Increased expression of laccase by the addition of phthalates inPhlebia tremellosa

Abstract

Phthalates, which are used as plasticizers in the plastics industry, are widely used and have been dispersed into the environment. A white-rot basidiomycete Phlebia tremellosa, which showed good growth in media containing various hormone-mimicking compounds, degraded benzylbutylphthalate and diethylphthalate by up to 30% and 80%, respectively, under liquid culture conditions for 9 days. A laccase cDNA from P. tremellosa was cloned by a rapid amplification of cDNA ends (RACE)-PCR technique, and found to encode 1832 nucleotides. Its deduced amino acid sequence showed 80.7% identity when compared with that of Phlebia radiata, and 64.8% identity when compared with that of Trametes versicolor. When this fungus was grown under suitable conditions for degrading phthalic esters, the laccase activity and its transcript level were both highly increased.

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

“…1-3 control culture (no EDC); 4-6, BBP; 7-9, DEP 1-3, no EDC). This was an expected result because laccase expression was detected during the degradation of phthalates in P. tremellosa (Yeo et al 2008). Since increased MnP expression was reported in Trametes versicolor under the EDC degrading conditions (Kim et al 2008b), MnP and/or LiP must also be involved in degrading the EDCs in these transformants.…”

“…We have cloned the laccase cDNA from P. tremellosa and confirmed its enhanced expression under the degrading conditions of phthalates (Yeo et al 2008). We have determined its biochemical characteristics of the purified enzyme as well as the involvement of the enzyme in the removal of estrogenic activity generated by several EDCs (Kim et al 2008a).…”

“…70% growth of control culture). Laccase activity of P. tremellosa was increased up to 26-35 times in the liquid media by addition of phthalates (Yeo et al 2008). Even though two transformants carried the same laccase promoter and gene from P. tremellosa, none of the transformants showed such a high induction; the enzyme activity was increased about twice by the addition of each phthalate, however, they showed 5-6 times higher enzyme activities when compared with the wild type.…”

“…Irpex lacteus isolated in Korea forest (Kim and Song 2003) was grown on potato dextrose agar at 30°C, and a minimal medium (Yeo et al 2008) was also used when needed. Genomic gene (3.1 kb) of a laccase from P. tremellosa was inserted at the BamHI site of pBARGEM7-1 plasmid to construct a laccase expression vector (pBARPprolac), and this vector had the phosphinothricin resistance gene as the selectable marker.…”

Decolorization of a Dye by Immobilized Lignin Degrading Enzymes Generated from Transformants of Merulius tremellosus Fr.

“…리그닌을 분해하는 백색부후균류는 분해 에 필요한 효소를 가지고 있는데, laccase, lignin peroxidase 및 manganese peroxidase 등이 보고되었다. 이 효소들은 기질특이 성이 강하지 않기 때문에 폭약류 (Cheong et al, 2006), 내분비계 장애물질 Yeo et al, 2008)과 다양한 난분해성 물질(Baldrin, 2006)을 분해한다고 보고되었다. 경기도 광릉의 숲에서 분리한 아교버섯은 다양한 내분비계 장애물질을 더한 potato dextrose 한천배지에서 잘 생장하였기 때문에 이 균이 가 지고 있는 리그닌 분해효소들에 대하여 연구를 수행하였다.…”