Table 3.
The effect of acetone and ammonium sulfate precipitation on MCA/PA ratio of MCP from A. oryzae DRDFS13
| Sample | Extraction solvent | Precipitating solvents | MCA (U/mL) Mean ± SD |
PA (U/mL) Mean ± SD |
Ratio (MCA/PA) |
|---|---|---|---|---|---|
| Crude enzyme (0.5% glucose) | 1 M NaCl | – | 168.47 ± 2.96a | 300.80 ± 22.52a | 0.56 |
| Crude enzyme (0.5% glucose) | 1 M NaCl | Acetone | 84.96 ± 1.06c | 65.28 ± 3.07c | 1.30 |
| Crude enzyme (0.5% glucose) | 1 M NaCl | 80% (NH4)2SO4 | 120.19 ± 6.80b | 185.01 ± 0.32b | 0.65 |
| Chymosin | _ | _ | 2533.33 ± 188.56 | 99.76 ± 5.36 | 25.39 |
Chymosin, commercially produced pure enzyme used as positive control; MCA, milk-clotting activity (U/mL); PA, protease activity (U/mL); ratio, the ratio of MCA/PA; SD, standard deviation; mean, average of two measurements; different letters (a, b, c, d) designate significantly different means as determined by Duncan multiple mean comparison test (P < 0.05)