Fig. 5

GFP expression using inducer-free plasmids based on Pgrac01 and Pgrac100. E. coli OmniMax and B. subtilis 1012 carrying expression plasmids with either the Pgrac01 promoter such as pHT10-gfp+ (inducible), pHT1650, pHT1651 or the Pgrac100 promoter such as pHT1168 (inducible), pHT1695, pHT1696 were generated. Cells were grown in LB medium to mid-log, and production of GFP was induced by addition of 1 mM IPTG. Aliquots were taken before and 4 h after addition of IPTG. Cells were lysed by lysozyme, and aliquots were measured for GFP activities and analyzed by SDS-PAGE. a Activities of gfp expression in E. coli to analyze for the repression ability of the inducer-free vector. b Activities of gfp expression in B. subtilis to measure the inducer-free production levels. c SDS-PAGE analysis of the gfp expression in B. subtilis; black dots indicate the positions of GFP