Isolation of bacterial strains that produce the endocrine disruptor, octylphenol diethoxylates, in paddy fields

Topsoil samples were collected from 36 different paddy fields in West Japan. Each soil sample was incubated with a basal salt-medium containing 0.2% OPPEO. Twelve samples possessed OP-PEO-degrading activity, from which twelve cultures of OP-PEO-degrading bacteria were isolated. The isolated bacteria grew on a medium containing 0.2% OPPEO as the sole carbon source, and OP2EO and OPHO were accumulated in the medium under aerobic conditions. OP1EO and octylphenol, which have often been identified in surface water together with OP2EO, were not observed in this experiment. The bacterial isolates were gram negative and tentatively identified as Pseudomonas putida (10 isolates) and Burkholderia cepacia (one isolate) by BIO-LOG and 16S rDNA RFLP analyses.