TABLE 10.
Examples of thermophilic and hyperthermophilic enzymes with potential applications in starch processing
| Enzyme | Origin | Properties | Reference |
|---|---|---|---|
| α-Amylase | Desulfurococcus mucosus | Optimal activity at 100°C, pH 5.5a | 56 |
| Pyrococcus furiosus | Optimal activity at 100°C, pH 5.5–6.0; sp act, 3,900 U/mg (98°C); t1/2, 13 h (98°C) | 85 | |
| Pyrococcus woesei | Optimal activity at 100°C, pH 5.5 | 188 | |
| Pyrodictium abyssi | Optimal activity at 100°C, pH 5.0 | 263 | |
| Staphylothermus marinus | Optimal activity at 100°C, pH 5.0a | 56 | |
| Thermococcus profundus | Optimal activity at 80°C, pH 4.0–5.0 | 65, 205 | |
| Dictyoglomus thermophilum | Optimal activity at 90°C, pH 5.5 | 109 | |
| Thermotoga maritima | Optimal activity at 85–90°C, pH 7.0 | 263 | |
| Pullulanase | Bacillus flavocaldarius | Optimal activity at 75–85°C, pH 6.3; t1/2, 10 min (107°C) | 170, 325 |
| Thermotoga maritima | Optimal activity at 90°C, pH 6.0 | 263 | |
| Thermus caldophilus | Optimal activity at 75°C, pH 5.5; t1/2, 72 h (78°C, pH 6.0) | 177 | |
| Fervidobacterium pennavorans | Optimal activity at 80–85°C, pH 6.0; t1/2, 2 h (80°C) and > 50 h (80°C + starch) | 27, 187 | |
| Amylopullulanase | Desulfurococcus mucosus | Optimal activity at 100°C, pH 5.0a | 56 |
| ES4 | Optimal activity on starch at 120°C, pH 5.5–6.5; t1/2, 6.5 h (98°C) and 20 h (98°C) (+CaCl2) | 298 | |
| Pyrococcus furiosus | Optimal activity at 105°C, pH 6.0; Vmax(starch), 88 U/mg (98°C), t1/2, 44 h (90°C) (5 mM CaCl2) | 86 | |
| Thermococcus celer | Optimal activity at 90°C, pH 5.5a | 56 | |
| Thermococcus litoralis | Optimal activity at 117°C, pH 5.5 (5 mM CaCl2) | 43 | |
| Thermococcus hydrothermalis | t1/2, >8 h (95°C) and 1 h (105°C) | 97, 113 | |
| Thermoanaerobacter ethanolicus | Optimal activity at 90°C, pH 5.5; sp act (starch), 175 U/mg (60°C); t1/2, 40 min (90°C) | 235, 236 | |
| Glucoamylase | Clostridium thermosaccharolyticum | Optimal activity at 70°C, pH 5.0; >90% active after 6 h (70°C) | 312 |
| Methanococcus jannaschii | Putative gene identified in the genome sequence | 21 | |
| Thermoanaerobacterium thermosaccharolyticum | Optimal activity at 50–60°C, pH 4.0–5.5; stable for 8 h (65°C) | 112 | |
| α-Glucosidase | Thermoanaerobacter ethanolicus | Optimal activity at 75°C, pH 5.0–5.5; t1/2, 46 h (60°C) and 35 min (75°C) | 288 |
| β-Amylase | Thermotoga maritima | Optimal activity at 95°C, pH 4.3–5.5; t1/2, ca. 30 min (90°C) | 300 |
| Thermoanaerobacterium thermosulfurigenes | Optimal activity at 75°C, pH 5.5–6.0; stable at pH 3.5–6.5; >80% active after 1 h (75°C) | 154, 304 | |
| CGTase | Thermococcus sp. | Optimal activity at 90–100°C, pH 5.0–5.5 (can work at pH 4.5); sp act in CD synthesis, 1,400 U/mg (90°C) (between 69 and 90% α-CD formed); t1/2, 40 min (110°C) | 326 |
| Xylose isomerase | Thermoanaerobacterium thermosulfurigenes | Optimal activity at 80°C, pH 7.5; t1/2, 35 min (85°C) | 204, 244 |
| Thermoanaerobacterium strain JW/SL-YS 489 | Optimal activity at 80°C, pH 6.8; t1/2, 1 h (80°C) | 221 | |
| Thermus aquaticus | Optimal activity at 85°C, pH 7.0; t1/2, 4 days (70°C) | 210 | |
| Thermotoga maritima | Optimal activity at 100–110°C; t1/2, 10 min (120°C) | 44 | |
| Thermotoga neapolitana | Optimal activity at 97°C, pH 7.1; t1/2, 2.5 h (80°C) | 137, 313, 350 |
a
Data obtained with crude enzyme (either culture supernatant or cell extract).