Enhanced production of laccase activity by Trametes versicolor immobilized into alginate beads by the addition of different inducers

Abstract

In the present paper the effect of adding veratryl alcohol and copper sulphate on laccase activity production by Trametes versicolor immobilized into alginate beads has been investigated. Employing copper sulphate as laccase inducer or supplementing the culture medium with veratryl alcohol, led to maximum values of laccase activity. However, the highest laccase activity (around 4,000 U l -1 ) was obtained in cultures simultaneously supplemented with copper sulphate (3 mM) and veratryl alcohol (20 mM). These values implied a considerable enhancement in relation to control cultures without any inducer (around 200 U l -1 ). The production of laccase by immobilized T. versicolor in a 2-l airlift bioreactor with the optimized inducer has been evaluated. Laccase activities around 1,500 U l -1 were attained. The bioreactor operated for 44 days without operational problems and the bioparticles (fungus grows in alginate beads) maintained their shape throughout the fermentation. Moreover, the extracellular liquid obtained was studied in terms of pH and temperature activity and stability. On the other hand, anthracene was added in two-repeated batches in order to determine the efficiency of this process to degrade pollutants. Near complete degradation was reached in both batches. Moreover, in vitro degradation of several polycyclic aromatic hydrocarbons by crude laccase was also performed.

Immobilization of Laccase on Magnetic Carriers and Its Use in Decolorization of Dyes

“…pH optimums for free and immobilized laccase T. versicolor range from pH 3.0 to 5.5. In contrast to our results, immobilization mostly causes pH optimum to move about pH 0.5 higher 11,15,27,28 . Decrease in activity from pH optimum to pH 2.5 and 6.2 is similar as in articles 10,11 .…”

A novel approach for application of white rot fungi in wastewater treatment under non-sterile conditions: immobilization of fungi on sorghum

“…Also, heterotrophic bacteria could simply use the protein laccase as substrate [48], which might be another reason for the decrease in laccase activity in the real wastewater. It is noteworthy that the compounds which are usually used in the defined WRF media to induce laccase activity, such as Cu 2+ [49], Mn 2+ [50] or veratryl alcohol [51], were not used in this study. Although only laccase was assayed as the fungal enzyme in this study, the involvement of other enzymes like MnP should not be neglected.…”

Validation of computationally predicted substrates for laccase

“…Finding of these structural specificities would be important to know the exact mechanism of pesticide degradation by laccase. Structural influence of xenobiotic on the extent of their degradation by laccase was mentioned by Dominguez et al (2007), particularly for PAH structures (anthracene, benzo pyrene, pbenzoquinone and phenanthrene), indicating the specificity of enzyme towards these substrates. Different laccases differ considerably in their catalytic preferences.…”