Table 6 Mean of diameter of inhibition zones obtained by purified melanin pigment against tested bacterial strains
Microbial strains | Mean of diameter of inhibition zone (mm) ± standard deviation | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Different concentrations of melanin pigment (µg/mL) | MIC (µg/mL) | MBC (µg/mL) | Antibiotic (Positive control) | DMSO (1%) (Negative control) | ||||||
Streptomycin (10 µg/mL) | Tetracycline (10 µg/mL) | |||||||||
10 | 20 | 30 | 40 | 50 | ||||||
Gram-positive bacteria | ||||||||||
Staphylococcus aureus (SA-04) | 0.0 ± 0.0 | 9.3 ± 0.47 | 13.0 ± 0.0 | 12.0 ± 0.0 | 19.5 ± 0.02 | 25 | 50 | 30.5 ± 0.05 | 15.0 ± 0.47 | 0.0 ± 0.0 |
Gram-negative bacteria | ||||||||||
Escherichia coli )EC-03( | 0.0 ± 0.0 | 0.0 ± 0.0 | 8.3 ± 0.47 | 9.6 ± 0.94 | 12.5 ± 0.05 | 25 | 100 | 25.0 ± 0.00 | 13.3 ± 0.47 | 0.0 ± 0.0 |
Klebsiella pneumonia )KP-01( | 0.0 ± 0.0 | 8.3 ± 0.47 | 11.0 ± 0.0 | 14.3 ± 0.47 | 16.0 ± 0.13 | 12.5 | 100 | 27.3 ± 0.47 | 15.0 ± 0.02 | 0.0 ± 0.0 |
Pseudomonas aeruginosa )PA-09( | 11.3 ± 0.0 | 14.6 ± 0.94 | 16.0 ± 0.0 | 21.0 ± 0.0 | 35.3 ± 0.47 | 6.25 | 25 | 27.3 ± 0.47 | 15.0 ± 0.00 | 0.0 ± 0.0 |