Table 2 Mean inhibition zone results of A. occidentale leaf extract-mediated biosynthesized ZnO nanoaggregates from the two precursors against selected microbes [S. aureus, E. aquaticum (Gram positive) and E. coli, K. pneumonia, A. baumanni (Gram negative)]

Concentration (ppm)

ZnO NPs type

E. coli (Gram −ve)

S. aureus (Gram +ve)

A. baumannii (Gram −ve)

E. aquaticum (Gram +ve)

K. pneumoniae (Gram −ve)

Control

3.06 ± 0.01 mm

3.05 ± 0.06 mm

3.07 ± 0.02 mm

3.06 ± 0.01 mm

3.08 ± 0.03 mm

25

ZnAc

1.60 ± 0.04 mm

1.49 ± 0.03 mm

1.89 ± 0.08 mm

1.61 ± 0.11 mm

1.91 ± 0.10^a mm

ZnCl₂

1.12 ± 0.04 mm

1.06 ± 0.14 mm

1.27 ± 0.13 mm

1.25 ± 0.14 mm

1.30 ± 0.22^a mm

50

ZnAc

1.68 ± 0.03 mm

1.61 ± 0.11 mm

1.90 ± 0.02^a mm

1.62 ± 0.07 mm

2.04 ± 0.15^a mm

ZnCl₂

1.13 ± 0.34 mm

1.23 ± 1.13 mm

1.29 ± 0.18^a mm

1.17 ± 0.05 mm

1.29 ± 0.12^a mm

100

ZnAc

1.69 ± 0.04 mm

1.62 ± 0.11 mm

1.79 ± 0.09^a mm

1.82 ± 0.16 mm

1.88 ± 0.02^a mm

ZnCl₂

1.23 ± 0.07 mm

1.27 ± 0.17 mm

1.24 ± 0.16^a mm

1.33 ± 0.21 mm

1.37 ± 0.16^a mm

250

ZnAc

1.78 ± 0.06 mm

1.87 ± 0.10^a mm

1.76 ± 0.05 mm

1.71 ± 0.31 mm

1.65 ± 0.17 mm

ZnCl₂

1.29 ± 0.19 mm

1.33 ± 0.15^a mm

1.30 ± 0.17 mm

1.29 ± 0.19 mm

1.30 ± 0.12 mm

500

ZnAc

1.71 ± 0.16 mm

1.64 ± 0.11 mm

1.82 ± 0.09 mm

1.79 ± 0.07 mm

1.86 ± 0.12^a mm

ZnCl₂

1.37 ± 0.13 mm

1.35 ± 0.14 mm

1.35 ± 0.10 mm

1.37 ± 0.15 mm

1.38 ± 0.06^a mm

1000

ZnAc

1.94 ± 0.04 mm

1.90 ± 0.13 mm

2.01 ± 0.23^ab mm

2.00 ± 0.10 mm

2.08 ± 0.03^b mm

ZnCl₂

1.39 ± 0.18^bmm

1.36 ± 0.08 mm

1.39 ± 0.12^b mm

1.38 ± 0.09 mm

1.40 ± 0.10^b mm