Microbial Degradation of Disodium Terephthalate

Strain 9-003 was isolated from soil in the textile dying factory for its ability to assimilate disodium terephthalate (DT) as a carbon and energy source. Analysis of the base sequence of 16S ribosomal DNA allowed us to assign the bacterium to Rhodococcus sp., the strain reduced a total concentration of DT from 95.2 to 40.8 mM for 7 d, and showed highest degradation rate (1.0 mM/h) in pH 7.0 culture broth at 25 degrees C, 180 rpm. Oxygen uptake experiments with the resting cells showed the biodegradation process was aerobic. HPLC analysis of the culture broth revealed there was at least one intermediate-protocatechuic acid (PC) involved the microbial degradation process. Substrate spectrum indicated strain 9-003 assimilated DT, PC and p-hydroxybenzoic acid efficiently. The degradation path way of DT was discussed and we propose that DT was metabolized aerobically by Rhodococcus sp. 9-003 via PC.