TABLE 12.
Thermophilic and hyperthermophilic enzymes with potential industrial applications
| Enzyme | Origin | Potential application(s) | Properties | Reference(s) |
|---|---|---|---|---|
| Endo-1,4-β-glucanase | T. maritima | Cellulose degradation | Optimal activity at 95°C, pH 6.0–7.5; t1/2, 2 h (95°C) | 42, 218 |
| T. neapolitana | Cellulose degradation | Optimal activity at 95°C, pH 6.0; sp act, 1,219 U/mga on CMCb | 32 | |
| T. neapolitana | Cellulose degradation | Optimal activity at 106°C, pH 6.0–6.6; sp act: 1,536 U/mg on CMC; t1/2, 130 min(106°C); transglycosylation activity | 32 | |
| Cellobiohydrolase | T. maritima | Cellulose degradation | Optimal activity at 95°C, pH 6.0–7.5; t1/2, 30 min (95°C) | 42 |
| Cellobiohydrolase | Thermotoga sp. strain FjSS3-B.1 | Cellulose degradation | Optimal activity at 105°C. pH 7.0; t1/2, 70 min (108°C) | 286 |
| Endoxylanase | Thermotoga sp. strain FjSS3-B.1 | Paper pulp bleaching | Optimal activity at pH 6.5; t1/2, 22 h (90°C) and 12 h (95°C) | 294 |
| T. thermarum (enzyme II) | Paper pulp bleaching | Optimal activity at 90–100°C, pH 7.0; sp act, 19.5 U/mg; inactive on CMC | 324 | |
| Thermoanaerobacterium saccharolyticum | Paper pulp bleaching | Optimal activity at 70°C, pH 5.5–6.0; t1/2, 35 min (80°C) | 208,207 | |
| Bacillus sp. strain 3D | Paper pulp bleaching | Optimal activity at 75°C, pH 6.0 (3,300 U/mg); stable at 80°C for 24 h (pH 9.0) and 10 h (pH 12.5) | 126 | |
| β-Xylosidase/ arabinofuranosidase | Thermotoga sp. strain FjSS3-B.1 | Paper pulp bleaching | Optimal activity at pH 7.0; t1/2, 4 h (98°C) (+ 40 mg of bovine serum albumin per ml) | 285, 287 |
| β-Mannanase | Rhodothermus marinus | Softwood pulp bleaching; coffee bean treatment and coffee extraction | Optimal activity at 85°C, pH 5.0–6.5; t1/2, 45.3 h (85°C) and 4.2 h (90°C) | 118 |
| β-Xylosidase | Thermoanaerobacterium saccharolyticum | Carbohydrate synthesis; xylose production | Optimal activity at 70°C, pH 5.5; t1/2, 55 min (75°C); β-1,4, β-1,3, and β-1,1 transglycosylation activities | 11, 209 |
| β-Glucosidase | P. furiosus | Regio- and stereoselective glucoconjugate synthesis by transglycosylation | Optimal activity at 102–105°C, pH 5.0; Km of 20 mM and Vmax of 470 U/mg (95°C) on cellobiose; t1/2, 85 h (100°C) and 13 h (110°C) | 176 |
| Trehalose synthase | Thermus caldophilus | α, α-Trehalose production; used in food, cosmetics, medicine, and organ preservation | Producs 86% α, α-trehalose from 95% maltose at 40°C | 189 |
| Hydantoinase | Bacillus stearothermophilus | Synthesis of d-amino acids as intermediates in the production of semi-synthetic antibiotics, peptide hormones, pyrethroids, and pesticides | Optimal activity at 65°C, pH 8.0 (+ Mn2+); t1/2, 30 min (80°C) | 206 |
| Esterase | P. furiosus | Transesterification and ester synthesis | Optimal activity at 100°C, pH 7.6; t1/2, 34 h (100°C) and 2 h (120°C) | 157 |
| Aldolase | S. solfataricus | Synthetic chemistry: C—C bond synthesis | Specific for nonphosphorylated substrates; Optimal activity at 90°C; t1/2, 7.8 h (90°C) and 2.5 h (100°C) | 45 |
| Cytochrome P450 | S. solfataricus | Selective regio- and stereospecific hydroxylations in chemical synthesis | Tm, 91°C; substrate unknown | 242 |
| Secondary alcohol dehydrogenase | Thermoanaerobacter ethanolicus | Chemical synthesis: production of enantiomerically pure chiral alcohols | Optimal activity at >90°C; t1/2, 1.7 h (90°C) | 46, 47, 339 |
| Pectin methylesterase | T. thermosulfurigenes | Fruit juice clarification, wine making | Optimal activity at 70°C, pH 6.5; t1/2, 30 min (70°C) | 296 |
| Polygalacturonate hydrolase | T. thermosulfurigenes | Fruit juice clarification, wine making | Optimal activity at 75°C, pH 5.5; t1/2, 30 min (70°C) | 296 |
| Pectate lyase | Thermoanaerobacter italicus | Fruit juice clarification, wine making, fruit and vegetable maceration | Optimal activity at 80°C; stable at 70°C for 2 h | 194 |
| β-Galactosidase | T. maritima | Production of lactose-free dietary milk products | Optimal activity at 80°C, pH 5.3 | 111 |
| β-Fructosidase | T. maritima | Confectionery industry; production of invert sugar; hydrolysis of inulin to produce HFCS | Optimal activity at 90–95°C, pH 5.5; no metal requirement; hydrolyzes sucrose (no product inhibition) and inulin | 217 |
| β-1,4-Endoglucanase | P. furiosus | Animal feed: digestion of barley β-glucan | Hydrolyzes β-1,4 linkages in (1→3),(1→4)-β-d-glucans and cellulose; optimal activity at 100°C, pH 6.0; t1/2, 40 h (90°C) and 1.6 h (105°C) | 20 |
| Phytase | Bacillus sp. strain DS11 | Phytate degradation in animal feed | Optimal activity at 70°C, pH 5.0–5.5; t1/2, 10 min (90°C) (+ 5 mM CaCl2) | 178 |
| Keratinase | Fervidobacterium pennavorans | Degradation of poultry feathers and production of rare amino acids (i.e., serine and proline) | Optimal activity at 80°C, pH 10.0 | 105 |
| Chitinase | Streptomyces thermoviolaceus | Chitin utilization as a renewable resource; production of biologically active oligosaccharides | Optimal activity at 80°C, pH 9.0; transglycosylation activity | 340 |
| α-Galactosidase | T. maritima | Oil and gas industry: well stimulation by galactomannan hydrolysis; sugar beet processing: removal of raffinose from sucrose syrups; oligosaccharide synthesis through glycosyl transfer reactions | Optimal activity at 90–95°C, pH 5.0–5.5; t1/2, 48 h (80°C) and 70 min (90°C); hydrolyzes raffinose and melibiose | 219 |
| Alkaline phosphatase | T. neapolitana | Diagnostics: enzyme-labeling applications where high stability is required | Optimal activity at 85°C, pH 9.9; t1/2, 4 h (90°C) (+ Co2+); Sp act, 1,352 U/mg (85°C) with pNPPb as substrate | 87 |
a
1 U corresponds to an OD430 change of 0.1/min.
b
CMC, carboxymethyl cellulose.
c
pNPP, p-nitrophenyl phosphate.