FIGURE 7.

Effect of exogenous Mn²⁺ ion on the growth and biofilm formation by P. putida MnB1. (A) Microbial growth was detected by measuring the absorbance at 600 nm. P. putida MnB1 was incubated with 0, 40, 200, 1000, and 5000 μM Mn²⁺, respectively. Biofilm formation by P. putida MnB1 was quantified by CV staining with absorbance at 590 nm. Cells were incubated with Mn²⁺ (0, 40, 200, 1000, and 5000 μM) for 6 and 12 h (n = 6) (B). Data were expressed as mean ± SEM. Significance, ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗ P < 0.001 vs. control group (0 μM MnCl₂).