Pure cultures of ammonia-oxidizing bacteria, Nitrosomonas europaea, were exposed to trichloroethyl-Chlorinated solvents, widely used commercially and inene (TCE), 1,1-dichloroethylene (1,1-DCE), chloroform dustrially and often disposed of indiscriminately, are (CF), 1,2-dichloroethane (1,2-DCA), or carbon tetrachloan important environmental issue. Many tend to break ride (CT), in the presence of ammonia, in a quasi-steadystate bioreactor. Estimates of enzyme kinetics constants, down quite slowly under natural, environmental condisolvent inactivation constants, and culture recovery contions and some [e.g., trichloroethylene (TCE)] are not stants were obtained by simultaneously fitting three currently known to support growth of aerobes. Because model curves to experimental data using nonlinear optiof this, treatment or remediation approaches involving mization techniques and an enzyme kinetics model, recometabolism have received much attention. Cometabferred to as the inhibition, inactivation, and recovery (IIR) model, that accounts for inhibition of ammonia oxidation olism of TCE can be accomplished by several bacterial by the solvent, enzyme inactivation by solvent product
species, including those capable of growth on ammonia toxicity, and respondent synthesis of new enzyme (recov- (Arciero et al., 1989;Rasche et al., 1991), cumene (Daery). Results showed relative enzyme affinities for ammo-