十溴联苯醚降解菌的分离鉴定、降解特性及降解机理  

Isolation,identification,degradation characteristics and mechanisms of decabromodiphenyl ether degrading bacteria

作　　者：范罗圣 吴涓[1] 胡丁璠 荚荣[2] FAN Luosheng;WU Juan;HU Dingfan;JIA Rong(School of Resources and Environmental Engineering,Anhui University,Hefei 230601,Anhui,China;School of Life Sciences,Anhui University,Hefei 230601,Anhui,China)

机构地区：[1]安徽大学资源与环境工程学院,安徽合肥230601 [2]安徽大学生命科学学院,安徽合肥230601

出　　处：《微生物学通报》2023年第1期78-90,共13页Microbiology China

基　　金：国家自然科学基金(31970100)。

摘　　要：【背景】十溴联苯醚(decabromodiphenyl ether,BDE-209)是应用最广泛的溴代阻燃剂之一,其持久性毒性给生态环境和生物体带来了严重危害。【目的】分离出一株能有效降解BDE-209的好氧细菌并研究其降解特性及机理,以探究BDE-209的微生物降解规律。【方法】以BDE-209为唯一碳源,通过富集、分离和纯化,从活性污泥中筛选出BDE-209好氧降解细菌。采用高效液相色谱(high-performance liquid chromatography,HPLC)和液相色谱-质谱联用仪(liquid chromatography-mass spectrometry,LC-MS)分别检测BDE-209的浓度和中间产物。【结果】筛选得到一株BDE-209好氧降解细菌F,经鉴定初步判定为硝基还原假单胞菌(Pseudomonas nitroreducens)。在30℃、pH 7.0、接种量为10%(体积分数)、葡萄糖浓度为250 mg/L的优化降解条件下,对初始浓度为10mg/L的BDE-209的降解率可达76.2%。低浓度的Cd2+(≤5mg/L)未对BDE-209的微生物降解和菌体生长产生显著影响,而高浓度的Cd2+(≥15 mg/L)对BDE-209的微生物降解和菌体生长则产生显著影响。BDE-209对细胞表面疏水性(cell surface hydrophobicity,CSH)具有一定的影响。BDE-209的微生物降解机理主要包括脱溴、羟基化、二苯醚键断裂和开环等过程。【结论】菌株F对BDE-209具有很好的降解能力,研究结果对BDE-209的好氧微生物降解及BDE-209污染环境的生物修复具有较好的科学意义。[Background]Decabromodiphenyl ether(BDE-209)is one of the most widely used brominated flame retardants,which has caused serious harm to ecological environment and organisms due to its persistent toxicity.[Objective]To obtain an aerobic bacterium that could effectively degrade BDE-209 and to study its degradation characteristics and mechanisms.[Methods]The aerobic degrading bacterium was isolated from activated sludge by enrichment,isolation and purification using BDE-209 as the sole carbon source.The concentration of BDE-209 and the intermediate products were analyzed by high-performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC-MS),respectively.[Results]A BDE-209 aerobic degrading strain F was screened and preliminarily identified as Pseudomonas nitroreducens.Under the optimal degradation conditions of 30°C,pH 7.0,10%inoculum volume and 250 mg/L glucose,the degradation efficiency reached 76.2%for 10 mg/L(initial concentration)BDE-209.Obvious effects of low Cd2+concentrations(≤5 mg/L)on BDE-209 biodegradation and the growth of P.nitroreducens were not observed,while the effects of high Cd2+concentrations(≥15 mg/L)were significant.In addition,BDE-209 affected cell surface hydrophobicity to some degree.The biodegradation mechanisms of BDE-209mainly included debromination,hydroxylation,cleavage of diphenyl ether bonds and ring opening.[Conclusion]Strain F showed good biodegradation ability for BDE-209.The research results facilitated the aerobic microbial degradation of BDE-209 and the bioremediation of BDE-209 polluted environment.

关 键 词：十溴联苯醚 菌株F 微生物降解 细胞表面疏水性 降解机理 

分 类 号：X172[环境科学与工程—环境科学]