We measured the induction of D-glucose/β-lactose/IPTG with the lactose promoter (R0010) in E. coli Nissle 1917 (EcN) in M9 medium using a fully automated ELISA.
Figure 1. schematic diagram of BBa_K4183005
We overnight cultured engineered bacteria containing plasmid BBa_K4183005 in 5 ml LB medium and subsequently inoculated them into medium containing M9 (with different carbon sources or IPTG) and incubated at 37°C in a fully automated ELISA, with plate shaking every 15 min and data measured every 30 min.
The results showed that EcN growth was consistent under different carbon sources (glucose/lactose) (Figure 2A), and all of them could activate the expression of R0010. The expression intensity of R0010 was higher when the carbon source was D-glucose (Figure 2B). However, when the carbon source was β-lactose, the expression intensity of R0010 was low with or without the addition of IPTG (Figure 2B).
Figure 2. Growth of EcN and expression of R0010 in M9 medium under different conditions.
(A) OD600 of each well was measured at 0.5 h intervals in M9 medium under different conditions.
(B) Fluorescence intensity of each well was measured at 0.5 h intervals in M9 medium under different conditions with excitation light at 485 nm and emission light at 510 nm, N=3.