## 4 Discussion
During the fabrication of the LP-ZnO-NP samples, the compounds of the _Lavandula pubescens_ shoot methanol extract were used as a reducing agent to develop ZnO NPs, and their formation, as well as structural features, were evaluated by UV-vis, XRD, and TEM. We next investigated the antimicrobial capabilities of the LP-ZnO NPs against _P. aeruginosa_ (Gram-negative bacterium) and _S. aureus_ (Gram-positive bacterium), A. niger, A. terrus, and Staphylococcus aureus. The presence of the ZnO main XRD band and FT-IR band in the manufactured nanoparticles, as well as the functionalization of the ZnO by the LPME compounds as reducing and capping agents, ascertained that the functionalization led to nanosized agglomerated LP-ZnO NP rods (Figure S4, Figure 1). Additionally, the production of the nanosized LP-ZnO NPs was indicated by the broadening of the (101) diffraction peaks [53]. Regarding our FT-IR results (Figure S5), we observed changes in the intensity or shifts in the positions of the IR bands of the LPME after the fabrication of the ZnO nanoparticles, which suggested that the bioactive compounds bonded to the ZnO surface. It has been reported that the bioactive compounds present in plant extracts, such as polyphenols (flavonoids), have hydroxyl and ketonic groups that bind to bulk metal oxide to reduce it to a nanosize [65]. In more detail, LPME carboxylic acids and phenolic compounds probably interact with ZnO, as evidenced by the appearance of C-O functional groups in nanoparticles [21; 54]. These findings confirmed the functionalization of ZnO nanoparticles as well. The high thermal stability of ZnO nanoparticles (Figure S6), with the stability higher in the 50 mg LP-ZnO NPs than 100 mg LP-ZnO NPs, conforms to the finding reported earlier [4]. This suggeststhat these nanoparticles can be used as antimicrobial additives in the food industry. The biofabrication of ZnO nanoparticles from plants and their use as antimicrobial agents have been extensively investigated by many authors [25; 66]. ZnO NPs have been investigated as an alternative antibiotic to improve the antibacterial effect against pathogenic strains. They have unique physicochemical characteristics that might affect how bacteria react biologically and toxicologically. They primarily work against microbes by releasing metal ions, adsorbing particles, and producing reactive oxygen species [16]. Furthermore, we went through the physicochemical characteristics of the synthesized LP-ZnO NPs so that we could understand how effective they are against harmful microbes, and specifically the effect of the _L. pubescens_ shoot methanol extract on the growth of _Staphylococcus aureus_ (Gram-positive bacterium), _Pseudomonas aeruginosa_ (Gram-negative bacterium), _Aspergillus terreus_, and _Aspergillus niger_. To combat the multidrug resistance, scientists have looked at zinc oxide nanoparticles for use in developing next-generation nano-antibiotics against pathogenic bacteria [3; 67]. The agar well diffusion approach was used to detect the inhibitory zones (ZIs) of the tested microbes created by the fabricated LP-ZnO NPs, which indicated the antimicrobial potential of the LP-ZnO NPs. Next, using the broth microdilution method, the minimum inhibitory concentrations (MICs) and minimum bactericidal/fungicidal concentrations (MBCs/MFCs) of the LP-ZnO NPs were determined. We noticed that the growth behavior of the tested bacteria and fungi after the ZnO nanoparticle treatment varied depending on the type of microbe, the antimicrobial substance's qualities, and the type of solvent (Table 2 and Figure 2a-c). The biofabricated ZnO nanoparticles improved the antimicrobial performance of the ZnO alone, which resulted from the reduction in the ZnO by reactive substances (Figure S5), which were probably adsorbed onto the molecule surface from the LPME, with the generation of reactive oxygen species, such as hydrogen peroxide radicals, superoxide radicals, etc.