Influences of metals on kinetics of methyl tert-butyl ether biodegradation by Ochrobactrum cytisi

The influence of zinc, manganese, and nickel on the degradation of MTBE (methyl tert-butyl ether), by an aerobic MTBE-degrading strain, Ochrobactrum cytisi, were investigated. The result showed that unlike previous findings, O. cytisi was able to degrade MTBE through direct metabolism when MTBE was present as the only carbon source. The degradation rate of MTBE was rapid, completed within 80 h. MTBE biodegradation by this strain was stimulated at low concentrations of Zn2+ (1(-5) mg 1(-1)) and Mn2+ (1(-5) mg 1(-1)) but inhibited at high concentrations of Zn2+ (20 mg 1(-1)) and Mn2+ (20 mg 1(-1)), and at low concentration of Ni2+ (1(-4) mg 1(-1)). Kinetic parameters for MTBE degradation in the presence or absence of metals were obtained through nonlinear regression and a least-square minimization procedure. In all cases, a good agreement was achieved between kinetic simulations and experimental results. (C) 2007 Elsevier Ltd. All rights reserved.