## 3 Results and Discussion  
The extracts from _Pantoea_ and _Raoultella_ bacteria were able to reduce Ag\({}^{+}\) to Ag\({}^{\circ}\) in an aqueous environment at basic pH after an incubating period of 48 h at 33 \({}^{\circ}\)C. According to [PERSON] and co-workers, microbial cells secrete enzymes (reductases) that reduce metal ions to the metallic state, enabling the formation of nanoparticles [29]. During the centrifugation process, the bacterial cells were separated from the enzymatic extracts (cell-free culture supernatant). The supernatant was then used in further experiments in our research. The reaction was followed by a color change of the colloids containing the supernatant and the aqueous AgNO\({}_{3}\) from light yellow to brownish, suggesting the formation of NPs [30]. The appearance of the brownish color occurs due to surface plasmon resonance phenomena, which are characteristic of silver and silver chloride nanoparticles [23; 31]. The color of the control samples (1 mM AgNO\({}_{3}\) + liquid media used for growing bacteria) remained unchanged. The difference between the samples can be observed in Figure 1A. Figure 1B presents the visible UV absorption spectra of solutions containing Ag/AgCl NPs obtained using the _Pantoea_ and _Raoultella_ bacterial extracts. The spectra of the nanoparticles obtained due to the bioreduction activity of both bacterial extracts, _R. planticola_ and _P. agglomerans_, showed absorption peaks at 443 nm and 438 nm, respectively, which are specific for silver and silver chloride nanoparticles. Pure silver nanoparticles exhibit a typical plasmon resonance absorption band between \(\sim\)400-500 nm, while pure silver chloride nanoparticles exhibited an UV absorption band at approximately 250 nm. The reports confirmed that peaks of approximately 440 nm coincided with the plasmon resonance of silver nanoparticles combined with silver chloride nanoparticles [11; 24]. Since there is only one peak for each solution, we can associate the results with the spherical shape of the nanoparticles. The morphologies of nanoparticles help serve their various purposes, including antimicrobial activity applications. The shape of the nanoparticles dictates their application in therapeutical applications, such as particle adhesion, cell internalization, and distribution [32]. As reported, the position and number of spectral absorption peaks provide useful information about the shape and size of nanoparticles [33]. Surface plasmon resonance also depends on the traits of the chemical environment, namely the adsorbed species on the surface of the nanoparticles and the dielectric constant [34]. One of the effects of the collective oscillation of free electrons on the metallic particle surface is the strong surface plasmon resonance ability of silver nanoparticles. Particle size is the main factor for these oscillations and is also an important factor that helps in determining the specific wavelength range of the absorption in the visible spectrum [35]. In the colloid, the spherical shape and uniform distribution of Ag/AgCl nanoparticles are determined by the symmetrical shape of the SPR peak. A change in color has been determined in the solution from light yellow to brownish, indicating that Ag/AgCl nanoparticles induced SPR phenomena. With the help of XRD and SAED techniques, we were able to observe both the interaction and the difference between specific phases of the biosynthesized Ag/AgCl NPs [10]. The crystalline structure was established by the diffraction peaks shown in Figure 2, which match (according to the file standard 01-071-5209) to the crystallographic planes (111), (200), (220), (311), (222), and (440) specific to the face-centered cubic unit cell of the AgCl crystal [30]. The presence of concentric rings and diffraction dots as seen in the SAED patterns supports the fact that the nature of the AgCl and Ag nanoparticles is crystalline, as shown in Figure 3B [34].