TABLE 3.

Comparison of catabolite repression by different substrates, the relative amounts of the different HPr forms, and the intracellular FBP concentrationa

Carbon sourcebFold repressioncRelative amt (%)d of HPr formConcn of fructose-1,6-bis-P (mM)Growth rate (μ) h−1
HPr-Ser∼PHPr-His∼PHPrHPr-Ser∼P-His∼P
None (CSE)13 (3)40 (14)42 (19)5 (2)1.8 (0.5)0.29 (0.03)
Ribose227 (1)37 (6)25 (9)11 (4)6.5 (0.1)0.76 (0.07)
Arabinose321 (1)29 (9)13 (10)37 (1)8.1 (0.5)0.98 (0.06)
Maltose613 (1)47 (4)25 (6)15 (1)10.7 (0.8)0.85 (0.01)
Gluconate732 (10)29 (4)9 (2)30 (9)12.3 (3.6)0.94 (0.09)
Sucrose1466033111.5 (1.9)0.85 (0.02)
Salicin1750 (9)050 (9)09.4 (2.1)0.91 (0.04)
Sorbitol2166 (6)032 (7)2 (1)4.4 (2.1)0.83 (0.03)
Glycerol3246 (3)12 (6)042 (4)4.3 (1.6)0.94 (0.11)
Mannitol3570 (6)030 (6)04.4 (0.6)0.86 (0.03)
Fructose4460 (2)040 (3)013.3 (3.0)0.94 (0.07)
Glucose4658 (6)035 (10)7 (7)14.1 (1.3)0.95 (0.07)
  • a Standard deviations are given in parentheses.

  • b That is, added to the CSE medium. For growth rate determinations, CE medium plus a single carbon source was used.

  • c In the ΔxylR Δcrh mutant.

  • d Mean values of at least two independent experiments are presented except for sucrose, for which only one experiment was performed.