Table 3.

Catabolite repression of β-xylosidase by different carbon sources in various mutants

Carbon sourceaEnzyme activity in units/mg of proteinb
GP270 ΔxylRGP853 ΔxylR ΔccpAGP284 ΔxylR ptsH1GP297 ΔxylR ΔcrhGP289 ΔxylR ΔhprKGP287 ΔxylR Δcrh ptsH1
None (CSE)1,535 (204)2,548 (179)1,535 (91)2,609 (413)2,414 (445)2,644 (321)
Glucose59 (2)2,074 (43)154 (29)75 (16)2,036 (209)2,385 (48)
Malate170 (27)1,388 (49)176 (28)370 (35)1,579 (231)1,598 (95)
  • a Added to CSE medium.

  • b All measurements were performed at least in triplicate. Values in parentheses indicate the standard deviations.