Figure 2
From: Rapid in situ assessment of Cu-ion mediated effects and antibacterial efficacy of copper surfaces
Induction of bioluminescence in E. coli (pSLcueR/pDNPcopAlux) Cu biosensor in different test media. (a) Bioluminescence of the Cu biosensor on C11000 copper surfaces in Heavy Metal MOPS Medium (HMM) with 0.01 and 0.5% casein acid hydrolysate (HMM 0.5% AA and 0.01% AA, respectively), 1:500 diluted Nutrient Broth (NB) medium, Luria Bertani (LB) medium and Tryptone Soy Broth (TSB) medium. (b) Bacterial counts after 60 min exposure in the specified media on control or C11000 surface. Significant differences in viable counts from control value based on two-way analysis of variance (ANOVA) and Bonferroni’s multiple comparisons test are marked p < 0.1(.); p < 0.05(*); p < 0.01(**); p < 0.001(***); p < 0.0001(****); (c) bioluminescence of the Cu biosensor in different media in CuSO4 standard solutions (0.01–1000 mg/L Cu2+) after 60 min exposure. Solid red line indicates background, i.e., non-induced bioluminescence of E. coli (pSLcueR/pDNPcopAlux) and dotted red line indicates the limit for significantly increase bioluminescence. Arrows indicate concentrations of Cu ions that according to TR-XRF were released from C11000 surfaces within 60 min in each medium. (d) time-dependent induction of bioluminescence in E. coli (pSLcueR/pDNPcopAlux) copper sensor in the presence of Cu concentrations indicated with arrows on (c). Mean and standard deviation of three replicates are shown.
