FIGURE 4.

Growth curve, siderophore production, and bacteriostasis of AS19 at different Fe³⁺ concentrations. (A) Effect of different concentrations of Fe³⁺ on AS19 siderophore production. AS19 was cultured in SA medium containing different concentrations of Fe³⁺ at 30°C and 200 rpm. (B) Effect of different concentrations of Fe³⁺ on AS19 growth. AS19 was inoculated into SA medium containing different concentrations of Fe³⁺ at 30°C and 200 rpm. (C) Effect of different concentrations of Fe³⁺ on AS19 bacteriostatic activity. AS19 was inoculated into SA medium containing different concentrations of Fe³⁺ at 30°C and 200 rpm for 48 h. One milliliters of bacterial solution were centrifuged at 12,000 rpm for 10 min. The CFS was used for the plate bacteriostasis test. (D) Effect of different concentrations of Fe³⁺ on AS19 growth at 48 h. (ns, no significant difference, *p < 0.05, ^**p < 0.01, ^***p < 0.001).