Integration of Membrane Protein Analysis into Model Development for the Biodegradation of Phenol and Toluene by Pseudomonas putida F1

摘要

Pseudomonas putida F1 (PpF1) is a bacterial strain that is capable of degrading toluene and phenol, two widespread environmental pollutants. It has been shown that PpF1 utilizes the same set of cytoplasmic enzymes to degrade both contaminants. However, growth on mixtures of the two contaminants results initially in toluene degradation, followed by phenol degradation only after nearly all of the toluene has been removed. Traditional competitive models do not predict this pattern, although our group has previously obtained a reasonable correlation with a non-specific interaction model. In addition, our group has also shown that the hydrophobicity of the cell membrane increases during degradation of toluene, which suggests that mass transfer of phenol into the cell may be inhibited. The objective of this work is to develop a model for the biodegradation of mixtures of phenol and toluene that involves an appropriate uptake mechanism. A preliminary analysis of a two-step model (uptake and reaction) has shown promising correlation with mixed contaminant data. We are currently developing a two-dimensional electrophoretic method of analyzing membrane proteins to aid in the formulation of a model that describes the actual processes occurring within the cells.