenolics and aromatic amines present in the azo dyes (Claus 2003; Casas et al 2007). The enzyme laccase, has enormous biotechnological applications such as in paper pulp bleaching, decolorization of synthetic dyes, wine clarification, fruit juice processing, bioremediation, ethanol production, biosensors, biofuel cells, organic synthesis and drug synthesis (Mayer and Staples 2002; Hadzhiyska et al 2006; Zhu et al 2011).…”

Fungal Decolourization and Degradation of Synthetic Dyes Some Chemical Engineering Aspects

“…The obtained percentage of decolourization was 97% in only 20 h. As high as 3500 AU/L of laccase was determined, while no MnP activity was detected. Better results were obtained this way compared to In Vitro experiments with commercial purified laccase from T. versicolour (Casas et al, 2007). The batch and continuous operation mode of a 1.5-L bubble column bioreactor were used for the cultivation of T. versicolour in the pellet form and degradation of Grey Lanaset G metalcomplex dye.…”

“…Selected references from the last decade for laboratory reactors with volumes larger than 1.0 L are briefly presented below. Libra, 2003Leidig, 1999Casas, 2007Blanquez, 2004Zhang, 1999Tavčar, 2006Ge, 2004Tavčar, 2006Trošt, 2010 Yang, 2009 Hai, 2008Gao, 2009 Table 5. Fungal bioreactors for degradation and decolourization of dyes…”