Figure 2

Western blot analysis and optimization of RecA induction. (a) Western blot analysis with an anti-RecA antibody indicated the expression of RecA in the presence of xylose. Remarkably, expression of RecA in the absence of xylose was strictly repressed. BEST310/ΔrecA, that was constructed by replacing the endogenous recA of BEST310 with tet of pCTP, was used as a negative control. (b) Schematic diagram of the cloning procedure. erm, erythromycin resistance gene; Em^S, erythromycin sensitive; Em^R, erythromycin resistant. (c) Numbers of erythromycin-resistant colonies under various induction times after addition of 1.0% xylose. Error bars, s.d. n = 3. (d) Numbers of erythromycin-resistant colonies under various xylose concentrations at 150 min induction. Error bars, s.d. n = 3. (e) Erythromycin-resistant recombinants were obtained only in the presence of xylose. The picture of xylose (+) is representative plate at a final xylose concentration of 1.0% at the induction time of 150 min. (f) All colonies formed on LB plates containing erythromycin were fluorescent due to their GFP gene.