首页> 外文期刊>FEMS Microbiology Ecology >Reduction in denitrification activity in field soils exposed to long term contamination by 2,4,6-trinitrotoluene (TNT)
【24h】

Reduction in denitrification activity in field soils exposed to long term contamination by 2,4,6-trinitrotoluene (TNT)

机译:受到2,4,6-三硝基甲苯(TNT)长期污染的野外土壤中反硝化活性的降低

获取原文
获取原文并翻译 | 示例

摘要

Terrestrial sites contaminated with 2,4,6-trinitrotoluene (TNT) are a widespread and persistent problem and often contain non-vegetated areas with TNT concentrations well in excess of 1000 mg kg(-1). In this study, we examined the effect of TNT on denitrification activity in field soils, and compared the sensitivity of denitrifying: enzymes to TNT. DNA probes assessed the prevalence of nirS, nirK and nosZ (encoding cd(1) or copper nitrite reductase and nitrous oxide reductase, respectively), denitrifying genotypes in the culturable and total microbial community. The nitrate (NaR), nitrite (NiR) and nitrous oxide (N2OR) reductase activities in field soil and in isolates were assessed by gas chromatography. The relative occurrence of the nirK, nirS or nosZ genotypes increased in the cultured community and in total uncultured community DNA as nitroaromatic concentrations increased. However, denitrifying activity decreased in response to increasing TNT concentrations! with an IC50 for NaR+NiR+nitric oxide reductase (NOR) of 400 mg TNT kg(-1) soil and for N2OR of 26 mg TNT kg(-1) soil. The denitrifying activity of four soil isolates also decreased in response to TNT, with N2OR activity being three times more sensitive to TNT than NaR+NiR+NOR activity. Interestingly, there were 118 times more nirK isolates than nirS isolates in uncontaminated soil but only 1.5 times more in soil containing 17400 mg kg(-1) TNT. The results from this study indicated that TNT reduced denitrification activity in field soils, and N2OR was much more sensitive to TNT than NaR+NiR+hTOR. Crown copyright (C) 2000 Published by Elsevier Science B.V. All rights reserved. [References: 26]
机译:被2,4,6-三硝基甲苯(TNT)污染的陆地站点是一个广泛而持久的问题,通常包含TNT浓度远远超过1000 mg kg(-1)的非植被区域。在这项研究中,我们研究了田间土壤中TNT对反硝化活性的影响,并比较了反硝化酶对TNT的敏感性。 DNA探针评估了nirS,nirK和nosZ(分别编码cd(1)或亚硝酸铜还原酶和一氧化二氮还原酶)的发生率,从而在可培养和总微生物群落中反硝化基因型。通过气相色谱法评估了田间土壤和分离物中硝酸盐(NaR),亚硝酸盐(NiR)和一氧化二氮(N2OR)还原酶的活性。随着硝基芳香烃浓度的增加,在培养的群落和未培养的群落总DNA中,nirK,nirS或nosZ基因型的相对发生率增加。但是,反硝化活性随TNT浓度的增加而降低!对于NaR + NiR +一氧化氮还原酶(NOR)为400 mg TNT kg(-1)土壤,对于N2OR为26 mg TNT kg(-1)土壤,IC50为50。四种土壤分离物的反硝化活性也响应于TNT而降低,N2OR活性对TNT的敏感性是NaR + NiR + NOR活性的三倍。有趣的是,在未受污染的土壤中,nirK分离物比nirS分离物多118倍,但在含有17400 mg kg(-1)TNT的土壤中,仅nirS分离物多1.5倍。这项研究的结果表明,TNT降低了田间土壤的反硝化活性,并且N2OR对TNT的敏感性比NaR + NiR + hTOR的高得多。官方版权(C)2000,由Elsevier Science B.V.保留所有权利。 [参考:26]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号