产脲节杆菌DnL1-1与小麦联合对阿特拉津降解的影响

Effect of association of Arthrobacter ureafaciens DnL1-1 and wheat on atrazine degradation

【目的】研究产脲节杆菌DnL1-1与小麦联合对阿特拉津污染土壤联合降解修复的作用效果.【方法】利用盆栽试验考察了不同浓度阿特拉津处理下小麦对产脲节杆菌DnL1-1种群密度以及对阿特拉津降解的影响.【结果】随着阿特拉津浓度的逐渐降低,小麦根际及非根际土壤中DnL1-1定殖浓度也逐渐降低;接菌浓度越低,定殖效果越差,相应对阿特拉津的降解效果也越差;不同体积分数阿特拉津处理(5 833.3、466.7、116.7μg/kg)下,DnL1-1与小麦协同对阿特拉津的平均降解率依次为98.4%、92.0%和84.5%,显著高于DnL1-1单独作用;阿特拉津体积分数为116.7μg/kg时,小麦与DnL1-1有效减少了其降解产物DEA、DAA、HA和DIA的残留积累,(DEA、DAA、HA和DIA减少了61.6%、52.2%、9.7%和24.4%.【结论】产脲节杆菌DnL1-1与小麦拌种可有效地减少低浓度阿特拉津及其脱烷基降解产物的积累,对于低浓度阿特拉津污染土壤的原位修复具有一定的应用效果.

【Objective】 In order to investigate the effect of Arthrobacter ureafaciens strain DnL1-1 combined with wheat on remediation of atrazine contaminated soil.【Method】 The effect of wheat plants on the population density and atrazine-degrading activity of DnL1-1 in soil exposed to different doses of the herbicide was investigated with pot experiment.【Result】Along with the decrease of atrazine concentration,the population of DnL1-1 in wheat rhizosphere soil and non-rhizosphere soil gradually decreased. The lower the inoculation dose,the worse the colonization effect,and the worse the degradation effect of atrazine. With different concentrations of atrazine(5 833.3,466.7 and 116.7 μg/kg),the average degradation rate of atrazine by DnL1-1 in coordination with wheat was 98.4,92.0 and 84.5% respectively,which was significantly higher than that of DnL1-1 alone. In association with wheat,DnL1-1 strongly reduced the accumulation of DEA,DAA,DIA and HA(61.6%,52.2%,24.4% and 9.7% respectively) at the 116.7 μg/kg dose of atrazine.【Conclusion】 It is suggested that wheat with A. ureafaciens strain DnL1-1 is a promising method to reduce the low-level contamination of soil with atrazine and its dealkylated metabolites.