## 3 Results and Discussion
As the methods used with the characteristic process parameters (precursor concentration, temperature of the process, etc.) influence the structure of the synthesized nanoparticles, their shape and size also influence their capacity for use in various fields, such as their antimicrobial and photocatalytic activity [40]. The antimicrobial activities of metallic silver chloride nanoparticles against several bacterial strains have been reported elsewhere [21]. Other bio-reduced Ag/AgCl NPs have demonstrated bacterial toxicity against several strains, including both Gram-positive (such as _Staphylococcus aureus_ and _Streptococcus pyrogens_) and Gram-negative (such as _Proteus vulgaris_, _Escherichia coli_ and _Pseudomonas aeruginosa_) pathogens [13; 36; 41]. Figure 5: Cross section and three-dimensional (3D) representation of AgCl NPs. In addition to the fact that the nanoparticles biosynthesized in this paper possess important antimicrobial activity against _Staphylococcus aureus_ and _Streptococcus pyogenes_, the results showed that the nanoparticles obtained also possess antibacterial potential against other Gram-positive bacteria, such as _Bacillus amyloidatefaciens_, or Gram-negative bacteria, such as _Salmonella_. Within the frame of this work, the antibiotic potential of Ag/AgCl NPs was assessed against four species using the agar disc diffusion method. Figure 6 shows the variation of the inhibition zone diameter for discs containing Ag/AgCl NPs together with antibiotics and the control antibiotic discs (6 mm). Compared to the chemical synthesis method, where possible chemical residues on nanoparticles may interact with biological systems, as well as the antibacterial effects of antibiotics, we manage to aid the synthesis of nanoparticles which are more biocompatible through the use of green methods [42]. It can be observed that two types of antibiotics (ciprofloxacinacin 5 ug and erythromycincin 15 ug) were used for the strain of _Staphylococcus aureus_ to determine the synergism between these and AgCl NPs. Two types of antibiotics were also used for _Streptococcus pyogenes_ (vancomycin 30 ug and erythromycincin 15 ug). For _Salmonella_ and _Bacillus amyloidatefaciens_, synergism was determined using only ciprofloxacin 5 ug. The antibacterial potential of silver chloride nanoparticles can also be observed in Figure 7, where the percentage increase in the antibacterial effect of antibiotics with AgCl NPs on the test strains is represented graphically (Equation (1)). Multiple bar graphs have been used to point out the stages where fold has increased. The highest value was noticed in the case when vancomycin was combined with nanoparticles synthesized by _R. planticola_ against the test pathogen _S. pyogenes_, showing an increase in activity by 19.1%. The nanoparticles synthesized by _P. agglomerans_ showed the highest fold increase activity (17.4%) in combination with erythromycincin against _S. aureus_. A study conducted on the same subject by [PERSON] et al. concluded that synergism between antibiotics and metallic nanoparticles led to increased antipathogenic activity [43]. Figure 6: Diameter of inhibition zones for the bacterial strains tested with Ag/AgCl NPs disks, antibiotic disks, and the effect of synergism between AgCl NPs + antibiotics. CIP: ciprofloxacin; E: erythromycincin; VA: vancomycin. The antimicrobial potential of silver and silver chloride nanoparticles tested through the disc diffusion method is showed photographically in Figure 8. After 24 h incubation, a difference in the inhibition diameter zone can be observed between the control samples (consisting of discs with ciprofloxacin 5 \(\upmu\)g, vancomycin 30 \(\upmu\)g, or erythromycinromycin 15 \(\upmu\)g) and antibiotics in combination with bio-reduced nanoparticles. Figure 8: Images of the inhibition zone of _Staphylococcus aureus_, _Streptococcus pyogenes_, _Salmonella_, and _Bacillus amyloliquefaciens_ in the presence of erythromycinycin, ciprofloxacin, and vancomycin, respectively.