Table 3.
Effects of different pH values on the biofilm formation of ATCC 14018.
| pH | OD measurement at 12 h (OD595nm) | OD measurement at 24 h (OD595nm) | OD measurement at 36 h (OD595nm) | OD measurement at 48 h (OD595nm) | OD measurement at 60 h (OD595nm) | OD measurement at 72 h (OD595nm) |
|---|---|---|---|---|---|---|
| Blank control | 0.23 ± 0.04 | 0.34 ± 0.02 | 0.38 ± 0.08 | 0.40 ± 0.06 | 0.43 ± 0.06 | 0.26 ± 0.05 |
| 3.5 | 0.46 ± 0.13 (W) | 0.49 ± 0.12 (W) | 0.52 ± 0.07 (N) | 0.47 ± 0.04 (N)a | 0.54 ± 0.06 (N) | 0.48 ± 0.12 (W) |
| 4 | 0.57 ± 0.12 (W) | 0.61 ± 0.05 (W) | 0.71 ± 0.11 (W) | 0.67 ± 0.13 (W)b | 0.72 ± 0.08 (W) | 0.69 ± 0.10 (W) |
| 4.5 | 1.18 ± 0.05 (M) | 1.82 ± 0.28 (S) | 2.03 ± 0.29 (S) | 2.28 ± 0.25 (S)c | 2.42 ± 0.28 (S) | 2.26 ± 0.55 (S) |
| 5 | 2.41 ± 0.28 (S) | 2.73 ± 0.19 (S) | 2.97 ± 0.51 (S) | 3.06 ± 0.24 (S)d | 3.34 ± 0.18 (S) | 3.09 ± 0.18 (S) |
| 5.5 | 2.69 ± 0.26 (S) | 2.98 ± 0.26 (S) | 3.29 ± 0.28 (S) | 3.10 ± 0.25 (S)e | 3.16 ± 0.21 (S) | 3.48 ± 0.18 (S) |
| 6 | 2.19 ± 0.21 (S) | 2.50 ± 0.75 (S) | 2.53 ± 0.53 (S) | 2.98 ± 0.10 (S)f | 3.07 ± 0.14 (S) | 3.08 ± 0.42 (S) |
| 6.5 | 1.07 ± 0.13 (M) | 1.40 ± 0.08 (M) | 1.93 ± 0.11 (M) | 2.36 ± 0.26 (S)g | 2.44 ± 0.20 (S) | 2.13 ± 0.23 (S) |
| 7 | 0.77 ± 0.13 (M) | 0.69 ± 0.10 (W) | 0.63 ± 0.12 (W) | 0.71 ± 0.12 (W)h | 0.74 ± 0.09 (W) | 0.55 ± 0.09 (W) |
| 7.5 | 0.48 ± 0.08 (W) | 0.31 ± 0.05 (N) | 0.39 ± 0.07 (N) | 0.31 ± 0.04 (N)i | 0.41 ± 0.06 (N) | 0.29 ± 0.01 (N) |
N, no biofilm formation; W, weak biofilm formation; M, moderate biofilm formation; S, strong biofilm formation. The results indicated that there were significant differences in biofilm formation at different pH values (p = 0.000). Intragroup comparison: Time was a significant factor for biofilm formation, and interaction was significant for biofilm formation (p = 0.000). Pab = 0.203; Pbc = 0.000; Pcd = 0.000; Pde = 0.115; Pef = 0.049; Pfg = 0.000; Pgh = 0.000; Phi = 0.001.