| 徐伟慧,刘帅,王志刚.一株DMP降解菌的分离鉴定及特性研究[J].农业环境科学学报,2018,37(8):1724-1732. |
| 一株DMP降解菌的分离鉴定及特性研究 |
| Isolation, identification, and degradation characteristics of a DMP-degrading strain |
| 投稿时间：2018-01-16 |
| DOI：10.11654/jaes.2018-0089 |
| 中文关键词: 邻苯二甲酸二甲酯 16S rDNA 降解动力学 降解基因 中间代谢物 |
| 英文关键词: dimethyl phthalate 16S rDNA degradation kinetics degradation gene intermediate metabolites |
| 基金项目:国家自然科学基金项目（31670375）；农业部华南都市农业重点实验室开放基金项目（003） |
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| 摘要点击次数: 1970 |
| 全文下载次数: 2036 |
| 中文摘要: |
| 为分离邻苯二甲酸二甲酯（DMP）降解菌，本研究以长期覆盖塑料废弃物垃圾场的土壤为试材，采用选择性培养基筛选降解DMP的菌株，并研究其降解和生长特性。结果表明，分离获得了一株能降解DMP的菌株QD15-1，根据其菌落的形态特征、生理生化试验及16S rDNA碱基序列同源性分析，鉴定QD15-1为Paracoccus sp.，革兰氏阴性。底物利用试验表明，菌株QD15-1具有降解多种邻苯二甲酸酯（PAEs）的能力；以DMP为唯一碳源，菌株QD15-1生长的最佳条件为pH 8，温度30℃；动力学试验表明，降解DMP过程符合一级动力学方程，随着DMP初始浓度的增加，半衰期缩短；该菌株中含有降解PAEs的基因——邻苯二甲酸双加氧酶基因（PAphtAb）和3，4-二羟基-3，4-二氢邻苯二甲酸脱氢酶基因（PAphtB）。液相质谱试验表明，降解的中间产物有邻苯二甲酸单酯、邻苯二甲酸，推测其降解DMP的途径为：将DMP降解成邻苯二甲酸单酯，再分解成邻苯二甲酸（PA），通过PAphtAb和PAphtB的作用进一步降解。综上所述，QD15-1是一株高效降解DMP的菌株，在修复DMP污染方面有一定的应用前景。 |
| 英文摘要: |
| To isolate a dimethyl phthalate(DMP) -degrading strain, the soil that had been exposed to long-term plastic pollution was collected and used. The DMP-degrading strain was screened out using selective media method, and identified by morphological, physiological, and biochemical analyses, as well as 16S rDNA sequence analysis. Moreover, the degradation characteristics were studied. The results showed that the DMP-degraded strain was classified as Paracoccus sp., named as QD15-1 and belongs to Gram-negative bacterium. The substrate utilization tests showed that the QD15-1 strain could utilize phthalic acid esters(PAEs)pollutants, such as DMP, dibutyl phthalate(DBP), diethyl phthalate(DEP)and diethylhexyl phthalate(DEHP). When DMP was the only carbon source, the optimized conditions of the QD15-1 strain were as follows:pH, 8; temperature, 30℃. The degradation kinetics of QD15-1 were studied in varied initial DMP concentrations under optimal conditions; the results indicated that degradation of DMP conforms to the pseudo-first order kinetic equation, and the half life of DMP was shortened as the initial concentration was increasing up. Importantly, PCR analysis showed the QD15-1 strain to contain PAE-degrading genes, such as the phthalate dioxygenase gene(PAphtAb), and 3, 4-dihydroxy-3, 4-dihydrophthalate dehydrogenase (PAphtB). Liquid mass spectrometry showed that the intermediate metabolites in the minimal medium included o-benzene dicarboxylic acid monoester and phthalic acid. The DMP degradation pathway in the gram-negative strain Paracoccus sp. QD15-1 was speculated to operate as follows:DMP was degraded into o-benzene dicarboxylic acid monoester, decomposed into phthalic acid, and was then further degraded by the above-mentioned genes. These results indicate that QD15-1 is a high-efficiency DMP-degrading strain, and it is expected that the strain QD15-1 could be used to clear DMP pollution in future. |
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