Journal of Environmental Radioactivity, Jan, 2013, Vol.115, p.168(7)
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvrad.2012.08.008 Byline: Bastian Niedree, Harry Vereecken, Peter Burauel Abstract: In a soil microcosm experiment, the influence of low-level.sup.137Cs and.sup.90Sr contamination on the degradation of.sup.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.sup.137Cs and.sup.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.sup.14CO.sub.2 emissions and the DGGE gel patterns. Author Affiliation: Agrosphere Institute, Forschungszentrum Julich GmbH, 52425 Julich, Germany Article History: Received 3 April 2012; Revised 7 August 2012; Accepted 12 August 2012
Nuclear Radiation ; Soil Microbiology
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