Complete Degradation of the Endocrine-Disrupting Chemical Dimethyl Phthalate ester by Flavobacterium sp.

Abstract

The complete microbial degradation of dimethyl phthalate ester (DMPE) is described. DMPE is thought to be an endocrine-disrupting chemical. A pure culture (strain No. A-9) from soil sample capable of utilizing DMPE as the sole source of carbon and energy was identified as Flavobacterium sp. Degradation patterns of DMPE were observed on the high-performance liquid chromatogram (HPLC) of the culture filtrates of this strain, and growth of bacteria was measured as protein by the Kennedy and Fewson method. The growth yield of this strain was about 5.9 g of protein per mole of carbon source of DMPE, and was similar to that in the case of glucose as a carbon source. Complete degradation of DMPE had been achieved (1000 mg/l) in less than 2 days using Flavobacterium sp. strain No. A-9. The transient intermediates of DMPE were not detectable on the HPLC of the culture filtrates of this strain. This strain also degraded phthalic acid (PA) but could not degrade phthalic anhydride.