复合菌对十溴联苯醚的降解特性研究

Degradation characteristics of decabromodiphenyl ether by complex bacteria community

【目的】利用6株十溴联苯醚(decabromodiphenyl ether,BDE-209)降解细菌,探究复合菌对BDE-209的降解特性和降解路径,为BDE-209污染环境的生物修复提供科学依据。【方法】利用高效液相色谱法测定BDE-209的浓度,通过液相色谱-质谱联用仪分析鉴定BDE-209降解产物。【结果】短芽孢杆菌属(Achromobacter sp.)M1和无色杆菌属(Achromobacter sp.)M2的组合对BDE-209的降解效果最好,在30℃、pH值7.0、接种量15%的条件下,120 h后10 mg/L BDE-209的降解效率可达87.7%。相比于单一菌株,复合菌M(1+2)可以更有效、更快地降解BDE-209。在0.5–10 mg/L范围内,复合菌M(1+2)对BDE-209的降解率随着BDE-209初始浓度的增大而增大。通过液相色谱-质谱联用仪(liquid chromatograph-mass spectrometer,LC-MS)检测到11种BDE-209微生物降解产物,复合菌M(1+2)通过脱溴、羟基化、去质子化、醚键断裂和开环等反应对BDE-209进行降解。【结论】复合菌M(1+2)对BDE-209具有良好的降解能力,研究结果为进一步提高微生物对BDE-209污染环境的生物修复能力提供了良好的微生物资源。

[Objective]To investigate the degradation characteristics and degradation paths of decabromodiphenyl ether(BDE-209)by complex bacteria communities based on six strains of BDE-209 degrading bacteria,so as to provide a scientific basis for the remediation of BDE-209-contaminated environments.[Methods]We determined the concentration of BDE-209 by high performance liquid chromatography(HPLC)and identified the degradation products by liquid chromatography-mass spectrometry.[Results]The combination of Brevibacillus sp.(M1)and Achromobacter sp.(M2)had the best degradation capacity for BDE-209.At 30℃,pH 7.0,and an inoculation amount of 15%,the combination showed the degradation efficiency of 87.7%for 10 mg/L BDE-209 after 120 h.The complex bacteria community M(1+2)degraded BDE-209 more efficiently and quickly than the single strains.The degradation efficiency of BDE-209 by M(1+2)increased with the increase in the initial concentration of BDE-209 within the range of 0.5–10 mg/L.Liquid chromatograph-mass spectrometer(LC-MS)identified 11 degradation products of BDE-209.M(1+2)degraded BDE-209 by debromination,hydroxylation,deprotonation,ether bond breaking,and ring opening.[Conclusion]The complex bacteria community M(1+2)demonstrates strong degradation capacity for BDE-209.The findings enriched the microbial resources for improving the bioremediation of BDE-209-contaminated environments.