磷酸三(1-氯-2-丙基)酯降解菌筛选及其降解特性

Screening of tris-(1-chloro-2-propyl) phosphate-degrading bacteria and its degradation characteristics

摘要:

【背景】磷酸三(1-氯-2-丙基)酯[tris-(1-chloro-2-propyl) phosphate, TCIPP]作为全球广泛关注的新兴有机污染物，具有环境赋存含量高、不易生物降解等特点，亟须开发TCIPP的高效去除技术。【目的】获得具有较高TCIPP降解效率并可用于TCIPP污染修复的新菌株。【方法】利用梯度提高无机盐培养基中TCIPP浓度的方法，从TCIPP污染土壤中筛选出1株能够降解液体中高浓度TCIPP (100 mg/L)的菌株，根据16S rRNA基因序列分析对其进行鉴定，并首次对其降解液体中TCIPP的特性进行研究。【结果】所筛选的TCIPP降解菌株DT-6为苍白杆菌(Ochrobactrum sp.)，它能够利用TCIPP作为唯一碳源和能源；当TCIPP初始浓度为50 mg/L、培养时间为7 d时DT-6的生物量最大，对TCIPP的降解率也达到最高，为34.6%；蔗糖的加入能够显著促进DT-6的生长，但却抑制了其对TCIPP的降解。【结论】本研究报道了一株TCIPP高效降解菌Ochrobactrum sp. DT-6，能够为环境中TCIPP污染的生物修复提供新的种质资源。

关键词:磷酸三(1-氯-2-丙基)酯;微生物降解;菌株筛选;降解特性

Abstract:

[Background] Tris-(1-chloro-2-propyl) phosphate (TCIPP), as an emerging organic pollutant of global wide concern, has the characteristics of high environmental concentration, difficult biodegradation, etc. It is urgent to develop efficient removal technology for TCIPP. [Objective] To obtain a new strain with high TCIPP degradation efficiency that can be used for TCIPP pollution remediation.[Methods] The strain which could degrade TCIPP with high concentration (up to 100 mg/L) in liquid was isolated from the TCIPP-contaminated soil by gradually increasing the concentration of TCIPP in the mineral salt medium. The strain was preliminarily identified according to 16S rRNA gene sequence analysis, and its characteristics of degrading TCIPP in liquid were further investigated. [Results] The strain DT-6 was identified as Ochrobactrum sp., and it could utilize TCIPP as the only carbon and energy source. When the initial concentration of TCIPP was 50 mg/L and the incubation time was 7 d, the biomass of the DT-6 strain was the largest and the degradation rate of TCIPP reached the highest (34.6%). The addition of sucrose significantly promoted the growth of the DT-6 strain but inhibited the degradation of TCIPP. [Conclusion] This study reported a highly efficient TCIPP-degrading strain, Ochrobactrum sp. DT-6, which could provide new germplasm resources for the bioremediation of TCIPP pollution in the environment.

Key words:tris-(1-chloro-2-propyl) phosphate;microbial degradation;strain screening;degradation characteristics