Fig 2.

E. coli survival and lipid peroxidation on copper-zinc alloy surfaces containing different copper concentrations. E. coli strain ATCC 23724 was grown in LB medium to mid-log phase (OD₆₀₀, 0.3), harvested by centrifugation from 100 ml of culture, and resuspended in 0.85% NaCl to a final volume of 500 μl. Samples (100 μl) of concentrated cells were spread over the surface of metal coupons of 304 stainless steel (S30400), 99.90% copper (C11000), and copper-zinc alloys C24000, C26000, and C28000, containing 80%, 70%, 60% copper, respectively (with the remainder zinc). (A) Following the indicated time of exposure, the cells were washed from the coupon surface with 100 μl of 0.85% NaCl, and samples were taken to determine survival titers, as described for Fig. 1A. (B) Results of the TBARS assay on cells exposed and recovered from the different alloys at the indicated times, as described for panel A. The results represent at least two independent trials. The legend applies to both panels A and B.