Table 2.
Studies comprising of the enhancement strategies used for β-glucosidase production.
| S. no. | Strain used and enzymes | Enhancement strategies | Conclusion | Reference |
|---|---|---|---|---|
| 1 | Aspergillus aculeatusβ-glucosidase 1 | A recombinant T. reesei strain, X3AB1 under the control of xyn3 promoter | 63- and 25-fold higher β-glucosidase activity against cellobiose | [38] |
| 2 | β-glucosidase from Periconia spp. | Heterologous expression in T. reesei | Around 10.5-fold (23.9 IU/mg) higher β-glucosidase activity A very high total cellulase activity (about 39.0 FPU/mg) |
[63] |
| 3 | T. reesei, Bgl2 | Mutational studies and engineering of active site residues | Mutants, P172L, and P172L/F250A showed enhanced k
cat/K
m and k
cat values by 5.3- and 6.9-fold Also, mutant L167W had the best synergism with T. reesei in cellulosic biomass degradation |
[32] |
| 4 | T. reesei (bglI) | Overexpression in P. pastoris GS115 under methanol-inducible alcohol oxidase promoter and S. cerevisiae secretory signal peptide. |
β-glucosidase expression was 0.3 mg/mL and the maximum activity was 60 U/mL | [39] |
| 5 | β-glucosidase 1 (BGL1) | Use of xyn3 and egl3 promoters through homologous recombination |
4.0- and 7.5-fold higher β-glucosidase activity | [70] |
| 6 | T. citrinoviride mutants | Mutational studies, use of ethidium bromide and ethyl methyl sulphonate as mutagens | Secretion of endoglucanase, β-glucosidase and cellobiase was found to be 2.14-, 2.10-, 4.09-, and 1.73-fold higher | [28] |
| 7 | Thermostable β-glucosidase (cel3a) | cel3a from Talaromyces emersonii was expressed in T. reesei | High specific activity against p-nitrophenyl-β-D-glucopyranoside (V max, 512 IU/mg) and was competitively inhibited by glucose (ki, 0.254 mM) and displayed transferase activity | [40] |
| 8 | BGL4 from H. grisea | Overexpression of BGL4 in T. reesei or T. viride |
Improvement in cellulose saccharification by 1.4–2.2 times | [43] |
| 9 | T. reesei Rut C-30 | Temperature and pH profiling studies | 0.02% Tween-80 concentration was optimum, pH 5.0 and temperature (31°C) initially (for 18 h) was optimum for maximum production of cellulase and β-glucosidase | [89] |