Biosynthesis of TiO2 and ZnO nanoparticles by Halomonas elongata IBRC-M 10214 in different conditions of medium

Abstract

Introduction: In the recent years, green synthesis is a novel method without some disadvantages of physical and chemical methods. In this approach, bacteria, archaebacteria, fungi, and plants may be applied without utilizing toxic and expensive materials for metal nanoparticles (MNPs) preparation. Methods: In this study, we used Taguchi method to obtain optimum conditions in titanium dioxide and zinc oxide nanoparticle (NPs) biosynthesis by Halomonas elongata IBRC-M 10214. Design and analysis of Taguchi experiments (an orthogonal assay and analysis of variance [ANOVA]) carried out by the Qualitek-4 software. Effects of TiO(OH)2, incubation temperature, and culturing time for synthesis of TiO2 NPs as well as ZnCl2 concentration, glucose concentration, and incubation temperature for the preparation of ZnO NPs were evaluated as the controllable factors with 3 levels. Characterization of TiO2 and ZnO NPs were determined by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and dynamic light scattering (DLS) analysis. Also, the antimicrobial properties of these NPs were investigated based on agar diffusion assay of NPs dispersed in batch cultures using Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 43300 as multidrug-resistant (MDR) bacteria. Results: It was evaluated that TiO2 and ZnO NPs had respectively average diameter sizes of 104.63±27.75 and 18.11±8.93 nm with spherical shapes. In contrast to the TiO2 NPs without antibacterial activity, the ZnO NPs had antibacterial effects at 0.1 and 0.01 M of (ZnCl2). Conclusion: The ZnO NPs have the antibacterial effect that can be operative in the medicinal aspect for fighting against prominent MDR bacteria such as E. coli ATCC 25922 and S. aureus ATCC 43300. In total, this study presents a simple method in the biosynthesis of TiO2 and ZnO NPs with low the expense, eco-friendly, and high productivity properties.

Effect of Incubation Time, CuSO4 and Glucose Concentrations on Biosynthesis of Copper Oxide (CuO) Nanoparticles with Rectangular Shape and Antibacterial Activity: Taguchi Method Approach

“…7). Compared to our previous investigation, E. coli and S. aureus had maximum IZD with 10 and 8.7 mm for biosynthesized Cu NPs [33].…”

“…As shown in this figure, CuSO 4 concentrations had more effect on CuO NPs biosynthesis compared to other parameters. These values in previous investigation were 0.904 (level 1) and 0.819 (level 2) for CuSO 4 and glucose parameters respectively [33].…”

“…In this design of experiment, the proper selection of factors and their levels are first step [39]. Therefore, in order to optimize experimental conditions, all the combination experiments were conducted using the assigned parameter values [40].…”

“…Basically, Taguchi method is a considerable approach to remove these obstacles in experiment design [52]. Therefore, similar to our previous studies, Taguchi method was used for achieving optimum conditions based on the selection of three parameters (incubation times, CuSO 4 and glucose concentrations) [25,33,53]. The orthogonal array of Taguchi experimental design for biological synthesis of CuO NPs was demonstrated in Table 1.…”

“…In contrast to the herbal type, biosynthesis of NPs by bacteria does not have the disadvantages of high polydispersity index (PDI) in NPs production due to the lack of multiple secondary metabolites including polyphenols and flavonoids [31]. In the case of bacterial approach for biosynthesis of NPs, it can utilize culture supernatant [32,33], bacterial biomass [34], cell-free extract [35], and bacterial derived components [36]. Therefore, in this study, we used culture supernatant as the extracellular approach of biosynthesis CuO NPs due to the simple recovery of NPs compared to the intracellular mode [37].…”