Fig. 3
Expression analysis of eGFP and IeGFP regulated by the Pac promoter in Bt strain. a, b The expression of IeGFP (panel a) and eGFP (panel b) in Bt at different times (9, 12, 24, 36, 48, 60 and 72 h after inoculation) were analyzed respectively by western blot. “S” represents the supernatant of cell culture and “P” represents the resuspended cells by PBS buffer. Lane “M” is the molecular weight standards. c, d The fluorescent intensities of the harvested cells (panel c) or the supernatants of cell cultures (panel d) and their fold changes for BAc-IeGFP over BAc-eGFP strain at corresponding culture time. The slit widths of EX/EM were both 3 nm and the detections were conducted in low sensitivity for the resuspended cells and in high sensitivity for the supernatant. The fluorescent signals of B304 cells cannot be detected and the fluorescent intensity of the 72 h supernatant of BAc-IeGFP strain cell culture was beyond the limit (1000 A.U.). The error bars indicate standard error of mean. The significant differences of the fluorescent intensities between BAc-IeGFP and BAc-eGFP strains at corresponding time were indicated by single asterisk (p < 0.05) or double asterisks (p < 0.01). e Comparison of the collected cells before (up) and after excitement (down) when they were incubated for 24 h and 48 h. The cells were excited by blue light using Luyor 3415RG hand held lamp