Figure 3
From: “NiCo Buster”: engineering E. coli for fast and efficient capture of cobalt and nickel
Functionality of the NiCoT transporter in the engineered strain. A) Uptake of nickel by the engineered transporter. The strains S59 (MG1655 nikA) and S63 (S59/pIG50) were cultured in LB medium to an OD600 of 0.6, at which time 150 nM 63NiCl2 was added. The cells were recovered after 0, 2.5, 5, 10, 15, 20 and 30 minutes of contact by filtration using a nitrocellulose filter. The captured nickel was estimated by measuring the radioactivity of the filter. Data represent the mean of 2 replicates, and error bars represent standard deviations. B) Cell viability tests. The sensitivities of wild type (S29), rcnA mutant (S48) and engineered (S61) strains towards nickel and cobalt were compared. Five microliters of cells at the indicated concentrations were spotted onto M63G (supplemented or not supplemented with metal) and incubated at 37°C for 48 h. Metal concentrations ranging from 1 μM to 50 μM were tested. Only one concentration (indicated below the image) is shown, corresponding to the MIC of strain S61. In the presence of 20 μM Ni(II), the engineered strain exhibited no growth; in contrast, the growth of the parental strain was not affected, and the growth of the rcnA chassis was slightly decreased.