TABLE 3.
Total protein contents and estimated SI protein contents in E. coli cells expressing cloned SI genesa
| SI gene source | Total protein (%, dry wt) | Total SI (% of cellular proteins)b | Soluble His-tagged SI
|
Amt of isomaltulose produced (μmol)d | Cellular soluble SI efficiency (mol of isomaltulose g of SI−1) | |
|---|---|---|---|---|---|---|
| % of total SI | Concn (μg ml−1)c | |||||
| E. rhapontici WAC2928 | 16.0 ± 1.6 | 10.2 ± 1.5 | 26.5 | 129.3 | 511 ± 65 | 4 |
| K. planticola UQ14S | 15.8 ± 1.4 | 9.8 ± 0.5 | 2.7 | 12.2 | 292 ± 67 | 24 |
| P. dispersa UQ68J | 16.1 ± 1.8 | 10.4 ± 1.2 | 8.1 | 36.4 | 5552 ± 212 | 152 |
| Control (pET24b) | 14.4 ± 2.0 | 0 | 0 | 0 | 0 | |
a
The data are means ± standard errors for three replicates.
b
Corrected for 2% proteins in the PAGE SI zone of the control crude lysates.
c
Amount of SI recovered from batch adsorption to Ni-NTA agarose per milliliter of IPTG-induced culture.
d
Amount of isomaltulose produced in the cellular assay per milliliter of IPTG-induced culture.