Table 2 Antibacterial activity of silver nanoparticles synthesized by using CP leaf and callus extract against various microorganisms. The data were statistically evaluated through one-way analysis of variance. The data represents mean ± standard deviation. Data for each column in the respective bacteria followed by the different letters (a to h) are significantly different according to Duncan’s multiple range test [29] at P < 0.05. These letters (a to h) usually compare the means of different concentrations and the treatments

Escherichia coli

40 μl

13.06 ± 0.40^a

19.50 ± 0.5^d

15.83 ± 0.76^b,c

20.16 ± 0.76^d,e

50 μl

13.83 ± 0.76^a

20.73 ± 0.87^d,e,f

15.90 ± 0.49^b,c

20.83 ± 0.85^e,f

60 μl

15.23 ± 0.68^b

21.66 ± 0.76^f

16.66 ± 0.57^c

23.00 ± 0.50^g

Positive control

Negative control

Pseudomonas sp.

40 μl

14.50 ± 0.50^a

19.16 ± 1.25^d

15.83 ± 0.76^b,c

20.50 ± 0.50^e

50 μl

15.66 ± 0.76^a,b,c

21.00 ± 1.00^e

15.06 ± 0.60^a,b

21.52 ± 0.50^e,f

60 μl

15.73 ± 0.25^a,b,c

21.67 ± 0.25^e,f

16.83 ± 0.76^c

22.33 ± 0.57^g

Positive control

Negative control

Staphylococcus aureus

40 μl

14.66 ± 0.57^b,c

19.00 ± 0.50^d

14.00 ± 1.00^b

20.50 ± 0.50^e

50 μl

15.83 ± 0.76^c

21.16 ± 1.04^e,f

16.00 ± 1.00^c

21.66 ± 1.52^e,f

60 μl

0.00 ± 0.00^a

22.16 ± 1.52^f

0.00 ± 0.00^a

21.50 ± 0.50^e,f

Positive control

Negative control

Bacillus subtilis

40 μl

13.00 ± 1.00^a

18.33 ± 0.57^c,d

13.00 ± 1.00^a

20.73 ± 0.75^e

50 μl

14.16 ± 0.76^ab

19.16 ± 0.57^d

14.33 ± 0.76^a,b

21.33 ± 1.25^e

60 μl

15.56 ± 1.10^b

21.33 ± 1.25^e

17.16 ± 0.76^c

24.00 ± 1.00^f

Positive control

Negative control