TABLE 2.
Saturation kinetic values (apparent Vmax and Km) and product distribution for toluene oxidation by E. coli TG1 cells expressing T3MO and T4MO from pBS(Kan)T3MO and pBS(Kan)T4MO, respectively, and toluene product distribution by P. aeruginosa PAO1/pRO1966 expressing T3MO grown under different conditions
| Strain | Growth mediumc | Kinetics of toluene oxidationa
|
Regiospecificity of toluene oxidationb (%)
|
||||
|---|---|---|---|---|---|---|---|
| Apparent Vmax (nmol/min/mg of protein) | Apparent Km (μM) | Vmax/Km | o-Cresol | m-Cresol | p-Cresol | ||
| TG1/pBS(Kan) | LB KAN | 0 | 0 | 0 | |||
| TG1/pBS(Kan)T3MO | LB KAN | 11.5 ± 0.3 | 250 | 0.046 | 0 | 10 | 90 |
| TG1/pBS(Kan)T4MO | LB KAN | 15.1 ± 0.8 | 110 | 0.137 | 0 | 3 | 97 |
| P. aeruginosa PAO1 | LB + toluene | 0 | 0 | 0 | |||
| PAO1/pRO1966 | LB + AMP + toluene | 0 | 10 | 90 | |||
| PAO1/pRO1966 | M9 + AMP + lactate + toluene | 0 | 9 | 91 | |||
| PAO1/pRO1966 | M9 + AMP + succinate + toluene | 0 | 11 | 89 | |||
a
The toluene concentration in the liquid phase was 90 to 700 μM based on Henry's law constant of 0.27 (7) (250 to 1,920 μM added if all the toluene is in the liquid phase). Seven different toluene concentrations were used for each strain.
b
Based on GC analysis over a 20-min period. The initial toluene concentration in the liquid was 90 μM.
c
KAN, kanamycin; AMP, ampicillin.