[Characteristics and functional protein analysis of an effective decabromodiphenyl ether-degrading strain]

An effective decabromodiphenyl ether (BDE-209) degrading strain was isolated and identified as Enterococcus casseliflavus based on the 16S rRNA gene sequence analysis. The optimal conditions for strain growth were pH 7 and culture time of 48 h, respectively. E. casseliflavus has a good ability to degrade BDE-209. The biodegradation rate of 1 mg.L-1 BDE-209 by 1 g.L-1 E. casseliflavus reached the highest of 56. 7% after 4 days degradation with 5 mg.L-1 glucose as the additional carbon source. During the degradation process of BDE-209, SDS-PAGE demonstrated that some new extracellular proteins were induced under 2 mg.L-1 and 5 mg.L-1 BDE-209. As for the intracellular proteins, the quantity of protein expression varied, and some proteins even disappeared compared with the blank control. Two-dimensional electrophoresis steps for protein analysis detected 31 different protein points, demonstrating that during the degradation process, the conformation of some proteins which were related with degradation was changed, and resulted in the variation of type and content of the proteins.