Figure 6
Effect of fumarate reductase on selenite reduction in E. cloacae Z0206. (A) Effect of fumarate on the growth of E. cloacae Z0206. The bacteria were cultured with the addition of 10 mM, 20 mM, or 50 mM fumarate or without the presence of fumarate; the OD600 values were measured at the indicated time point after 3-fold dilution. (B) Effect of fumarate on the selenite reduction rate. The bacteria were cultured in the presence of 5 mM selenite with or without 20 mM fumarate treatment. Samples were collected at different time points and centrifuged at 4 °C at 10,000 × g for 10 min, and the supernatant was used to determine the selenite residue. The selenite residue was converted to a percentage of the initial selenite concentration. (C) Effect of fumarate reductase mutation on the growth of E. cloacae Z0206. (D) Effect of fumarate reductase mutation on the selenite reduction rate in E. cloacae Z0206. *P < 0.05, **P < 0.01 (n = 3), compared with the selenite residue of the control group or the wild-type group at the same time.
