Table 5.
Effect of pH (scale 3 to 11) on the Lactobacillus helveticus (BLh) bacteriocin activity against Gram-positive bacteria.
| Gram-positive bacterial strains | Zone of inhibition (mm) vs. pH variations | Pearson's correlation b/w pH variations and activity (P value = 0.05 (two-tailed)) | R squared (r2) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ||||
| BLh bacteriocin | E. faecium | 10.83 | 15.80 | 4.0 | 3.5 | 0.9 | 0.08 | 0.24 | 0.04 | 0.30 | P = 0.00799 (significant) | 0.6589 |
| B. subtilis | 10.0 | 15.13 | 10 | 5.0 | 1.2 | 0.07 | 0.04 | 0.04 | 0.10 | P = 0.002118 (significant) | 0.7621 | |
| S. pyogenes | 9.06 | 13.83 | 12.0 | 10.0 | 1.5 | 0.32 | 0.06 | 0.02 | 0.03 | P = 0.002734 (significant) | 0.7451 | |
| S. aureus | 8.23 | 12.90 | 25.0 | 15.0 | 2.0 | 0.22 | 0.29 | 0.02 | 0.03 | P = 0.038482 (significant) | 0.4809 | |
| MRSA | 6.56 | 11.96 | 30.0 | 20.0 | 3.56 | 0.28 | 0.58 | 0.42 | 0.42 | P = 0.091685 (not significant) | 0.3535 | |