DYNAMIC MODELING OF META-NITROBENZOATE AND PARA-NITROBENZOATE METABOLISM BY A MIXED CO-IMMOBILIZED CULTURE OF COMAMONAS SPP. JS46 AND JS47

A model describing the transient activity of a mixed immobilized cultu re of Comamonas spp. JS46 and JS47 growing on mixed substrates is pres ented. The transient periods considered are those following changes in the feed carbon source, which alternated between meta- and para-nitro benzoate, The feed profile alternately starved one of the species in t he mixed culture. The response of the system, as quantified by the rea ctor effluent substrate concentrations, is dictated by the activity of the biomass and the appropriate biochemical pathway. As detailed mech anistic pathway information is not available, respirometry has been us ed to characterize both facets of activity. Two parameters were introd uced: psi representing pathway activity and Gamma representing biomass activity; a detailed description of the analysis is included. The mod el is compared to experimental investigation of the system and describ es the reactor response well. The agreement between model and experime nt suggests the usefulness of oxygen kinetics as global measurements t o describe complex systems when mechanistic detail is not available. ( C) 1998 John Wiley & Sons, Inc.