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Table 2 β-Galactosidase activity and transcript levels

From: Quantitative transcript analysis of the inducible expression system pSIP: comparison of the overexpression of Lactobacillus spp. β-galactosidases in Lactobacillus plantarum

Time (h) Time after induction (h) pEH9R PCN ratio pEH9R/pEH9A pEH9A
   Activitya lacLM expression level sppKR expression level   Activitya lacLM expression level sppKR expression level
6 b 0 1 1.00 ± 0.07 1.00 ± 0.16 1.39 ± 0.25 1 1.00 ± 0.13 1.00 ± 0.21
8 2 56.1 59.9 ± 15.6 1.88 ± 0.11 0.81 ± 0.07 2.42 17.8 ± 4.3 2.49 ± 0.04
12 6 135 55.4 ± 13.5 1.67 ± 0.39 0.79 ± 0.01 4.48 11.9 ± 1.9 2.00 ± 0.20
24 18 144 16.4 ± 2.6 - 1.34 ± 0.06 3.56 0.46 ± 0.12 -
  1. Activity levels and transcript levels of lacLM and sppKR in strains harboring pEH9R or pEH9A are related to the respective values at the induction point (6 h into the cultivation)
  2. The plasmid copy number (PCN) ratio is the value for the pEH9R-harboring strain divided by the value for the pEH9A-harboring strain
  3. a Specific activity (U/mg protein)
  4. b Just before induction