## 3 Results and Discussion
### Antibacterial Activity of Synthesized AgNPs from Various Leaf and Stem Extracts
Whereas, the crude stem methanolic extracts had the highest inhibition against _S. aureus_ and _P. aeruginosa_ only. According to the HRTEM analysis, AgNPs synthesized from the various extracts ranged from 34.32-16.57 nm. Numerous studies have reported that AgNPs of smaller dimensions (<30 nm) have a greater ability to penetrate into bacteria ([PERSON], 2018; [PERSON], 2018). This suggests that smaller particles may engage with the contact surface of bacteria more frequently than larger ones, therefore improving their antibacterial activity ([PERSON], 2018; [PERSON], 2018). Additionally, the morphology and physicochemical characteristics of NPs have been recognized to exert an effect on their antimicrobial activities ([PERSON], 2018; [PERSON], 2018). [PERSON] et al. (2018) have found smaller size AgNPs to display greater surface area then the larger particles, resulting in improved antibacterial activity. This was further validated by [PERSON] et al. (2018), who have suggested that small-sized particles exhibit strong antibacterial activity, due to their enhanced capacity to penetrate bacterial cells. [PERSON] et al. (2018) have proposed that the bactericidal activity of AgNPs is due to the attachment of these particles to the cell wall. Ag\({}^{+}\) ions released from NPs promote antibacterial activity. Additionally, these positively charged ions react with the phosphorus  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Strain**} & \multirow{2}{*}{ \begin{tabular}{c} **Concentration** \\ **(mg/mL)** \\ \end{tabular}  } & \multicolumn{8}{c}{**Treatments/Synthesized AgNPs**} & \multicolumn{8}{c}{**Positive Control**} \\  & & \multicolumn{2}{c}{**(mg/mL)**} & \multicolumn{2}{c}{**Lesef**} & \multicolumn{2}{c}{**Fresh Leaves**} & \multicolumn{2}{c}{**Fowder**} & \multicolumn{2}{c}{**Stem**} & \multicolumn{2}{c}{**Fresh Stem**} & \multicolumn{2}{c}{**Power**} \\  & & **Methanol** & & **Leaves** & **Methanol** & & **Stem** & **Stem** & **L** & **S** \\ \hline BS & 3.125 & R & R & R & R & R & R & & \\  & 6.25 & R & R & R & R &  
and sulphur found in biomolecules such as DNA and RNA in the bacterial cells, thereby causing their disruption [113; 114]. According to various reports in the literature, the antibacterial potential of AgNPs is observed in their ability to denature the outer membrane of bacteria [115]; cause gaps/pits in the membrane, resulting in their destruction [116; 117]; and bring about an interaction between the AgNPs and sulfhydryl/disulphide groups of enzymes, hindering their metabolic processes and leading to cell death [118]. The potency of synthesized AgNPs from the leaves of _B. cristata_[75] and _B. gibsoni_[81] have showed antibacterial activity against _S. aureus_ and _E. coli_. AgNPs are known to affect various biological processes within microorganisms, as they modify the structure and function of the cell membrane, rendering them permeable [119]. AgNPs were reported to accumulate on the membrane of _E. coli_ cells, creating a gap in the integrity of the bilayer and increasing its permeability, resulting in bacterial cell death [75; 120]. For _P. aeruginosa_, AgNPs from the leaf methanolic extract displayed the highest inhibitory activity (21.67 \(\pm\) 2.87 mm), while the lowest was observed in the powdered AgNPs (15.00 \(\pm\) 4.00 mm). Additionally, no observed activity was observed at 3.125 mg/mL in the powdered leaf and stem methanolic AgNPs against _P. aeruginosa_ (Table 5). [PERSON] et al. [61] have evaluated the antibacterial activity of AgNPs synthesized from _B. longiflora_ aqueous leaf extracts. According to these authors, strong antibacterial activity at 100 mg/mL was observed against _S. aureus_ (14.5 \(\pm\) 0.08 mm) and _P. aeruginosa_ (18 \(\pm\) 0.14 mm). Therefore, the biosynthesized AgNPs from the leaves and stem extracts of _B. albostellata_, exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria.