金属离子对赤红球菌(Rhodococcus ruber L9)降解芘的影响及其作用机制  

Effect of metal ions on the degradation of pyrene by Rhodococcus ruber L9 and its mechanism of action

作　　者：阮珍 刘永军 刘静 刘磐 RUAN Zhen;LIU Yongjun;LIU Jing;LIU Pan(Shaanxi Key Lab of Environmental Engineering,Key Lab of Northwest Water Resources,Environment and Ecology Ministry of Education,Xi'an University of Architecture and Technology,Xi'an,710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院陕西省环境工程重点实验室西北水资源与环境生态教育部重点实验室

出　　处：《环境化学》2019年第12期2649-2656,共8页Environmental Chemistry

基　　金：国家自然科学基金(51178377)资助~~

摘　　要：实验室从石油污染土壤中筛选得到一株高效芘降解菌,命名为赤红球菌(Rhodococcus ruber L9),分析了不同浓度Fe^3+、Ca^2+、Cu^2+、Mn^2+对该菌降解芘效果的影响.结果发现,0.45 mmol·L^-1 Fe^3+对芘的降解率有明显促进作用,6 d时芘降解率最高,可达77%,相较于不加金属离子时提升了约30%.进一步研究发现,当Fe^3+存在时,芘降解过程中蛋白总量变化、邻苯二酚1,2-双加氧酶(C120)和邻苯二酚2,3-双加氧酶(C230)酶活性的变化与Fe^3+和Fe^2+在胞内、胞外浓度的变化密切相关,主要原因是Fe^3+的存在,能诱导赤红球菌合成更多与芘降解有关的蛋白,且可以作为酶的活性中心提高酶的活性,从而大幅提高芘的降解效率.High-efficiency pyrene-degrading bacteria,Rhodococcus ruber L9,was isolated from petroleum contaminated soil.The degradation effect of four metal ions(Fe^3+,Ca^2+,Cu^2+,and Mn^2+)on pyrene was investigated in this study.The results showed that 0.45 mmol·L^-1 Fe^3+considerably enhanced the degradation efficiency of pyrene.The degradation rate of pyrene reached a maximum of 77% on day 6,which was about 30% higher than that of the control group.Furthermore,we found that when Fe^3+was present during the degradation process,changes in the activity of catechol 1,2-dioxygenase(C120)and catechol 2,3-dioxygenase(C230)and the concentrations of protein were strictly related to changes in intracellular and extracellular Fe3+and Fe^2+ concentrations.This is because the presence of Fe3+induced Rhodococcus ruber L9 to synthesize large quantities of catechol 1,2-dioxygenase and functioned as an active site in the enzyme to increase enzyme activity,thereby drastically improving the degradation efficiency of pyrene.

关 键 词：FE^3+ 赤红球菌( RHODOCOCCUS ruber L9) 芘降解 邻苯二酚双加氧酶 作用机制 

分 类 号：X172[环境科学与工程—环境科学] X592