Table 2.
The antimicrobial effects of GTEs, concentrations and inhibition zones (n = 3).
| Studied Microorganisms | Conc. (%) | OGTE | AGTE | BMGTE | WGTE | BkBGTE | BBGTE | BCGTE |
|---|---|---|---|---|---|---|---|---|
| Gram-positive bacteria | ||||||||
| B. cereus | 100 | 12.34 ± 0.46 d,e | 10.17 ± 0.92 a,b,c,d | 9.96 ± 0.55 a | 13.19 ± 1.17 d,e | nd | 10.45 ± 0.55 c,d | nd |
| 90 | 11.59 ± 0.34 c,d,e | 9.71 ± 0.30 a,b | 9.67 ± 0.69 a | 11.79 ± 0.83 b,c,d | nd | 10.70 ± 0.85 c,d,e,f | nd | |
| 80 | 12.54 ± 1.65 e | 9.40 ± 0.28 a | 10.18 ± 0.73 a | 11.74 ± 0.59 b,c,d | nd | 10.56 ± 0.65 c,d,e | nd | |
| 70 | 10.59 ± 0.46 b,c | 9.53 ± 0.27 a,b | 9.70 ± 0.54 a | 10.95 ± 0.82 a,b | nd | 9.91 ± 0.57 a,b,c | nd | |
| 60 | 10.73 ± 0.30 b,c | nd | nd | 11.29 ± 0.49 a,b,c | nd | nd | nd | |
| 50 | 9.68 ± 0.60 a,b | nd | nd | 10.22 ± 0.52 a,b | nd | nd | nd | |
| 40 | nd | nd | nd | 10.18 ± 0.33 a | nd | nd | nd | |
| 30 | nd | nd | nd | nd | nd | nd | nd | |
| S. aureus | 100 | 10.52 ± 0.18 b,c | nd | nd | nd | 12.2 ± 0.51 c,d | nd | nd |
| 90 | 11.32 ± 0.31 c,d | nd | nd | nd | 10.47 ± 0.40 a | nd | nd | |
| 80 | 10.96 ± 0.43 c | nd | nd | nd | 10.79 ± 1.06 a,b,c | nd | nd | |
| 70 | 10.54 ± 0.55 b,c | nd | nd | nd | 13.95 ± 0.63 e,f | nd | nd | |
| 60 | 10.55 ± 0.27 b,c | nd | nd | nd | 13.29 ± 0.65 d,e | nd | nd | |
| 50 | 9.24 ± 0.15 a | nd | nd | nd | 13.22 ± 0.58 d,e | nd | nd | |
| 40 | nd | nd | nd | nd | 9.81 ± 0.56 a | nd | nd | |
| 30 | nd | nd | nd | nd | nd | nd | nd | |
| E. faecalis | 100 | 10.95 ± 0.60 c | 13.86 ± 0.46 m,n | nd | 10.99 ± 0.91 a,b,c | nd | 10.91 ± 0.46 d,e,f | nd |
| 90 | nd | 14.17 ± 0.55 n | nd | 10.53 ± 0.97 a,b | nd | 10.49 ± 0.63 c,d | nd | |
| 80 | nd | 13.30 ± 0.29 m,n | nd | 10.09 ± 0.59 a | nd | 9.97 ± 0.18 a,b,c,d | nd | |
| 70 | nd | 13.03 ± 0.42 k,l,m | nd | nd | nd | 10.00 ± 0.20 a,b,c,d | nd | |
| 60 | nd | 12.88 ± 0.28 k,l | nd | nd | nd | 9.84 ± 0.26 a,b,c | nd | |
| 50 | nd | 12.75 ± 0.55 j,k,l | nd | nd | nd | 10.14 ± 0.42 b,c,d | nd | |
| 40 | nd | 11.88 ± 0.56 h,i,j | nd | nd | nd | nd | nd | |
| 30 | nd | 10.11 ± 0.51 a,b,c,d | nd | nd | nd | nd | nd | |
| 20 | nd | nd | nd | nd | nd | nd | nd | |
| L. monocytogenes | 100 | 9.71 ± 0.62 a,b | nd | nd | 21.98 ± 1.13 i | 19.20 ± 0.87 i | nd | 10.81 ± 0.74 b |
| 90 | nd | nd | nd | 17.16 ± 0.90 g,h | 18.71 ± 0.60 h,i | nd | 10.77 ± 0.41 b | |
| 80 | nd | nd | nd | 18.08 ± 0.41 h | 18.59 ± 0.41 h,i | nd | nd | |
| 70 | nd | nd | nd | 15.53 ± 0.83 f,g | 17.84 ± 0.71 g,h,i | nd | nd | |
| 60 | nd | nd | nd | 16.73 ± 0.69 g,h | 17.37 ± 2.31 g,h | nd | nd | |
| 50 | nd | nd | nd | 14.13 ± 0.47 e,f | 17.33 ± 0.46 g,h | nd | nd | |
| 40 | nd | nd | nd | 15.07 ± 1.46 f | 16.93 ± 0.68 g | nd | nd | |
| 30 | nd | nd | nd | 13.33 ± 0.49 d,e | 15.4 ± 0.73 f | nd | nd | |
| 20 | nd | nd | nd | 12.61 ± 0.96 c,d,e | 13.4 ± 0.53 d,e | nd | nd | |
| 10 | nd | nd | nd | nd | nd | nd | nd | |
| Gram-negative bacteria | ||||||||
| P. vulgaris | 100 | 11.09 ± 0.33 c | 11.14 ± 0.99 e,f,g,h | 10.40 ± 0.37 a,b | 10.33 ± 0.34 a,b | 12.77 ± 0.64 d,e | 12.76 ± 0.80 h,i | nd |
| 90 | 11.05 ± 0.44 c | 12.12 ± 0.84 i,j,k | 10.53 ± 0.58 a,b | nd | 11.18 ± 0.45 a,b,c | 13.55 ± 0.75 i,j | nd | |
| 80 | 10.94 ± 0.52 c | 11.57 ± 0.73 f,g,h,i | 11.52 ± 1.31 b | nd | 10.99 ± 0.30 a,b,c | 15.04 ± 1.03 k | nd | |
| 70 | 11.40 ± 0.42 c,d | 10.69 ± 0.64 c,d,e,f | nd | nd | nd | 14.24 ± 0.86 j,k | nd | |
| 60 | 9.02 ± 0.37 a | 10.00 ± 0.71 a,b,c,d | nd | nd | nd | 11.91 ± 0.48 g,h | nd | |
| 50 | 8.78 ± 0.22 a | 10.44 ± 0.33 b,c,d,e | nd | nd | nd | 10.59 ± 0.38 c,d,e | nd | |
| 40 | nd | 10.91 ± 0.76 d,e,f,g | nd | nd | nd | 11.64 ± 0.57 f,g | nd | |
| 30 | nd | nd | nd | nd | nd | 10.15 ± 0.45 b,c,d | nd | |
| 20 | nd | nd | nd | nd | nd | nd | nd | |
| P. aeruginosa | 100 | nd | nd | nd | nd | nd | nd | nd |
| E. coli | 100 | nd | nd | nd | nd | nd | nd | nd |
| S. enterica | 100 | nd | nd | nd | nd | nd | nd | nd |
| Yeast | ||||||||
| S. cerevisiae | 100 | nd | 11.76 ± 0.66 g,h,i | nd | nd | 10.39 ± 0.43 a | 10.84 ± 0.37 c,d,e,f | 9.63 ± 0.35 a |
| 90 | nd | 11.84 ± 0.14 g,h,i,j | nd | nd | 11.97 ± 0.64 b,c,d | 11.68 ± 0.9 f,g | 10.61 ± 0.96 a,b | |
| 80 | nd | 10.20 ± 0.16 a,b,c,d,e | nd | nd | 10.43 ± 0.42 a | 11.52 ± 0.56 e,f,g | 10.90 ± 0.20 b | |
| 70 | nd | 9.95 ± 0.28 a,b,c | nd | nd | 10.56 ± 0.55 a,b | 9.90 ± 0.48 a,b,c | 9.78 ± 0.38 a | |
| 60 | nd | 9.43 ± 0.13 a | nd | nd | nd | nd | nd | |
| 50 | nd | nd | nd | nd | nd | nd | nd | |
| Moulds | ||||||||
| A. niger | 100 | nd | nd | nd | nd | nd | nd | nd |
| A. flavus | 100 | nd | nd | nd | nd | 10.4 ± 0.27 | nd | nd |
| 90 | nd | nd | nd | nd | 10.13 ± 0.25 | nd | nd | |
| 80 | nd | nd | nd | nd | 9.76 ± 0.54 | nd | nd | |
| 70 | nd | nd | nd | nd | 9.42 ± 0.25 | nd | nd | |
| 60 | nd | nd | nd | nd | nd | nd | nd | |
| A. ochraceus | 100 | nd | nd | nd | nd | 10.47 ± 0.7 | nd | nd |
| 90 | nd | nd | nd | nd | 10.07 ± 0.26 | nd | nd | |
| 80 | nd | nd | nd | nd | 9.96 ± 0.22 | nd | nd | |
| 70 | nd | nd | nd | nd | 9.56 ± 0.19 | nd | nd | |
| 60 | nd | nd | nd | nd | nd | nd | nd | |
| P. citrinum | 100 | nd | nd | nd | nd | 14.02 ± 0.64 | 9.34 ± 0.25 | nd |
| 90 | nd | nd | nd | nd | 13.22 ± 0.32 | 9.09 ± 0.31 | nd | |
| 80 | nd | nd | nd | nd | 12.81 ± 0.36 | 8.83 ± 0.35 | nd | |
| 70 | nd | nd | nd | nd | 11.91 ± 0.24 | 9.00 ± 0.18 | nd | |
| 60 | nd | nd | nd | nd | nd | nd | nd | |
| P. expansum | 100 | nd | nd | nd | nd | 9.09 ± 0.07 | nd | nd |
| 90 | nd | nd | nd | nd | 8.87 ± 0.19 | nd | nd | |
| 80 | nd | nd | nd | nd | 8.90 ± 0.22 | nd | nd | |
| 70 | nd | nd | nd | nd | 8.83 ± 0.14 | nd | nd | |
| 60 | nd | nd | nd | nd | nd | nd | nd | |
nd—not detectable. Results are expressed as the mean in mm ± SD. Inhibition zones, including the diameter of the hole (8 mm). Values with different letters (a–n) within a column are statistically different at p < 0.05, according to Tukey’s test.