TABLE 2.

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

Carbon sourceaEnzyme activityb in U/mg of protein (SD) for strain:
168c (wild type)GP270 (ΔxylR)GP297 (ΔxylR Δcrh)GP284 (ΔxylR ptsH1)GP287 (ΔxylR Δcrh ptsH1)GP289 (ΔxylR ΔhprK)GP853 (ΔxylR ΔccpA)
None (CSE)945 (281)1,585 (560)2,748 (540)2,590 (304)2,397 (214)2,287 (218)2,142 (384)
Ribose497 (138)939 (164)1,360 (169)971 (263)1,346 (151)NG1,780 (454)
Arabinose414 (136)600 (153)876 (35)713 (100)1,498 (323)1,257 (70)1,437 (228)
Maltose437 (127)489 (32)488 (105)710 (81)2,226 (206)2,023 (408)2,078 (632)
Gluconate116 (11)201 (31)378 (64)244 (46)1,220 (179)1,163 (170)1,628 (554)
Sucrose126 (20)205 (12)203 (13)309 (88)2,770 (136)2,271 (292)2,858 (123)
Salicin54 (6)175 (19)167 (4)202 (37)2,850 (180)2,743 (667)2,049 (83)
Sorbitol114 (20)121 (29)130 (52)113 (19)732 (66)748 (61)734 (51)
Glycerol82 (15)96 (20)87 (6)135 (17)2,164 (110)1,273 (160)1,138 (127)
Mannitol72 (13)79 (21)78 (18)606 (190)2,080 (395)1,689 (269)1,265 (454)
Fructose60 (9)63 (5)63 (7)231 (75)2,045 (206)1,638 (32)1,889 (147)
Glucose7 (3)44 (10)60 (21)173 (56)2,077 (500)1,679 (421)1,570 (153)
  • a That is, added to the CSE medium.

  • b The values are the average of at least three independent experiments. NG, no growth.

  • c Xylose was added to induce xynPB expression.