TABLE 3.
Comparison of promoters for EGZ production and secretion in E. coli B
| Plasmida | Without secretion genes
|
With secretion genes (pCPP2006)
|
||
|---|---|---|---|---|
| Total activity (IU/liter)b | Extracellularc activity (%) | Total activity (IU/liter) | Extracellularc activity (%) | |
| Low copy number | ||||
| pLOI2173 | 620 | 17 | 1,100 | 43 |
| pLOI2177 | 3,700 | 10 | 5,500 | 44 |
| pLOI2178 | 2,200 | 9 | 3,500 | 49 |
| pLOI2179 | 2,000 | 10 | 3,000 | 50 |
| pLOI2180 | 2,900 | 8 | 6,300 | 39 |
| pLOI2181 | 1,800 | 11 | 4,100 | 46 |
| pLOI2182 | 3,500 | 7 | 6,600 | 38 |
| pLOI2183 | 3,400 | 7 | 6,900 | 39 |
| pLOI2184 | 2,100 | 12 | 2,400 | 39 |
| High copy number | ||||
| pLOI2164 | 3,200 | 20 | 6,900 | 74 |
| pLOI2307 | 6,600 | 28 | 13,000 | 60 |
a
Plasmids pLOI2173 and pLOI2164 contain the celZ native promoter; pLOI2307 contains the strong promoter from pLOI2183. Plasmids pLOI2164 and pLOI2307 are pUC-based plasmids (high copy number). All other plasmids are derivatives of pST76-K (low copy number).
b
Endoglucanase activities were determined after 16 h of growth at 30°C.
c
Extracellular activity (secreted or released).