Degradation of Di(2-Ethylhexyl) Phthalate by a Novel Gordonia alkanivorans Strain YC-RL2
Degradation of Di(2-Ethylhexyl) Phthalate by a Novel Gordonia alkanivorans Strain YC-RL2
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新型 Gordonia alkanivorans 菌株 YC-RL2 降解邻苯二甲酸二（2-乙基己基）酯
DOI：
10.1007/s00284-016-1159-9
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发表时间：
2017-03-01
影响因子：
2.6
通讯作者：
Yan, Yanchun
中科院分区：
文献类型：
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作者：
Nahurira, Ruth;Ren, Lei;Yan, Yanchun
从石油污染土壤中分离到的一株细菌YC-RL 2能利用环境激素邻苯二甲酸二（2-乙基己基）酯（DEHP）作为唯一碳源生长。经16 S rRNA基因分析和Biolog鉴定，菌株YC-RL 2为戈登氏菌（Gordonia alkanivorans）。在30 °C和pH 8.0的条件下，对影响降解过程的环境因素进行了优化。菌株YC-RL 2表现出上级的耐盐性，在添加DEHP的微量元素培养基中，可耐受0- 5%NaCl，但随着NaCl浓度的增加，DEHP降解速率减慢。在较宽的pH范围内（6.0-11.0）也表现出优异的性能。菌株YC-RL 2对高浓度DEHP（100 ~ 800 mg/L）的降解率均在94%以上。通过HPLC-MS检测到DEHP的中间产物，初步推断了DEHP的降解途径。DEHP通过邻苯二甲酸单（2-乙基己基）酯（MEHP）转化为邻苯二甲酸（PA），PA通过苯甲酸（BA）进一步用于生长。从菌株YC-RL 2中鉴定出预期催化MEHP水解为PA的酶。进一步的研究发现，该酶可以催化多种邻苯二甲酸单烷基酯转化为PA。
One bacterial strain, YC-RL2, isolated from petroleum-contaminated soil, could utilize environmental hormone Di(2-Ethylhexyl) phthalate (DEHP) as a sole carbon source for growth. Strain YC-RL2 was identified as Gordonia alkanivorans by 16S rRNA gene analysis and Biolog tests. The effects of environmental factors which might affect the degrading process were optimized at 30 °C and pH 8.0. Strain YC-RL2 showed superior halotolerance and could tolerate up to 0–5% NaCl in trace element medium supplemented with DEHP, although the DEHP degradation rates slowed as NaCl concentration increased. It also showed an outstanding performance in a wide range of pH (6.0–11.0). Meanwhile, strain YC-RL2 was able to withstand high concentrations of DEHP (from 100 to 800 mg/L), and the degradation rates were all above 94%. The DEHP intermediates were detected by HPLC–MS, and the degradation pathway was deduced tentatively. DEHP was transformed into phthalic acid (PA) via mono (2-ethylhexyl) phthalate (MEHP), and PA was further utilized for growth via benzoic acid (BA). The enzyme expected to catalyze the hydrolysis of MEHP to PA was identified from strain YC-RL2. Further investigation found that the enzyme could catalyze the transformation of a wide range of monoalkyl phthalates to PA.