草本植物根际邻苯二甲酸二(2-乙基己基)酯降解菌的分离与降解特性

Isolation, identification, and degradation capabilities of the herbaceous plant rhizosphere on di-(2-ethylhexyl)phthalate

为研究湿地草本植物根际对邻苯二甲酸二(2-乙基己基)酯(DEHP)的微生物修复潜能,选择DEHP作为目标污染物,采用富集驯化法从不同湿地草本植物根际土壤中筛选出一株能高效降解DEHP的细菌B6,通过形态、生理生化特征、16S rDNA序列分析,初步鉴定为简单芽孢杆菌(Bacillus simplex),同时研究了该菌株在不同DEHP初始浓度、pH、接菌量、温度条件下对DEHP的降解特性。结果表明,菌株B6的最适降解条件为初始浓度100 mg·L^(-1)、pH 7.0、接菌量4%、温度30℃,在此最适条件下7 d后无机盐培养液中DEHP的降解率为97.91%。研究表明,菌株B6对DEHP污染修复效果显著,在DEHP污染修复中具有一定的应用前景。

The potential of the herbaceous plant rhizosphere to induce microbial remediation of di-(2-ethylhexyl)phthalate(DEHP)in wetlands contaminated by phthalate esters(PAEs)was researched. DEHP was selected as a target pollutant and B6, a strain capable of degrading it efficiently, was isolated by culture methods from the rhizosphere soil of different herbaceous plants in the contaminated wetlands.Based on its morphology, physiology, biochemical characteristics and an 16S rDNA sequencing analysis, B6 was identified as Bacillus simplex.Simultaneously, the DEHP degradation ability of this strain under different initial DEHP concentrations, pH, inoculum amount, and temperature was studied.The optimal degradation conditions for strain B6 were found to be as follows:initial concentration of 100 mg·L^(-1), pH 7.0, inoculum amount 4%, and temperature 30 ℃.Under these conditions, the DEHP degradation rate was 97.91% after 7days in an inorganic salt medium.Our results indicated that B6 has a significant remediation effect and certain potential for application towards remediating DEHP pollution. This study could provide a theoretical basis for the removal of PAE pollution using constructed herbaceous vegetation wetlands.