TABLE 5.
Activity of NADP-dependent isocitrate dehydrogenasea
| Carbon source (concn [mM]) | ΔmclA NADP-IDH (U/mg) | Factor of induction | WT NADP-IDH (U/mg) | Factor of induction | Ratio (ΔmclA/WT) |
|---|---|---|---|---|---|
| Glucose (50) | 0.12 | 1.0 | 0.082 | 1.0 | 1.5:1 |
| Glucose (50), propionate (20) | 0.87 | 7.3 | 0.22 | 2.7 | 4.0:1 |
| Glucose (50), propionate (50) | 1.10 | 9.2 | 0.25 | 3.0 | 4.4:1 |
| Glucose (50), acetate (20) | 0.20 | 1.6 | 0.31 | 3.8 | 1:1.6 |
| Glucose (50), acetate (50) | 0.28 | 2.2 | 0.40 | 4.9 | 1:1.4 |
| Acetate (100) | 1.05 | 1.0 | 0.67 | 1.0 | 1.6:1 |
| Acetate (100), propionate (20) | 1.27 | 1.2 | 0.66 | 1.0 | 1.9:1 |
| Acetate (100), propionate (50) | 1.23 | 1.2 | 0.66 | 1.0 | 1.9:1 |
| Glycerol (50) | 0.217 | 1.0 | 0.082 | 1.0 | 2.6:1 |
| Glycerol (50), propionate (5) | 1.56* | 7.2 | 0.29 | 3.5 | 5.4:1 |
a
Wild-type and methylisocitrate lyase mutant were incubated for the same time as indicated for the determination of growth inhibition. An exception is marked with an asterisk, where the mutant strain was incubated for 72 h in order to yield sufficient biomass. Numbers in parentheses indicate the molarity of the carbon sources. The factor of induction is calculated with respect to the value of the corresponding sole carbon source: glucose, acetate, or glycerol. Specific activities were calculated from three independent determinations, with an average error of <5%. IDH, isocitrate dehydrogenase.