Table 4. Effect of organic solvents on the activity and stability of purified LacA.
| Organic solvent | Concentration (%) | Relative Activitya (%) | Residual Activityb (%) |
| Methanol | 5 | 92.9±5.3 | 92.7±1.1 |
| 10 | 72.7±6.7 | 107.7±3.1 | |
| 25 | 57.3±6.9 | 116.5±5.9 | |
| Ethanol | 5 | 101.0±4.7 | 94.0±7.2 |
| 10 | 83.1±2.9 | 101.0±4.5 | |
| 25 | 70.9±3.5 | 100.2±3.0 | |
| Acetonitrile | 5 | 102.5±4.2 | 105.0±2.8 |
| 10 | 96.8±1.9 | 95.9±5.1 | |
| 25 | 66.2±2.0 | 50.4±2.6 | |
| DMSO | 5 | 91.1±2.1 | 98.1±4.7 |
| 10 | 77.3±4.4 | 116.8±3.1 | |
| 25 | 58.7±1.8 | 124.9±2.4 | |
| DMF | 5 | 95.1±3.7 | 95.9±2.1 |
| 10 | 82.5±2.5 | 100.7±0.9 | |
| 25 | 78.9±2.8 | 94.4±1.3 |
Values represent mean ± standard deviation (n = 3).
a
Enzyme activity was measured with individual organic solvent included in the enzyme activity assay mixture at the concentration indicated.
b
Purified LacA was incubated with individual organic solvent at the concentration indicated for 4 hours at 25°C before the standard enzyme activity assay was conducted.