RESUMO
In order to investigate the characteristics of the microbial degradation of tetrabromobisphenol A (TBBPA), four aerobic strains were isolated from the phenol granular sludge using selective medium with TBBPA as the sole carbon source. Among them, strain H could accommodate the TBBPA culture medium and degrade TBBPA with high efficiency, which was identified as Rhodococcus sp. via DNA sequencing test. The optimal conditions for TBBPA degradation by strain H was pH 6.5, 30 degrees C, 150 r x min(-1), the concentration of humic acid being 200 mg x L(-1) and the concentration of K+ being 1 000 mg x L(-1). Under the optimal conditions, the debromination rate of TBBPA reached 20.75% after 21 d. The results of LC-MS showed that the major degradation product was monobromophenol, which was formed by the removal of isopropyl from the benzene ring in TBBPA molecule. The results of protein gel electrophoresis (SDS-PAGE) showed that strain H had a protein band between (90-117) x 10(3) kDa, which might be the enzyme responsible for TBBPA degradation.
