Factors affecting the biodegradation of toluene in soil
Factors affecting the biodegradation of toluene in soil
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DOI：
10.1016/0045-6535(96)00152-x
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发表时间：
1996-07-01
期刊：
影响因子：
8.8
通讯作者：
Madsen, S
中科院分区：
文献类型：
--
作者：
Davis, JW;Madsen, S
研究了甲苯在土壤微宇宙中的生物降解，以确定决定有机化学品在土壤中的命运和寿命的物理、化学和生物因素。甲苯的降解速率与初始底物浓度成正比，并且这些速率在200 μ g/g的浓度下达到最大值。在此浓度以上没有发生降解，这可能是由于碳氢化合物对土壤微生物的毒性。在不同含水量的土壤中，降解速率略有差异。然而，土壤中水分的可利用性似乎仅在很低的含水量下限制甲苯的降解，甲苯在土壤中的寿命还与土壤微生物的初始水平和活性有关。甲苯在最初含有高水平降解微生物的土壤中代谢迅速，此外，土壤暴露于甲苯导致降解微生物数量增加。在含有大量降解微生物的粘土中，缺乏无机营养物（如氮）会阻碍甲苯的完全降解。土壤中有机化合物的生物降解不是分子的固有性质，如果不首先描述其存在的环境，就无法预测。化合物的生物降解是由生物、物理、化学和生物学性质来定义的。土壤环境的化学特征。化学品在土壤中的寿命取决于所有这三个参数的组合。版权所有（C）1996 Elsevier Science Ltd
The biodegradation of toluene in soil microcosms was examined in order to identify the physical, chemical, and biological factors which determine the fate and lifetime of organic chemicals in soils, Toluene degradation rates were proportional to the initial substrate concentration and these rates reached a maximum at a concentration of 200 mu g/g. No degradation occurred above this concentration presumably due to the toxicity of the hydrocarbon to the soil microorganisms. Small differences were observed in the degradation rates in soils at different moisture content. However, the availability of water in soil appeared to limit toluene degradation only at a very low water content.The lifetime of toluene in soil was also related to the initial level and activity of the soil microorganisms. Toluene was metabolized rapidly in those soils which initially contained high levels of degrading microorganisms, Furthermore, exposure of the soil to toluene resulted in an increase in the number of degrading organisms. The lack of inorganic nutrients such as nitrogen prevented complete degradation of toluene in a clay soil which contained high levels of degrading microorganisms.The biodegradation of organic chemicals in soil is not an intrinsic property of the molecule and cannot be predicted without first delineating the environment in which it is found. The biodegradation of a compound is defined by the biological, physical, and chemical characteristics of the soil environment. The lifetime of a chemical in soil results from a combination of all three of these parameters. Copyright (C) 1996 Elsevier Science Ltd