TABLE 2.

Anaerobic growth in the presence of Fe(III) and Ag(I)

E. coli strains ECA613 (glmS-fetM) and ECA612 (glmS-fetMP) were anaerobically cultivated in the dark for 17 h at 37 °C in TMM with 100 μm Fe(III) and 0.2% glucose as a carbon source. In half of the samples, the growth medium was additionally supplemented with 1 μm Ag(I). Turbidity at 600 nm was determined, and averages of three independent experiments with S.D. values are shown. Statistics were done with Student's t test, 4 degrees of freedom. For comparison of ECA612/ECA613 without silver, F(t) = 41.6 (p > 0.999) and with silver F(t) = 5.6 (p > 0.995). For ECA613 with or without silver, F(t) = 6.1 (p > 0.995), and for ECA612 with or without silver, F(t) = 18.6 (p > 0.999).

Bacterial strains	Turbidity at 600 nm
	0 μm Ag(I)	1 μm Ag(I)
ECA613 (glmS-fetM)	0.647 ± 0.005	0.670 ± 0.008
ECA612 (glmS-fetMP)	0.873 ± 0.005	0.713 ± 0.012