Table 2.

Amylase activities of whole-membrane extracts of various strainsa

B. thetaiotaomicronstrainPhenotypebAmylase activity (U/mg of cell protein [10−3]c)
5482 (wild type)A+B+ C+ D+ E+F+ G+ 4,204
5482 grown on glucoseA+ B+ C+ D+E+ F+ G+ <50
ΩsusA A B+ C+D+ E+ F+ G+ 690
ΩSAGA B+ C+D+ E+ F+ G <50
ΩSAG(pSGC23A)A B+ C+D+ E+ F+ G++ 1,665
ΩSACA B+ CD E F G
ΩSAC(pSGC23A)A B+ CD E FG++ 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 wasp-nitrophenyl-α-d-maltoheptaoside.