Independent prediction of naphthalene transport and biodegradation in soilwith a mathematical model

Experiments were performed to test the ability of a mathematical model to p redict naphthalene transport and biodegradation. Pseudomonas putida G7, a m odel bacterial strain capable of degrading naphthalene, was added to a colu mn packed with the soil that had been pre-equilibrated with naphthalene. Mo del prediction for transport and degradation were based on predetermined pa rameters that described naphthalene desorption kinetics and the utilization of naphthalene by the test bacterium. However, initial prediction for naph thalene biodegradation was high, and the formation of cell aggregates is ad vanced as a plausible explanation. Access of substrate to cells in the inte rior of an aggregate would be restricted. When the numerical simulation was conducted with a factor to account for cell aggregation, it successfully d escribed the experimental data. Thus, with a single adjustable parameter (a n average effectiveness factor), the model predicted macroscopic responses of naphthalene in soil-columns where naphthalene was subject to transport a nd biodegradation. (C) 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 65: 6 5-75, 1999.