Screening, identification and characteristics of an effective decabromodiphenyl ether degrading aerobic strain

Abstract:

[Objective] To isolate the aerobic strain with high-efficiency in degrading decabromodiphenyl ether (BDE-209) from sediment samples collected from Guiyu town in Guangdong Province, an e-waste recycling area, and investigate its degradation characteristics. [Methods] The strain was identified based on its physio-biochemical characteristics and 16S rRNA sequence analysis. The orthogonal experiment was conducted to determine the optimal degrading conditions, effects of different degradation systems and other factors on the degradation efficiency of the strain. [Results] The strain was identified as Brevibacillus brevis named as GY2. Its five-day degradation efficiency reached 54.38% when the initial concentration of BDE-209 was 1 mg/L. The optimum conditions for BDE-209 degradation were as follows: pH 7, bacterial dosage 3 g/L, and culturing temperature 30 °C. The study also showed that the optimal strain age was 36 h and the best nitrogen source was (NH4)2SO4. B. brevis could tolerate the toxicity of Cu2+ and Cd2+, although the presence of these heavy metals posed certain influence on BDE-209 degradation. As the concentration of Cu2+ and Cd2+ were in the range of 1?5 mg/L and 0.3?0.5 mg/L, respectively, the degradation efficiency of BDE-209 was still over 50%. [Conclusion] B. brevis is effective in degrading BDE-209, the results are of significance and application importance in the study of aerobic microbial degradation and environment bioremediation of BDE-209.

Key words:Decabromodiphenyl ethers, Microbial degradation, Screening, Heavy metal, Characteristics