A two-step model for the kinetics of BTX degradation and intermediate formation by Pseudomonas putida F1.

A two-step model is developed for the aerobic biodegradation of benzene, toluene, and p-xylene (BTX) by Pseudomonas putida F1. The model contains three unique features. First, an initial dioxygenation step transforms BTX into their catechol intermediates, but does not support biomass growth. Second, the benzene or toluene intermediates are mineralized, which supports biomass synthesis. Third, BTX exhibit competitive inhibition on each other's transformation, while toluene and benzene noncompetitively inhibit the mineralization of their catechol intermediate. A suite of batch and chemostat experiments is used to systematically measure the kinetic parameters for the two-step transformations and the substrate interactions.