TABLE 3.
Growth of C. glutamicum strains with deletions in ssu and seu genes on different classes of sulfonates and sulfonate estersa
| Compound | Growth of strains
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Wild type | ΔssuA or ΔssuB or ΔssuC (transporter)b,c | ΔssuD1 (monooxy- genase)c | ΔssuD2 (monooxy- genase)c | ΔssuD1 ΔssuD2 (monooxy- genases)c,d | ΔseuA or ΔseuB (monooxy- genase)b,c | ΔseuC (monooxy- genase)c | ΔssuD1 ΔssuD2 ΔseuABC (monooxy- genases)c,d | ΔssuI (reductase)c | |
| Inorganic sulfur compounds | |||||||||
| Sulfate, sulfite | + | + | + | + | + | + | + | + | + |
| Sulfonates | |||||||||
| Simple aliphatic sulfonates (e.g., ethanesulfonate) | + | − | + | + | − | + | + | − | − |
| Long-chain simple aliphatic sulfonates (e.g., octanesulfonate) | + | + | + | + | − | + | + | − | − |
| Organic buffers (e.g., MOPS) | + | − | + | + | − | + | + | − | − |
| Aliphatic sulfonates with additional group (e.g., taurine) | + | − | —e | + | − | + | + | − | − |
| Sulfonate esters | |||||||||
| Busulfan | + | + | + | + | + | + | + | − | − |
| Butanesultone | + | + | + | + | + | − | + | − | − |
| (S)-1,2,4-Butanetriol-trimethane-sulfonate | + | − | + | + | − | + | + | − | − |
| Ethyl methanesulfonate | + | + | + | + | + | + | + | − | − |
| l-(−)-Methanesulfonylethyllactate | + | + | + | + | + | + | + | − | − |
| Methyl methanesulfonate | + | + | + | + | + | + | + | − | − |
| Propanesultone | + | − | + | + | − | + | + | − | − |
a
+, compound can be used as a sole sulfur source; −, growth was the same as the growth with no added sulfur after 72 h of incubation at 30°C. The test substances are shown in Fig. 1. Only compounds that could be utilized as sulfur sources by the wild type were used for the growth tests.
b
Strains having a deletion in any of the genes had the same phenotype.
c
The data in parentheses are the proposed functions of the deleted genes.
d
A strain having multiple deletions was constructed and tested.
e
Deletion of ssuD1 resulted in a mutant able to utilize all sulfonates except l-cysteic acid, 1,2-ethanedisulfonate, and sulfoacetate.