Yusuke ENDO

Microbial degradation of tris(2-chloroethyl)phosphate, a persistent organic compound.

Ryo-hei YAMADA�CYoshio KERA�CShouji TAKAHASHI

Large quantities of organophosphoric acid triesters have been produced and widely used as flame retardants, plasticizers and pesticides. The compounds are therefore widely distributed in the natural environment. Some of them are known to have acute toxicities, mutagenicity and neurotoxicity, similar to those of organophosphorus pesticides. Although chlorinated triesters such as tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and tris(2-chloroethyl) phosphate (TCEP) have been known to be highly toxic among them, there is no information on the microbial degradation of these chlorinated triesters. In the present study, we succeed in obtaining a mixed culture capable of degrading TCEP.
A TCEP-degrading mixed culture No.45-DE was found capable of growing on both TCEP and TDCPP as the sole phosphorous source. In addition, No.45-DE was also capable of degrading TCEP in the presence of exogenous phosphorous source NaH2PO4(up to 2�~104 ƒÊM), supplied in the culture medium, as an additive source of phosphorus. Denaturing gradient gel electrophoresis (DGGE) pattern of No.45-DE showed multiple bands, indicating that various microorganisms exist in the mixed culture. DGGE profile also showed that bacterial population structure in No. 45D was not changed with time.