Role of chemotaxis in the transport of bacteria through saturated porous media

Ford, Roseanne M.; Harvey, Ronald W.

doi:10.1016/j.advwatres.2006.05.019

Cited by 142 publications

(139 citation statements)

References 53 publications

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“…Although significant advances have been made in understanding the effect of bacterial chemotaxis at the pore scale [23], much about the macroscale significance of chemotaxis for bacteria is still poorly understood [24]. However, DAPI, which is known to hamper bacterial activity [25], has recently been shown to inhibit chemotactic activity in groundwater bacteria [26].…”

Section: Governing Equationsmentioning

confidence: 99%

Revisiting the Cape Cod Bacteria Injection Experiment Using a Stochastic Modeling Approach

Maxwell

Welty

Harvey

2007

Environ. Sci. Technol.

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Bromide and resting-cell bacteria tracer tests carried out in a sand and gravel aquifer at the USGS Cape Cod site in 1987 were reinterpreted using a three-dimensional stochastic approach and Lagrangian particle tracking numerical methods. Bacteria transport was strongly coupled to colloid filtration through functional dependence of local-scale colloid transport parameters on hydraulic conductivity and seepage velocity in a stochastic advection-dispersion/attachment-detachment model. Information on geostatistical characterization of the hydraulic conductivity (K) field from a nearby plot was utilized as input that was unavailable when the original analysis was carried out. A finite difference model for groundwater flow and a particle-tracking model of conservative solute transport was calibrated to the bromide-tracer breakthrough data using the aforementioned geostatistical parameters. An optimization routine was utilized to adjust the mean and variance of the lnK field over 100 realizations such that a best fit of a simulated, average bromide breakthrough curve is achieved. Once the optimal bromide fit was accomplished (based on adjusting the lnK statistical parameters in unconditional simulations), a stochastic particle-tracking model for the bacteria was run without adjustments to the local-scale colloid transport parameters. Good predictions of the mean bacteria breakthrough data were achieved using several approaches for modeling components of the system. Simulations incorporating the recent Tufenkji and Elimelech

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Section: Governing Equationsmentioning

confidence: 99%

Revisiting the Cape Cod Bacteria Injection Experiment Using a Stochastic Modeling Approach

Maxwell

Welty

Harvey

2007

Environ. Sci. Technol.

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“…Natural microswimmers usually do not move in homogeneous environments but encounter soft and solid walls, obstacles [12][13][14][15][16], or even more complex environments like the intestinal tract [17], porous soil [18], and blood flow [19]. A heterogeneous environment can be realized in different ways, both in experiments and theory, e.g., by regular or irregular patterns of obstacles [20][21][22][23][24][25][26][27][28][29][30][31][32], mazes [33], arrays of funnels [16,[34][35][36][37][38], pinning substrates [39], or patterned light fields, which control the velocity of the microswimmer [40,41].…”

Section: Introductionmentioning

confidence: 99%

Active Brownian particles moving in a random Lorentz gas

2017

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Abstract. Biological microswimmers often inhabit a porous or crowded environment such as soil. In order to understand how such a complex environment influences their spreading, we numerically study noninteracting active Brownian particles (ABPs) in a two-dimensional random Lorentz gas. Close to the percolation transition in the Lorentz gas, they perform the same subdiffusive motion as ballistic and diffusive particles. However, due to their persistent motion they reach their long-time dynamics faster than passive particles and also show superdiffusive motion at intermediate times. While above the critical obstacle density η c the ABPs are trapped, their long-time diffusion below ηc is strongly influenced by the propulsion speed v 0. With increasing v0, ABPs are stuck at the obstacles for longer times. Thus, for large propulsion speed, the long-time diffusion constant decreases more strongly in a denser obstacle environment than for passive particles. This agrees with the behavior of an effective swimming velocity and persistence time, which we extract from the velocity autocorrelation function.

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“…In heterogeneous systems, bacterial motility is often biased by chemotaxis that guides bacteria toward higher concentrations of nutrients (or away from toxic compounds) [Fenchel, 2002;Stocker et al, 2008]. Chemotaxis has been observed in soil where motile bacteria show chemotactic response to a variety of pollutants considered as potential nutrient sources [Parales et al, 2000;Olson et al, 2004;Kohlmeier et al, 2005;Ford and Harvey, 2007].…”

Section: Introductionmentioning

confidence: 99%

Microbial dispersal in unsaturated porous media: Characteristics of motile bacterial cell motions in unsaturated angular pore networks

Ebrahimi

2014

Water Resources Research

110

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The dispersal rates of self-propelled microorganisms affect their spatial interactions and the ecological functioning of microbial communities. Microbial dispersal rates affect risk of contamination of water resources by soil-borne pathogens, the inoculation of plant roots, or the rates of spoilage of food products. In contrast with the wealth of information on microbial dispersal in water replete systems, very little is known about their dispersal rates in unsaturated porous media. The fragmented aqueous phase occupying complex soil pore spaces suppress motility and limits dispersal ranges in unsaturated soil. The primary objective of this study was to systematically evaluate key factors that shape microbial dispersal in model unsaturated porous media to quantify effects of saturation, pore space geometry, and chemotaxis on characteristics of principles that govern motile microbial dispersion in unsaturated soil. We constructed a novel 3-D angular pore network model (PNM) to mimic aqueous pathways in soil for different hydration conditions; within the PNM, we employed an individual-based model that considers physiological and biophysical properties of motile and chemotactic bacteria. The effects of hydration conditions on first passage times in different pore networks were studied showing that fragmentation of aquatic habitats under dry conditions sharply suppresses nutrient transport and microbial dispersal rates in good agreement with limited experimental data. Chemotactically biased mean travel speed of microbial cells across 9 mm saturated PNM was $3 mm/h decreasing exponentially to 0.45 mm/h for the PNM at matric potential of 215 kPa (for 235 kPa, dispersal practically ceases and the mean travel time to traverse the 9 mm PNM exceeds 1 year). Results indicate that chemotaxis enhances dispersal rates by orders of magnitude relative to random (diffusive) motions. Model predictions considering microbial cell sizes relative to available liquid pathways sizes were in good agreement with experimental results for unsaturated soils. The new modeling platform enables quantitative consideration of key biophysical factors (e.g., pore space heterogeneities and hydration conditions) governing microbial interactions in 3-D soil pore spaces.

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Role of chemotaxis in the transport of bacteria through saturated porous media

Cited by 142 publications

References 53 publications

Revisiting the Cape Cod Bacteria Injection Experiment Using a Stochastic Modeling Approach

Revisiting the Cape Cod Bacteria Injection Experiment Using a Stochastic Modeling Approach

Active Brownian particles moving in a random Lorentz gas

Microbial dispersal in unsaturated porous media: Characteristics of motile bacterial cell motions in unsaturated angular pore networks

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