Table 2.
Thiol levels in wild-type M. smegmatis mc2155 and mshA mutants
Strain or genotype and growth phasea | Mean level ± SD (μmol/g [dry wt], n = 3) |
|||||
---|---|---|---|---|---|---|
MSH | Cysteine | Coenzyme A | Lipoic acidb | Lipoamideb | Ergothioneine | |
mc2155 | ||||||
Exponential | 8.8 ± 0.2 | 0.080 ± 0.005 | 1.8 ± 0.1 | <0.001 | <0.001 | 0.053 ± 0.01 |
Stationary | 2.4 ± 0.3 | 0.043 ± 0.004 | 1.2 ± 0.1 | ND | ND | 0.11 ± 0.002 |
mshA::Tn5 | ||||||
Exponential | <0.003 | 0.082 ± 0.004 | 1.4 ± 0.1 | <0.001 | <0.001 | 1.4 ± 0.1 |
Stationary | <0.003 | 0.027 ± 0.001 | 1.0 ± 0.3 | ND | ND | 0.52 ± 0.02 |
mshA(G32D) | ||||||
Exponential | <0.003 | 0.095 ± 0.004 | 1.8 ± 0.2 | <0.003 | <0.003 | 1.85 ± 0.020 |
Stationary | <0.003 | 0.057 ± 0.007 | 1.2 ± 0.2 | ND | ND | 0.85 ± 0.06 |
In the exponential phase, growth was at 37°C in liquid Middlebrook 7H9 medium, 1% glucose, 0.05% Tween 80 for 16 h (A600 ∼ 1). In the stationary phase, growth was as for exponential growth but for 48 h (A600 > 2.5).
Unbound forms. ND, not determined.