Table 5.
Para-nitrophenyl release by TrCel7A or TrCel7A core from pNP-lac at 50°C and 30°C in the presence of phosphoric acid swollen cellulose
| Enzyme, temperature substrate | Control | 1 g/L low XOS | 1 g/L high XOS |
|---|---|---|---|
|
TrCel7A core, 50°C pNP-laca (PASC) |
25 ± 2 μM pNP 20% of total activity |
15 ± 4 μM pNP 12% of total activity |
9 ± 1 μM pNP 8% of total activity |
|
TrCel7A, 50°C pNP-lac (PASC) |
6 ± 1 μM pNP 7% of total activity |
5 ± 1 μM pNP 5% of total activity |
< 4 μM pNPb |
|
TrCel7A core, 30°C pNP-lac (PASC) |
6 ± 1 μM pNP 12% of total activity |
< 4 μM pNPb | < 4 μM pNPb |
|
TrCel7A, 30°C pNP-lac (PASC) |
< 4 μM pNPb | < 4 μMb | < 4 μM pNPb |
PASC = phosphoric acid swollen cellulose; pNP = para-nitrophenyl; pNP-lac = para-nitrophenyl-β-D-lacoside; TrCel7A = cellobiohydrolase I; XOS = xylan oligosaccharide. The percentages were calculated on the basis of the total pNP activity shown in Table 3. The deviations are the standard deviations of five independent experiments. aThe Ki for cellobiose in the pNP-lac assay is 20 μM, which is exceeded here. The activities are underestimated. bThe detected absorbance changes were below 0.02 absThe activities were too low for reliable quantification.