TABLE 2.
Amylase activities of whole-membrane extracts of various strainsa
| B. thetaiotaomicron strain | Phenotypeb | Amylase activity (U/mg of cell protein [10−3]c) |
|---|---|---|
| 5482 (wild type) | A+ B+ C+ D+ E+ F+ G+ | 4,204 |
| 5482 grown on glucose | A+ B+ C+ D+ E+ F+ G+ | <50 |
| ΩsusA | A− B+ C+ D+ E+ F+ G+ | 690 |
| ΩSAG | A− B+ C+ D+ E+ F+ G− | <50 |
| ΩSAG(pSGC23A) | A− B+ C+ D+ E+ F+ G++ | 1,665 |
| ΩSAC | A− B+ C− D− E− F− G− | |
| ΩSAC(pSGC23A) | A− B+ C− D− E− F− G++ | 1,113 |
a
For this assay, all strains were grown on minimal medium plus maltose except as indicated. Variation between replicate samples was less than 10%.
b
Production of Sus proteins in each strain. For example, “A” corresponds to production of SusA. ++ indicates twofold-higher expression than in the wild type.
c
Units are in micromoles per minute. The substrate used to detect amylase activity was p-nitrophenyl-α-d-maltoheptaoside.