Degradation of an endocrine disrupting chemical, DEHP [di-(2-ethylhexyl)-phthalate], by Fusarium oxysporum f. sp. pisi cutinase.
The efficiency of two lypolytic enzymes (fungal cutinase, yeast esterase) in the degradation of di-(2-ethylhexyl)-phthalate (DEHP) was investigated. The DEHP-degradation rate of fungal cutinase was surprisingly high, i.e. almost 70% of the initial DEHP (500 mg/l) was decomposed within 2.5 h and nearly 50% of the degraded DEHP disappeared within the initial 15 min. With the yeast esterase, despite the same concentration, more than 85% of the DEHP remained even after 3 days of treatment. During the enzymatic degradation of DEHP, several DEHP-derived compounds were detected and time-course changes in composition were also monitored. During degradation with fungal cutinase, most DEHP was converted into 1,3-isobenzofurandione (IBF) by diester hydrolysis. In the degradation by yeast esterase, two organic chemicals were produced from DEHP: IBF and an unidentified compound (X). The final chemical composition after 3 days was significantly dependent on the enzyme used. Fungal cutinase produced IBF as a major degradation compound. However, in the DEHP degradation by yeast esterase, compound X was produced in abundance in addition to IBF. The toxic effects of the final degradation products were investigated, using various recombinant bioluminescent bacteria and, as a result, the degradation products from yeast esterase were shown to contain a toxic hazard, causing oxidative stress and damage to protein synthesis.
Department of Chemical and Biological Engineering, Korea University, 1,5-Ka, Anam-Dong, Sungbuk-Ku, 136-701 Seoul, South Korea.
Y-H
YH
Kim
J
J
Lee
S-H
SH
Moon
D002175:Candida / Q000201:enzymology / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D004051:Diethylhexyl Phthalate / Q000378:metabolism*; D004950:Esterases / Q000378:metabolism; D004965:Estrogen Antagonists / Q000378:metabolism*; D005663:Furans / Q000378:metabolism; D005670:Fusarium / Q000201:enzymology* / Q000378:metabolism
D004965:Estrogen Antagonists; D005663:Furans; D004051:Diethylhexyl Phthalate; D004950:Esterases; D002265:Carboxylic Ester Hydrolases; C019952:cutinase