Evaluation of Antimicrobial Potential and Comparison of HPLC Composition, Secondary Metabolites Count, and Antioxidant Activity of Mentha rotundifolia and Mentha pulegium Extracts
Table 3
Antibacterial and antifungal activities of Mentha methanolic extracts against nine bacteria evaluated by disc diffusion and determination of MIC and MBC tests.
Strainsa
Inhibition zone diameters (mm)b
MIC (µg/ml)
MBC (µg/ml)
MR
MP
Antibiotics
MR
MP
MR
MP
Gram-negative bacteria
E. coli ATCC 8739
17 ± 0.5
16 ± 0.5
24
12.5
25
12.5
25
S. typhimurium NCTC 6017
15 ± 1
14 ± 0.5
23
12.5
25
25
50
S. arizona ATCC25922
15 ± 0.7
14 ± 0.4
23
12.5
25
25
50
P. aeruginosa ATCC 27853
17 ± 0.8
16 ± 0.3
21
12.5
25
12.5
25
Klebsiella pneumoniae
15 ± 0.5
14 ± 0.4
20
6.25
12.5
12.5
25
Gram-positive bacteria
L. monocytogenes ATCC 7644
13 ± 0.5
12 ± 0.5
18
12.5
25
25
50
B. cereus ATCC1247
12 ± 0.5
11 ± 0.6
21
12.5
25
25
50
E. faecalis
14 ± 0.6
13 ± 0.3
19
12.5
25
12.5
25
S. aureus
15 ± 0.4
14 ± 0.2
20
12.5
25
25
50
Fungus species
Aspergillus flavus
14 ± 0.4
13 ± 0.4
11
12.5
12.5
25
25
Aspergillus niger
16 ± 0.5
15 ± 0.3
11
12.5
12.5
25
25
Candida albicans
11 ± 0.6
11 ± 0.4
17
12.5
12.5
25
25
aThe final bacterial density was around 105 cfu/mL. bInhibition zone diameters (mm) produced around the wells were determined by adding 15 µL of methanol extracts. MIC: minimum inhibitory concentration (µg/ml); MBC: minimum bactericidal concentration (µg/ml). Values are means of three measurements; ±: standard deviation.
