Radiation-induced impacts on the degradation of 2,4-D and the microbial population in soil microcosms
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- 作者：Bastian Niedré ; e ; b.niedree@fz-juelich.de ; Harry Vereecken1 ; h.vereecken@fz-juelich.de ; Peter Burauel2 ; p.burauel@fz-juelich.de
- 关键词：Mineralization ; 2 ; 4-D ; Dichlorophenoxyacetic acid ; 137Cs ; 90Sr ; 14C ; Chernobyl
- 刊名：Journal of Environmental Radioactivity
- 出版年：2013
- 出版时间：January, 2013
- 年：2013
- 卷：115
- 期：Complete
- 页码：168-174
- 全文大小：635 K
文摘
In a soil microcosm experiment, the influence of low-level 137Cs and 90Sr contamination on the degradation of 14C-ring-labeled 2,4-dichlorophenoxyacetic acid (2,4-D) was studied. Two differently treated soils (one native soil and one soil sterilized and reinoculated with a biotic soil aliquot) were artificially contaminated with various concentrations of 137Cs and 90Sr as nitrate salts. The cumulative doses increased up to 4?Gy for 30 days of incubation in soil microcosms. Changes in microbial community structure were observed with help of the denaturing gradient gel electrophoresis (DGGE). A radiation-induced impact appeared only in the microcosms treated with 30 times the maximum contamination appearing in the exclusion zone around reactor 4 in Chernobyl. In contrast to the less contaminated soils, the mineralization of 2,4-D was delayed for 4 days before it recovered.
Slight shifts in the microbial communities could be traced to radiation effects. However, other parameters had a major impact on mineralization and community structure. Thus the sterilization and reinoculation and, of course, application of the 2,4-D were predominantly reflected in the 14CO2 emissions and the DGGE gel patterns.