Role of chemotaxis in the transport of bacteria through saturated porous media
Role of chemotaxis in the transport of bacteria through saturated porous media
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DOI：
10.1016/j.advwatres.2006.05.019
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发表时间：
2007-06-01
影响因子：
4.7
通讯作者：
Harvey, Ronald W.
中科院分区：
文献类型：
--
作者：
Ford, Roseanne M.;Harvey, Ronald W.
趋化性细菌群体能够感知和响应周围环境中的化学梯度，并将其迁移到它们认为有利于其生存的化学物质浓度增加的方向。有人认为，这种现象可能有助于生物修复过程，使细菌更接近它们降解的化学污染物。为了确定在这些过程中的趋化性的意义，有必要量化的响应幅度，并将其与其他影响细菌的命运和运输的地下水过程进行比较。我们提出了一个系统的方法，在实验室规模的实验中量化细菌的趋化反应，从简单的，定义明确的系统开始，并逐渐增加其复杂性。通过跟踪显微镜记录的轨迹评估单个细胞的游泳特性。这些属性被用来计算运动和趋化性系数的细菌种群在散装水介质中进行了比较扩散研究的实验结果。分析了单孔、孔网络和填充柱中运动系数和趋化系数的有效值。这些被用来估计在多孔介质中的趋化反应的大小，并与分散系数在该领域的报道进行比较。这是多年来许多研究报告的汇编。虽然这种方法对于最终量化粒状含水层介质中的运动性和趋化性肯定存在局限性，但它确实提供了对可能的数量级响应以及细菌和介质的哪些特性预计是重要的深入了解。(C)2006爱思唯尔有限公司保留所有权利。
Populations of chemotactic bacteria are able to sense and respond to chemical gradients in their surroundings and direct their migration toward increasing concentrations of chemicals that they perceive to be beneficial to their survival. It has been suggested that this phenomenon may facilitate bioremediation processes by bringing bacteria into closer proximity to the chemical contaminants that they degrade. To determine the significance of chemotaxis in these processes it is necessary to quantify the magnitude of the response and compare it to other groundwater processes that affect the fate and transport of bacteria. We present a systematic approach toward quantifying the chemotactic response of bacteria in laboratory scale experiments by starting with simple, well-defined systems and gradually increasing their complexity. Swimming properties of individual cells were assessed from trajectories recorded by a tracking microscope. These properties were used to calculate motility and chemotaxis coefficients of bacterial populations in bulk aqueous media which were compared to experimental results of diffusion studies. Then effective values of motility and chemotaxis coefficients in single pores, pore networks and packed columns were analyzed. These were used to estimate the magnitude of the chemotactic response in porous media and to compare with dispersion coefficients reported in the field. This represents a compilation of many studies over a number of years. While there are certainly limitations with this approach for ultimately quantifying motility and chemotaxis in granular aquifer media, it does provide insight into what order of magnitude responses are possible and which characteristics of the bacteria and media are expected to be important. (C) 2006 Elsevier Ltd. All rights reserved.