Abstract
The diauxic growth in a batch culture with acetic acid and oxalic acid was investigated for the effective biodegradation of organic acids which were produced by ozonolysis of pulp wastewater. As it was necessary to degrade all substrates in a continuous culture with mixed substrates, the stability of the steady state which degrade all substrates was to be examined. Stability of steady states was discussed through the eigen values using the previously proposed diauxic model. The number and stability of steady states varied remarkably with operational conditions such as dilution rate and feed substrate concentrations. The three steady states existed, one was the steady state where both substrates were consumed, another was the steady state where only one substrate was consumed and the other was washout. The operational method was studied to obtain the steady state where both substrates were consumed by the diauxic model.
