高效苯系物降解菌群的筛选及其降解性能

Screening of efficient benzene-degrading microbial consortia and degradation performance

从受污染的土壤中富集驯化获得苯系物降解菌群,探究其降解特性并优化降解条件。以苯、甲苯、乙苯和二甲苯作为碳源进行多周期驯化,通过高通量测序技术进行群落结构分析,采用气相色谱法检测菌群对苯的降解性能,通过改变单一因素对降解条件进行优化。驯化后的苯系物降解菌群以假单胞菌属(Pseudomonas)为主,占比56.07%;混合菌群降解苯的最适条件是温度30℃、pH 7、苯浓度200 mg/L,降解率在80%以上;添加Fe^(3+)、Mn^(2+)离子可强化苯的降解,0.5 mg/L的Mn^(2+)和2.0 mg/L的Fe^(3+)对苯的降解率分别达到90.97%和86.63%,比添加前提高8.57%和4.23%;菌群对苯的降解过程符合一级动力学方程,菌群降解200 mg/L苯的半衰期仅为12.27 h。该菌群对苯有较强的降解能力,对苯系物污染场地的修复有一定的应用前景。

A benzene-degrading microbial consortia was obtained from the enrichment and domestication of contaminated soil.Its degradation characteristics were explored and degradation conditions were optimized.Benzene,toluene,ethylbenzene and xylene were used as carbon sources for multi-cycle domestication.Community structure analysis was carried out by high-throughput sequencing technology,the degradation effect of microbial consortia on benzene was detected by gas chromatography,and the degradation conditions were optimized by changing a single factor.The BTEX-degradation microbial consortia after domestication were mainly Pseudomonas,accounting for 56.07%.The optimum conditions for benzene degradation by microbial consortia were an an initial pH of 7,a temperature of 30℃ and benzene concentration of 200 mg/L,and the degradation rate was more than 80%.The addition of Fe^(3+)and Mn^(2+)ions could enhance the benzene degradation efficiency,and the degradation of benzene by 0.5 mg/L Mn^(2+)and 2.0 mg/L Fe^(3+)reached 90.97% and 86.63%,respectively,which were 8.57% and 4.23% higher than before addition.The degradation process of benzene by the microbial consortia conformed to the first-order kinetic equation,and the half-life of the microbial consortia to degrade 200 mg/L benzene was only 12.27 h.This microbial consortia has a strong ability to degrade benzene,and has a certain application prospect for the remediation of benzene contaminated sites.