Degradation of endocrine disrupting chemicals by genetic transformants in Irpex lacteus with an inducible laccase gene of Phlebia tremellosa

Abstract

Irpex lacteus was genetically transformed using an laccase expression vector to get increased laccase producing strains. Stable integration of the vector was confirmed by PCR using the vector-specific primers, and the transformants showed increased laccase activities. When the transformants were grown with several endocrine disrupting chemicals, laccase activity of each transformant was induced up to six times higher than that of the wild type. They showed increased degrading activities against EDCs as well as increased removal rates of estrogenic activities generated by the EDCs than the wild type, and the laccase expression was increased during the degradations of the EDCs.

Fungal Bioremediation of Emerging Micropollutants in Municipal Wastewaters

“…For instance, effective laccases of Phlebia tremellosa were overproduced by genetic transformation in Irpex lacteus. The much higher laccase expression led to faster and wider conversion of some EDCs such as BPA, nonylphenol (NP) and two phthalates derivate (Kum et al 2009). …”

Degradation of endocrine disrupting chemicals by genetic transformants with two lignin degrading enzymes in Phlebia tremellosa

“…A genetic transformant using the laccase expression vector showed about 2-fold increase in laccase activity, and also showed 10-600% faster degradation of 4 different EDCs (Yeo et al, 2008b). Another two genetic transformants with the MnP expression vector also showed increased enzyme activity and higher degrading ability to 3 different EDCs (Kum et al, 2009). In order to obtain fungal strains with increased degrading abilities, we attempted to construct a recombinant expression vector for two lignin degrading enzymes, laccase and manganese peroxidase.…”

“…In order to obtain fungal strains with increased degrading abilities, we attempted to construct a recombinant expression vector for two lignin degrading enzymes, laccase and manganese peroxidase. We used laccase genomic DNA from P. tremellosa (Kum et al, 2009) and MnP cDNA from Polyporus brumalis for the construction of the expression vector. We then generated transformants to get fungal strains showing increased degrading ability against two EDCs.…”

“…A laccase genomic DNA used previously in the generation of a transformant of Irpex lacteus (Kum et al, 2009) was used in this study. MnP cDNA was isolated from P. brumalis by RACE (rapid amplification of cDNA ends)-PCR.…”

“…EDCs such as bisphenol A (BPA, 100 mg/L) and nonylphenol (20 mg/L) were added in the minimal medium, and the culture was grown with shaking (160 rpm) at 30°C. The residual concentrations of EDCs were determined as reported previously (Kum et al, 2009). The determination of estrogenic activity was performed using yeast two-hybrid system which had been reported by Tsutsumi et al (2001).…”