Enzymatic Hydrolysis of Softwood Derived Paper Sludge by an In Vitro Recombinant Cellulase Cocktail for the Production of Fermentable Sugars
Abstract
:1. Introduction
2. Results and Discussion
2.1. Composition and Structural Analysis of Paper Sludge
2.2. Enzyme Production and Substrate Specificities Using “Model” Substrates
2.3. Enzyme Cocktail Formulation
2.4. Effect of Opt CelMix Loading on the Hydrolysis Yields of Paper Sludge
2.5. Scanning Electron Microscopy (SEM)
2.6. Evaluation of the Performance of the Opt CelMix at Varying Paper Sludge Loadings
2.7. Comparison of the Hydrolytic Efficiency of the Opt CelMix to Commercial Cellulase Preparations
3. Materials and Methods
3.1. Materials
3.2. Paper Sludge Moisture Content Determination
3.3. Paper Sludge Chemical Composition
3.4. Paper Sludge Crystallinity Index (CrI)
3.5. Simon’s Staining (SS) of Paper Sludge
3.6. Media, Yeast Strains and Culture Conditions
3.7. Preparation of Partially Purified Enzymes
3.8. Protein Content and Purity Determination
3.9. Enzyme Assays
3.9.1. Substrate Specificity Determination
3.9.2. Enzyme Cocktail Formulation
3.9.3. Effect of Cellulase Cocktail Loading on the Hydrolysis Yields of Paper Sludge
3.9.4. Effect of Paper Sludge Loading on Cellulase Cocktail Hydrolytic Efficiency
3.9.5. Comparison of the Formulated Cellulase Cocktail to Commercial Enzyme Preparations
3.10. Analytical Methods
3.11. Scanning Electron Microscopy (SEM)
3.12. Statistical Analysis
4. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Component/Property | Content/Accessibility |
---|---|
Glucan * | 89.7% |
Mannan * | 2.73% |
Xylan * | 1.65% |
Galactan * | 0.08% |
Arabinan * | Nd |
Lignin * | 0.8% |
Ash * | 1.7% |
Moisture | 74.3% |
Crystallinity index | 91.5% |
Substrate accessibility (mg/g) | 87 mg/g |
Enzyme | CMC-Na | Cellopentaitol | pNPC | pNPG | Reference |
---|---|---|---|---|---|
BGL | 0.67 | - | 5.74 | 56 | [10,14,25] |
CBHI | 0.24 | Nd | 0.20 | 0.35 | [12,26] |
CBHII | 1.69 | 0.38 | Nd | 0.11 | [26] |
EGII | 44 | - | Nd | 0.11 | [10,12,14,26] |
No | CBHI% | CBHII% | EGII% |
---|---|---|---|
1. | 100 | 0 | 0 |
2. | 75 | 25 | 0 |
3. | 50 | 50 | 0 |
4. | 25 | 75 | 0 |
5. | 0 | 100 | 0 |
6. | 0 | 75 | 25 |
7. | 0 | 50 | 50 |
8. | 0 | 25 | 75 |
9. | 0 | 0 | 100 |
10. | 25 | 0 | 75 |
11. | 50 | 0 | 50 |
12. | 75 | 0 | 25 |
13. | 33.3 | 33.3 | 33.3 |
14. | 33.5 | 33.5 | 25 |
15. | 12.5 | 12.5 | 75 |
16. | 18.75 | 56.25 | 25 |
17. | 56.25 | 18.75 | 25 |
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Malgas, S.; Rose, S.H.; van Zyl, W.H.; Pletschke, B.I. Enzymatic Hydrolysis of Softwood Derived Paper Sludge by an In Vitro Recombinant Cellulase Cocktail for the Production of Fermentable Sugars. Catalysts 2020, 10, 775. https://doi.org/10.3390/catal10070775
Malgas S, Rose SH, van Zyl WH, Pletschke BI. Enzymatic Hydrolysis of Softwood Derived Paper Sludge by an In Vitro Recombinant Cellulase Cocktail for the Production of Fermentable Sugars. Catalysts. 2020; 10(7):775. https://doi.org/10.3390/catal10070775
Chicago/Turabian StyleMalgas, Samkelo, Shaunita H. Rose, Willem H. van Zyl, and Brett I. Pletschke. 2020. "Enzymatic Hydrolysis of Softwood Derived Paper Sludge by an In Vitro Recombinant Cellulase Cocktail for the Production of Fermentable Sugars" Catalysts 10, no. 7: 775. https://doi.org/10.3390/catal10070775