Table 10.

Examples of thermophilic and hyperthermophilic enzymes with potential applications in starch processing

EnzymeOriginPropertiesReference
α-AmylaseDesulfurococcus mucosusOptimal activity at 100°C, pH 5.5a56
Pyrococcus furiosusOptimal 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 woeseiOptimal activity at 100°C, pH 5.5188
Pyrodictium abyssiOptimal activity at 100°C, pH 5.0263
Staphylothermus marinusOptimal activity at 100°C, pH 5.0a56
Thermococcus profundusOptimal activity at 80°C, pH 4.0–5.065, 205
Dictyoglomus thermophilumOptimal activity at 90°C, pH 5.5109
Thermotoga maritimaOptimal activity at 85–90°C, pH 7.0263
PullulanaseBacillus flavocaldariusOptimal activity at 75–85°C, pH 6.3;t1/2, 10 min (107°C)170, 325
Thermotoga maritimaOptimal activity at 90°C, pH 6.0263
Thermus caldophilusOptimal activity at 75°C, pH 5.5; t1/2, 72 h (78°C, pH 6.0)177
Fervidobacterium pennavoransOptimal activity at 80–85°C, pH 6.0;t1/2, 2 h (80°C) and > 50 h (80°C + starch)27, 187
AmylopullulanaseDesulfurococcus mucosusOptimal activity at 100°C, pH 5.0a56
ES4Optimal 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 furiosusOptimal 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 celerOptimal activity at 90°C, pH 5.5a56
Thermococcus litoralisOptimal activity at 117°C, pH 5.5 (5 mM CaCl2)43
Thermococcus hydrothermalist1/2, >8 h (95°C) and 1 h (105°C)97, 113
Thermoanaerobacter ethanolicusOptimal activity at 90°C, pH 5.5; sp act (starch), 175 U/mg (60°C); t1/2, 40 min (90°C)235, 236
GlucoamylaseClostridium thermosaccharolyticumOptimal activity at 70°C, pH 5.0; >90% active after 6 h (70°C)312
Methanococcus jannaschiiPutative gene identified in the genome sequence21
Thermoanaerobacterium thermosaccharolyticumOptimal activity at 50–60°C, pH 4.0–5.5; stable for 8 h (65°C)112
α-GlucosidaseThermoanaerobacter ethanolicusOptimal activity at 75°C, pH 5.0–5.5;t1/2, 46 h (60°C) and 35 min (75°C)288
β-AmylaseThermotoga maritimaOptimal activity at 95°C, pH 4.3–5.5; t1/2, ca. 30 min (90°C)300
Thermoanaerobacterium thermosulfurigenesOptimal 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
CGTaseThermococcus 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 isomeraseThermoanaerobacterium thermosulfurigenesOptimal activity at 80°C, pH 7.5;t1/2, 35 min (85°C)204, 244
Thermoanaerobacterium strain JW/SL-YS 489Optimal activity at 80°C, pH 6.8; t1/2, 1 h (80°C)221
Thermus aquaticusOptimal activity at 85°C, pH 7.0; t1/2, 4 days (70°C)210
Thermotoga maritimaOptimal activity at 100–110°C; t1/2, 10 min (120°C)44
Thermotoga neapolitanaOptimal 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).