Phthalic acid esters degradation by a novel marine bacterial strain Mycolicibacterium phocaicum RL-HY01: Characterization, metabolic pathway and bioaugmentation
Phthalic acid esters degradation by a novel marine bacterial strain Mycolicibacterium phocaicum RL-HY01: Characterization, metabolic pathway and bioaugmentation
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新型海洋细菌菌株福卡分枝杆菌 RL-HY01 降解邻苯二甲酸酯：特征、代谢途径和生物增强
DOI：
10.1016/j.scitotenv.2021.148303
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发表时间：
2021
影响因子：
9.8
通讯作者：
Hu Hanqiao
中科院分区：
文献类型：
--
作者：
Ren Lei;Wang Guan;Huang Yongxiang;Guo Jianfu;Li Chengyong;Jia Yang;Chen Sha;Zhou John L.;Hu Hanqiao
邻苯二甲酸酯（PAEs）是应用最广泛的增塑剂之一，也是研究最多的具有内分泌干扰特性的环境污染物。对陆地生态系统中PAEs的调查已经广泛开展，而对海洋环境中PAEs的命运却知之甚少。本研究从潮间带沉积物中分离出一种新的降解邻苯二甲酸二（2-乙基己基）酯（DEHP）的海洋细菌——phocaicumRL-HY01。菌株RL-HY01可以利用一系列PAE增塑剂作为唯一的碳源进行生长。结果表明，菌株RL-HY01在pH（5.0 ~ 9.0）、温度（20℃~ 40℃）和盐度（低于10%）范围内均能有效降解PAEs。其中，当添加吐温-80作为增溶剂时，菌株RL-HY01可以快速降解DEHP，并在48 h内完全降解DEHP （50 mg/L）。菌株RL-HY01降解DEHP的动力学符合改进的Gompertz模型。采用超高效液相色谱-串联质谱法（UHPLC-MS/MS）对菌株RL-HY01的DEHP代谢中间体进行了鉴定，并推导了DEHP的代谢途径。DEHP经β-氧化转化为邻苯二甲酸二乙酯（DEP）， DEP经脱酯化水解为邻苯二甲酸（PA）。PA经水杨酸转化为龙胆酸，进一步用于细胞生长。采用海洋样品对菌株RL-HY01进行生物强化，评价其应用潜力，结果表明菌株RL-HY01可加速海洋样品中DEHP的清除。研究结果提高了我们对PAEs在海洋生态系统中的命运的认识，并为PAEs污染的海洋场地确定了有效的生物修复策略。
Phthalic acid esters (PAEs) are one of the most widely used plasticizers and the well-studied environmental pollutants with endocrine disrupting properties. Investigation about PAEs in terrestrial ecosystem has been extensively conducted while the fate of PAEs in marine environment remains underexplored. In this study, a novel di-(2-ethylhexyl) phthalate (DEHP) degrading marine bacterial strain,Mycolicibacterium phocaicumRL-HY01, was isolated and characterized from intertidal sediments. Strain RL-HY01 could utilize a range of PAE plasticizers as sole carbon source for growth. The effects of different environmental factors on the degradation of PAEs were evaluated and the results indicated that strain RL-HY01 could efficiently degrade PAEs under a wide range of pH (5.0 to 9.0), temperature (20 °C to 40 °C) and salinity (below 10%). Specifically, when Tween-80 was added as solubilizing agent, strain RL-HY01 could rapidly degrade DEHP and achieve complete degradation of DEHP (50 mg/L) in 48 h. The kinetics of DEHP degradation by RL-HY01 were well fitted with the modified Gompertz model. The metabolic intermediates of DEHP by strain RL-HY01 were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis and then the metabolic pathway of DEHP was deduced. DEHP was transformed into di-ethyl phthalate (DEP) via β-oxidation and then DEP was hydrolyzed into phthalic acid (PA) by de-esterification. PA was further transformed into gentisate via salicylic acid and further utilized for cell growth. Bioaugmentation of strain RL-HY01 with marine samples was performed to evaluate its application potential and the results suggested that strain RL-HY01 could accelerate the elimination of DEHP in marine samples. The results have advanced our understanding of the fate of PAEs in marine ecosystem and identified an efficient bioremediation strategy for PAEs-polluted marine sites.