Influence of soil properties on the vertical movement of genetically-marked Pseudomonas fluorescens through large soil microcosms
Influence of soil properties on the vertical movement of genetically-marked Pseudomonas fluorescens through large soil microcosms
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DOI：
10.1007/bf00337375
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发表时间：
2004
影响因子：
6.5
通讯作者：
J. D. Elsas;J. Trevors;L. Overbeek
中科院分区：
文献类型：
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作者：
J. D. Elsas;J. Trevors;L. Overbeek
研究了转座子Tn5标记的荧光假单胞菌（Pseudomonasfluorescencells）在50cm长的壤质砂土土柱中的垂直迁移。使用地下水使柱中的土壤缓慢达到饱和，然后缓慢加入足够的水以允许收集饱和水。引入的细菌被运送到较低的土壤层，以显着更高的程度，在原状土芯比在重新包装的核心，水的运输受到阻碍，在这两个核心类型，由于土壤容重高。土壤容重的影响程度的运输引入的细胞，逐步更多的细胞被易位到更深的土层，并进入渗滤水在降低土壤容重。重复渗滤的土壤在体积密度为1.25引起的Tn5标记的细胞数量在较低的土壤层和蒸馏水的增加。此外，最初引入到干燥（5.3%水分）土壤中的细胞比引入到较湿（13%水分）土壤中的细胞移位的程度更小。最后，小麦根系增强了水诱导的运输引入细胞到40和50厘米深的土层，并进入污水，但不是其余的土层。大的土柱，如本研究中使用的是有用的，在各种模拟环境条件下，在土壤中引入的细菌细胞的运输和生存评估。
Vertical translocation of the introduced transposon Tn5-taggedPseudomonas fluorescenscells was studies after irrigation of 50-cm long soil columns of loamy sand. The soil in the columns was slowly brought to saturation using groundwater, and enough water was then slowly added to permit collection of the percolated water. Introduced bacteria were transported to lower soil layers to a significantly higher degree in undisturbed soil cores than in repacked cores; water transport was hampered in both core types due to high soil bulk densities. Soil bulk density affected the degree of transport of the introduced cells; progressively more cells were translocated to deeper soil layers and into the percolation water at decreasing soil bulk densities. Repeated percolation of soil at a bulk density of 1.25 caused an increase in Tn5-tagged cell numbers in the lower soil layers and in the percolated water. Further, cells initially introduced into a dry (5.3% moisture) soil were translocated to a lesser extent than cells introduced into a wetter (13% moisture) soil. Finally, wheat roots enhanced the water-induced transport of introduced cells to the 40- and 50-cm deep soil layers and into the effluent, but not to the remaining soil layers. Large soil columns such as those used in the present study are useful in assessing the transport and survival of introduced bacterial cells in soils under a variety of simulated environmental conditions.