Theoretical and experimental modelling of bacterial transport through particulate matter
Microbial interactions and communication in the soil require the transport of metabolites between organisms producing and responding to soluble compounds. However, little quantitative information is known about the range or speed of the transport of such compounds and of microbial cells, and their effect on microbial dispersal. In this study, a combination of theoretical modelling and experimental microcosm systems have been employed to determine the combined effects of microbial growth, nutrient diffusion and utilisation and motility on the transport of cells through particulate material. A mathematical model has been constructed with defined hypotheses regarding these processes which generates predictions of the changes in cell concentration with time and with distance. Predictions of the model are tested experimental in sand microcosms inoculated with luminescence-marked motile and non-motile strains of Pseudomonas fluorescens and supplied with glucose. The model has been tested under different matric potentials and nutrient concentrations to simulate factors considered to be of importance in the soil environment.