Browsing by Subject "laccase"

The aims of this study were to use the heterologously expressed laccase in Pichia pastoris as oxidative biocatalysts for the degradation of BPA and to find out natural mediators that could assist this laccase to degrade BPA efficiently and environmental friendly. In addition, removal of the estrogenic activity of BPA by the white rot fungus Physisporinus rivulosus cultures and the role of its laccase 2 in the BPA disapperance was also focused. Firstly, the removal of BPA’s estrogenic activity by the white rot fungus Physisporinus rivulosus was confirmed in cultures both with and without the fungal mycelium. Next, the recombinant laccase 2 (rLac2) played a role in the BPA disapperance. At the similar laccase activity level, removal of BPA’s estrogenic activity was done more efficiently in the fungal cultures than in the cell-free enzymatic treatments. Metabolites present in the fungal cultures could possibly act as natural mediators that enhance the removal of BPA. In addition, combination of nine laccases present in the fungal cultures could possibibly enhance the degradation of BPA. Finally, none of the ten mediatiors used was found to act as an efficient rLac2 enhancer in degrading BPA. Degradation of BPA was followed using a bioreporter system. The yeast Saccharomyces cerevisiae has been genetically modified in order to express the estrogen receptor alpha and produce a bioluminescent signal upon contact with estrogenic substances such as BPA. This bioreporter system has been further developed to specifically detect the estrogenic activity of bisphenol A and to be used in a high-throughput manner.