## 4 Discussion
It is believed that H\({}_{2}\)O\({}_{2}\) radicals can permeate the cell membranes of bacteria, cause damage, and restrict cell growth because the bacterial cell membrane is relatively permeable to them [86]. Moreover, it was demonstrated that the antibacterial activity of ZnO NPs could occur even in the dark, which indicates the possibility of the presence of other mechanisms apart from those that require UV irradiation for the production of ROS in the absence of light. The negatively charged bacterial cell [87; 88] allows strong electrostatic binding between the nanoparticles and bacterium surface, thus producing cell membrane damage that leads to the leakage of the intracellular content [89; 90]. Our SEM image (Figures 4 and 5) showed the adherence of the LP-ZnO NPs to the microbial cell surfaces. Furthermore, our research findings revealed that all the tested substances had lower MICs and MBCs/MFs against almost all the tested bacteria and fungi in both water and DMSO, except for _P. aeruginosa_ in water, which suggests the higher antimicrobial potential of nanoparticles. It is worth noting that the examined antimicrobial substances were significantly more active against _S. aureus_, _A. terrus_, and _A. niger_ in water than DMSO (Figure 2). A clearer picture of how the tested microbes interacted with the ZnO nanoparticles in water and DMSO can be seen in the fact that the 100 mg LP-ZnO NPs exhibited the highest activity against both bacteria and fungi in DMSO, as seen in the MIC and MBC results. Both the 50 mg and 100 mg LP-ZnO NPs in water had similar antimicrobial effects (Figure 3). Meanwhile, _S. aureus_ was the most susceptible microbe to damage by the tested antimicrobial substances, while _P. aeruginosa_ was the least. In other words, the Gram-positive _S. aureus_ requires a lower MIC, versus the higher MIC required for Gram-negative _P. aeruginosa_. The ability to create specific compounds that boost their resistance to oxidative stress is inherent to Gram-negative bacteria [82]. _S. aureus_, which is a food-producing enterotoxin bacterium, is primarily responsible for most food poisoning cases and a multitude of foodborne illnesses. It shares with other bacteria the extraordinary capacity to withstand the administration of any antibiotic [5]. Similar results from previous research on Gram-positive and Gram-negative bacteria have already been reported [91; 92]. Furthermore, the tested nanoparticles showed higher effect sizes on the MICs and MBCs/MFs than on the ZIs (Table S2). Our findings concluded that the activity of the synthesized LP-ZnO NPs was more potent than those of commercial antibiotics, such as augmentin and voriconazole, and that it was influenced by the solvent type and microorganism type. The SEM imaging of the tested bacteria and fungi strains after the LP-ZnO-NP treatment showed alterations to and damage on the cell wall surface, which confirms the antimicrobial potency of the studied ZnO nanoparticles (Figures 4 and 5). This was noticed in the severe damage to the cell membranes of all the tested microbes, and especially _P. aeruginosa_, _A. niger_, and _S. aureus_. The inadequacy of DMSO as a solvent for augmenting and voriconazole could adversely affect their antimicrobial activities. [PERSON] et al. [69] reported similar distortions in the cell membrane of _S. aureus_ with an accumulation of ZnO nanoparticles. Our SEM findings conformed to those reported previously on bacteria and fungi [93; 94; 95]. [PERSON] et al. [96] demonstrated that ZnO nanorods have both fungicide and fungistatic action against _Candida albicans_, which is consistent with our MFC and SEM results. ZnO nanoparticles can be used with anti-inflammatory drugs and antibiotics to boost the antimicrobial action against pathogenic bacteria without developing antibiotic resistance in nonclinical and clinical settings [86].