Journal: Applied and Environmental Microbiology
Article Title: Characterization of the Initial Reactions during the Cometabolic Oxidation of Methyl tert-Butyl Ether by Propane-Grown Mycobacterium vaccae JOB5
Figure Lengend Snippet: Kinetics of MTBE and TBA oxidation by propane-grown cells of M. vaccae JOB5. The figure shows the effect of various concentrations of propane on the rate of MTBE and TBA oxidation. Propane-grown cells (∼1 mg of total protein) were incubated for 30 min with a fixed initial concentration of either MTBE (0.9 mM aqueous concentration) or TBA (1 mM aqueous concentration) in the presence of the indicated aqueous concentrations of propane. The aqueous concentrations of propane were estimated from the partial pressure of propane added to the gas phase of the reaction vials by assuming that the small volumes of gas added (≤5% of gas phase) had a negligible effect on the total gas pressure within the reaction vial. The plot shows the percent inhibition of MTBE (○) and TBA (•) consumption at each propane concentration, compared to the amount of each substrate consumed in the absence of propane. The figure shows the resulting curves generated when the values for percent inhibition were fitted by computer, as described in Materials and Methods. The inset shows the rates of MTBE and TBA oxidation by propane-grown cells of M. vaccae JOB5 plotted versus initial substrate concentration. For each datum point, cells (0.8 mg total protein) were incubated with the indicated concentration of MTBE or TBA and the initial rate (0 to 30 min) of substrate consumption was determined by GC, as described in Materials and Methods. The figure shows the resulting curves generated when the calculated rates of substrate consumption for MTBE (▪) and TBA (▴) were fitted by computer, as described in Materials and Methods.
Article Snippet: TBF (97% purity), tert -butyl acetate (TBAc) ( > 99% purity), tert -butyl propionate (TBP) (99% purity), TBA ( > 99% purity), 1-propanol (99.5% purity), 2-propanol (99.5% purity), MTBE (99.8% purity), and calcium carbide ( ∼ 80% purity; for acetylene generation) were obtained from Aldrich Chemical Co., Inc. (Milwaukee, Wis.).
Techniques: Incubation, Concentration Assay, Inhibition, Generated