Table 4.
Dioxygenase activities in cell-free extracts from Stenotrophomonas maltophilia KB2 grown on 3 mM aromatic compounds. Catechol was used as substrate in the reaction mixture for detection of catechol dioxygenase activities and protocatechuate - for protocatechuate dioxygenases. The results are an average of at least three independent measurements.
| Inductor | Specific activity µmol min.-1 mg-1 of protein | |||
|---|---|---|---|---|
| Catechol 1,2-dioxygenase | Catechol 2,3-dioxygenase | Protocatechuate 3,4-dioxygenase | Protocatechuate 4,5-dioxygenase | |
| Phenol | 0.06 ± 0.02 | 4.92 ± 0.34 | NDa | ND |
| Catechol | 1.03 ± 0.01 | 0.37 ± 0.00 | ND | ND |
| 4-HB | ND | ND | 6.37 ± 0.72 | ND |
| 3,4-DHB | ND | 0.01 ± 0.00 | 2.98 ± 0.72 | ND |
| Vanillic acid | 0.12 ± 0.03 | 0.04 ± 0.02 | 8.70 ± 1.36 | ND |
| Benzoic acid | 11.97 ± 3.04 | 0.02 ± 0.01 | ND | ND |
| Glucose | ND | ND | ND | ND |
a
ND - not detected; 4-HB - 4-hydroxybenzoic acid; 3,4-DHB - 3,4-dihydroxybenzoic acid.