Table 2.
Characterized exoglucanases (1,4-β-cellobiosidase) acting on non-reducing ends from thermophiles (EC 3.2.1.91). NM: not measured.
| Enzyme | GH Family Domains | Optimum Temperature | Optimum pH | Temperature Stability 1 | Source | Reference |
|---|---|---|---|---|---|---|
| CBHII | 6 | 60 °C | 4.0 | 30%; 100 °C; 10 min | Bacteria (Streptomyces sp. M23) | [106] |
| Cel6B | 6 | NM | 7.0–8.0 | 100%; 55 °C; 16 h | Bacteria (Thermobifida fusca) | [107] |
| CBHII | 6 | 57 °C | 5.5 | NM | Fungi (Aspergillus nidulans) | [78] |
| Cel6A | 6 | 50 °C | 4.0 | 50%; 70 °C; 30 min | Fungi (Chaetomium thermophilum) | [108] |
| CBHII (Cel6A) | 6 | 60 °C | 5.0–5.5 | >90%; 50 °C; 5 h | Fungi (Chrysosporium lucknowense) | [109] |
| HiCel6A | 6 | 60–65 °C | NM | 50%; 75 °C; <25 min | Fungi (Humicola insolens) | [26] |
| Ex-4 | 6 | 50 °C | 5.0 | 80%; 60 °C; 60 min | Fungi (Irpex Lacteus) | [110] |
| PoCel6A | 6 | 50 °C | 5.0 | 90%; 50 °C; 2 h 80%; 60 °C; 4 h |
Fungi (Penicillium oxalicum) | [111] |
| PaCel6A | 6 | 55 °C | 5.0–9.0 | 100%; 35 °C; 24 h >20%; 45 °C; 24 h |
Fungi (Podospora anserina) | [19] |
| CBHII | 6 | 70 °C | 5.0 | NM | Fungi (Trichoderma viride) | [112] |
| G10-6 | 6 | 55 °C | 9.5 | NM | Uncultured organism (Eathworm casts metagenome) | [70] |
| Cbh9A | 9 | 60 °C | 6.5 | NM | Bacteria (Ruminiclostridium thermocellum) | [113] |
| Cel9K | 9 | 65 °C | 6.0 | 97%; 60 °C; 200 h | Bacteria (Ruminiclostridium thermocellum) | [114] |
1 Temperature stability is given as a percentage of activity (residual activity) after treatment at the specified temperature and time compared to the untreated enzyme.